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19 pages, 1000 KiB

Open AccessArticle

Effect of Deficit Irrigation on Agronomic and Physiological Performance of Pomegranate (Punica granatum L.)

by Rossana Porras-Jorge, José Mariano Aguilar, Carlos Baixauli, Julián Bartual, Bernardo Pascual and Nuria Pascual-Seva

Plants 2025, 14(2), 164; https://doi.org/10.3390/plants14020164 - 8 Jan 2025

Viewed by 470

Abstract

Abstract: Agriculture accounts for over 70% of global freshwater consumption, with increasing competition for water resources due to climate change and rising urban and industrial demands. This study analyzes the effect of deficit irrigation (DI) on the agronomic and physiological performance of pomegranate [...] Read more.

Abstract: Agriculture accounts for over 70% of global freshwater consumption, with increasing competition for water resources due to climate change and rising urban and industrial demands. This study analyzes the effect of deficit irrigation (DI) on the agronomic and physiological performance of pomegranate (Punica granatum L.) in a Mediterranean climate. Deficit irrigation strategies, including sustained deficit irrigation (SDI) and regulated deficit irrigation (RDI), were evaluated against a control with full irrigation. The research was conducted over two growing seasons (2022–2023) at the Cajamar Experimental Centre in Paiporta, Valencia, Spain. RDI strategies achieved approximately 10% water savings without compromising marketable yield or fruit weight, while SDI resulted in significant water savings (~50%) but with a notable reduction in marketable yield, particularly in hot and dry conditions. SDI also reduced tree growth in height and trunk diameter compared to RDI and control strategies. The study concludes that RDI is a viable irrigation strategy for pomegranate cultivation under water-limited conditions, whereas SDI should be reserved for situations of severe water scarcity. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Seasonal variation of daily maximum (Tmax; red) and minimum (Tmin; blue) temperatures (°C), reference evapotranspiration (ETo; mm; yellow), and precipitation (mm; gray vertical bars) in 2022 (left) and 2023 (right). Full article ">Figure 2
Seasonal variation of volumetric soil water content (VSWC), air vapor pressure deficit (VPD in black), stem water potential (Ψstem), and stomatal conductance (gs) registered in the different irrigation treatments (Control in green; RDI1 in blue; RDI2 in yellow; SDI in red) in 2022 (left) and 2023 (right). All measures correspond to midday. Discontinuous vertical lines represent the start and end of the water restriction periods in RDI1 (blue) and RDI2 (yellow). Vertical bars represent the standard error. Full article ">Figure 3
Linear correlation between midday stem water potential (Ψstem, MPa) and stomatal conductance (gs, mmol m−2 s−1) with volumetric soil water content [VSWC, (%); left] and air vapor pressure deficit (VPD, kPa; right) for Control (green) and sustained deficit irrigation (SDI; red) strategies. Obtained from values corresponding to 2022 and 2023. Full article ">Figure 4
Linear correlation between midday stomatal conductance (gs, mmol m−2 s−1) and stem water potential (Ψstem, MPa), obtained from values corresponding to 2022 and 2023. Full article ">

20 pages, 6868 KiB

Open AccessArticle

Characterizing Droughts During the Rice Growth Period in Northeast China Based on Daily SPEI Under Climate Change

by Tangzhe Nie, Xiu Liu, Peng Chen, Lili Jiang, Zhongyi Sun, Shuai Yin, Tianyi Wang, Tiecheng Li and Chong Du

Plants 2025, 14(1), 30; https://doi.org/10.3390/plants14010030 - 25 Dec 2024

Viewed by 314

Abstract

In agricultural production, droughts occurring during the crucial growth periods of crops hinder crop development, while the daily-scale standardized precipitation evapotranspiration index (SPEI) can be applied to accurately identify the drought characteristics. In this study, we used the statistical downscaling method [...] Read more.

In agricultural production, droughts occurring during the crucial growth periods of crops hinder crop development, while the daily-scale standardized precipitation evapotranspiration index (SPEI) can be applied to accurately identify the drought characteristics. In this study, we used the statistical downscaling method to obtain the daily precipitation (P_r), maximum air temperature (T_max) and minimum air temperature (T_min) during the rice growing season in Heilongjiang Province from 2015 to 2100 under the SSP1-2.6, SSP2-4.5 and SSP5-8.5 in CMIP6, to study the spatial and temporal characteristics of drought during the rice growing season in cold region and the effect of climate change on drought characteristics. The potential evapotranspiration (PET₀) was calculated using the regression correction method of the Hargreaves formula recommended by the FAO, and the daily SPEI was calculated to quantitatively identify the drought classification. The Pearson correlation coefficient was used to analyze the correlation between the meteorological factors (P_r, T_max, T_min), PET₀ and SPEI. The results showed that: (1) Under 3 SSP scenarios, P_r showed an increasing trend from the northwest to the southeast, T_max showed an increasing trend from the northeast to the southwest, and higher T_min was mainly distributed in the east and west regions. (2) PET₀ indicated an overall interannual rise in the three future SSP scenarios, with higher values mainly distributed in the central and western regions. The mean daily PET₀ values ranged from 4.8 to 6.0 mm/d. (3) Under SSP1-2.6, rice mainly experienced mild drought and moderate drought (−0.5 ≥ SPEI > −1.5). The predominant drought classifications experienced were mild, moderate, and severe drought under SSP2-4.5 and SSP8.5 (−0.5 ≥ SPEI > −2.0). (4) The tillering stage experienced the highest drought frequency and drought intensity, with the longest drought lasting 24 days. However, the heading flower stage had the lowest drought frequency and drought intensity. The drought barycenter was mainly in Tieli and Suihua. (5) The PET₀ was most affected by the T_max, while the SPEI was most affected by the P_r. This study offers a scientific and rational foundation for understanding the drought sensitivity of rice in Northeast China, as well as a rationale for the optimal scheduling of water resources in agriculture in the future. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Trends of Pr (a1–a3), Tmax (b1–b3) and Tmin (c1–c3) under SSP1-2.6, SSP2-4.5 and SSP5-8.5 during each growth period of rice from 2015 to 2100. Pr, Tmax and Tmin represent precipitation, maximum air temperature and minimum air temperature, respectively. The 2030s, 2060s and 2090s represent the period of 2015–2040, 2041–2070 and 2071–2100, respectively. A, B, C, D, E and F represent the returning green stage, tillering stage, jointing booting stage, heading flower stage, milk stage and yellow ripening stage of rice, respectively. In the box-plot, the red line, the black square and the diamond represent the median, the mean and the outliers, respectively. Full article ">Figure 2
Spatiotemporal distribution of PET0 under SSP1-2.6 (a1–a4), SSP2-4.5 (b1–b4) and SSP5-8.5 (c1–c4) during the rice growth period from 2015 to 2100. The 2030s, 2060s and 2090s represent the period of 2015–2040, 2041–2070 and 2071–2100, respectively. A, B, C, D, E and F represent the returning green stage, tillering stage, jointing booting stage, heading flower stage, milk stage and yellow ripening stage of rice, respectively. In the box-plot, the red line, the black square and the diamond represent the median, the mean and the outliers, respectively. Full article ">Figure 3
Changing trend in SPEI and Mann-Kendall mutation analysis under SSP1-2.6 (a1,a2), SSP2-4.5 (b1,b2) and SSP5-8.5 (c1,c2) during the rice growth period from 2015 to 2100. Full article ">Figure 4
Distribution of Pij under SSP1-2.6 (a1–a4), SSP2-4.5 (b1–b4) and SSP5-8.5 (c1–c4) during the rice growth period from 2015 to 2100. The 2030s, 2060s and 2090s represent the period of 2015–2040, 2041–2070 and 2071–2100, respectively. A, B, C, D, E and F represent the returning green stage, tillering stage, jointing booting stage, heading flower stage, milk stage and yellow ripening stage of rice, respectively. In the box-plot, the red line, the black square and the diamond represent the median, the mean and the outliers, respectively. Full article ">Figure 5
Distribution of Du under SSP1-2.6 (a1–a4), SSP2-4.5 (b1–b4) and SSP5-8.5 (c1–c4) during the rice growth period from 2015 to 2100. The 2030s, 2060s and 2090s represent the period of 2015–2040, 2041–2070 and 2071–2100, respectively. A, B, C, D, E and F represent the returning green stage, tillering stage, jointing booting stage, heading flower stage, milk stage and yellow ripening stage of rice, respectively. In the box-plot, the red line, the black square and the diamond represent the median, the mean and the outliers, respectively. Full article ">Figure 6
Distribution of IN under SSP1-2.6 (a1–a4), SSP2-4.5 (b1–b4) and SSP5-8.5 (c1–c4) during the rice growth period from 2015 to 2100. The 2030s, 2060s and 2090s represent the period of 2015–2040, 2041–2070 and 2071–2100, respectively. A, B, C, D, E and F represent the returning green stage, tillering stage, jointing booting stage, heading flower stage, milk stage and yellow ripening stage of rice, respectively. In the box-plot, the red line, the black square and the diamond represent the median, the mean and the outliers, respectively. Full article ">Figure 7
The trajectory of the drought barycenter under SSP1-2.6 (a1–f1), SSP2-4.5 (a2–f2) and SSP5-8.5 (a3–f3) during each growth period of rice from 2015 to 2100. A, B, C, D, E and F represent the returning green stage, tillering stage, jointing booting stage, heading flower stage, milk stage and yellow ripening stage of rice, respectively. Full article ">Figure 8
Overview of the study area. Full article ">

14 pages, 2347 KiB

Open AccessArticle

Optimizing Irrigation Strategies to Improve Yield and Water Use Efficiency of Drip-Irrigated Maize in Southern Xinjiang

by Qingyong Bian, Zhiduo Dong, Yanbo Fu, Yupeng Zhao, Yaozu Feng, Zhiguo Wang and Jingquan Zhu

Plants 2024, 13(24), 3492; https://doi.org/10.3390/plants13243492 - 13 Dec 2024

Viewed by 737

Abstract

The contradiction between increased irrigation demand and water scarcity in arid regions has become more acute for crops as a result of global climate change. This highlights the urgent need to improve crop water use efficiency. In this study, four irrigation volumes were [...] Read more.

The contradiction between increased irrigation demand and water scarcity in arid regions has become more acute for crops as a result of global climate change. This highlights the urgent need to improve crop water use efficiency. In this study, four irrigation volumes were established for drip-irrigated maize under plastic mulch: 2145 m³ ha⁻¹ (W1), 2685 m³ ha⁻¹ (W2), 3360 m³ ha⁻¹ (W3), and 4200 m³ ha⁻¹ (W4). The effects of these volumes on soil moisture, maize growth, water consumption, crop coefficients, and yield were analyzed. The results showed that increasing the irrigation volume led to a 2.86% to 8.71% increase in soil moisture content, a 24.56% to 47.41% increase in water consumption, and a 3.43% to 35% increase in the crop coefficient. Maize plant height increased by 16.34% to 42.38%, ear height by 16.85% to 51.01%, ear length by 2.43% to 28.13%, and yield by 16.96% to 39.24%. Additionally, soil temperature was reduced by 1.67% to 5.67%, and the maize bald tip length decreased by 6.62% to 48%. The irrigation water use efficiency improved by 6.57% to 28.89%. A comprehensive evaluation using the TOPSIS method demonstrated that 3360 m³ ha⁻¹ of irrigation water was an effective irrigation strategy for increasing maize yield under drip irrigation with plastic mulch in the southern border area. Compared to 4200 m³ ha⁻¹, this strategy saved 840 m³ ha⁻¹ of irrigation water, increased the irrigation water use efficiency by 23.96%, and resulted in only a 0.84% decrease in yield. The findings of this study provide a theoretical foundation for optimizing production benefits in the context of limited water resources. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Changes in soil moisture and temperature during the maize growing period. (A) represents the fluctuation of soil moisture, while (B) represents the alteration of soil temperature. Full article ">Figure 2
Effects of irrigation volume on maize plant height, ear height, ear length, and bald tip length. (A) represents the fluctuation of maize plant height, while (B) represents ear height. (C) represents ear height, and (D) represents bald tip length. Different lowercase letters indicate a significant difference in the mean value of different treatments at the probability level of 0.05 (p < 0.05), determined by a one-way analysis of variance (ANOVA) and Duncan’s post hoc test. The data are presented as means ± standard deviation (SD) calculated from nine maize samples. Full article ">Figure 3
Soil water consumption during maize development. Full article ">Figure 4
Impact of irrigation on maize yield and water use efficiency. Different lowercase letters indicate a significant difference in the mean value of different treatments at the probability level of 0.05 (p < 0.05), determined by one-way analysis of variance (ANOVA) and Duncan’s post hoc test. The data are presented as means ± standard deviation (SD) calculated from nine maize samples. Full article ">Figure 5
Location and layout of the study area. Full article ">Figure 6
Diagram of maize planting arrangement and drip irrigation system. Full article ">Figure 7
The 2023 meteorological data for the study area. Full article ">

18 pages, 4852 KiB

Open AccessArticle

Optimizing Irrigation and Nitrogen Application to Enhance Millet Yield, Improve Water and Nitrogen Use Efficiency and Reduce Inorganic Nitrogen Accumulation in Northeast China

by Tangzhe Nie, Jianfeng Li, Lili Jiang, Zhongxue Zhang, Peng Chen, Tiecheng Li, Changlei Dai, Zhongyi Sun, Shuai Yin and Mengxue Wang

Plants 2024, 13(21), 3067; https://doi.org/10.3390/plants13213067 - 31 Oct 2024

Viewed by 867

Abstract

Enhancing irrigation and nitrogen fertilizer application has become a vital strategy for ensuring food security in the face of population growth and resource scarcity. A 2-year experiment was conducted to determine to investigate the effects of different irrigation lower limits and nitrogen fertilizer [...] Read more.

Enhancing irrigation and nitrogen fertilizer application has become a vital strategy for ensuring food security in the face of population growth and resource scarcity. A 2-year experiment was conducted to determine to investigate the effects of different irrigation lower limits and nitrogen fertilizer application amounts on millet growth, yield, water use efficiency (WUE), N utilization, and inorganic nitrogen accumulation in the soil in 2021 and 2022. The experiment was designed with four irrigation lower limits, corresponding to 50%, 60%, 70%, and 80% of the field capacity (FC), referred to as I₅₀, I₆₀, I₇₀, and I₈₀. Four nitrogen fertilizer application were also included: 0, 50, 100, and 150 kg·hm⁻² (designated as F₀₀, F₅₀, F₁₀₀, and F₁₅₀), resulting in a total of 16 treatments. Binary quadratic regression equations were established to optimize the irrigation and nitrogen application. The results demonstrated that the plant height, stem diameter, leaf area index, aboveground biomass, yield, spike diameter, spike length, spike weight, WUE, and nitrogen agronomic efficiency for millet initially increased before subsequently decreasing as the irrigation lower limit and nitrogen fertilizer application increased. Their maximum values were observed in the I₇₀F₁₀₀. However, the nitrogen partial factor productivity (PFPN) exhibited a gradual decline with increasing nitrogen application, reaching its peak at F₅₀. Additionally, PFPN displayed a pattern of initial increase followed by a decrease with rising irrigation lower limits. The accumulation of NO₃⁻-N and NH₄⁺-N in the 0~60 cm soil layer increased with the increase of nitrogen fertilizer application in both years, while they tended to decrease as the irrigation lower limit increased. An optimal irrigation lower limit of 64% FC to 74% FC and nitrogen fertilizer application of 80 to 100 kg ha⁻¹ was recommended for millet based on the regression equation. The findings of this study offer a theoretical foundation and technical guidance for developing a drip irrigation and fertilizer application for millet cultivation in Northeast China. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Plant height, stem diameter, leaf area index (LAI), and aboveground biomass of millet under different treatments in 2021 and 2022. I50, I60, I70, and I80 represent the irrigation lower limit being 50%, 60%, 70%, and 80% of the field capacity, respectively. F00, F50, F100, and F150 represent the nitrogen application amount of 0, 50, 100, and 150 kg·hm−2, respectively. Error bars represent one standard deviation about the mean. The letters above the bars are the mean separation indicators (LSD0.05), where similar letters indicate no significant difference. Full article ">Figure 2
Spike diameter, spike length, spike weight, and yield of millet under different treatments in 2021 and 2022. I50, I60, I70, and I80 represent the irrigation lower limit being 50%, 60%, 70%, and 80% of the field capacity, respectively. F00, F50, F100, and F150 represent the nitrogen application amount of 0, 50, 100, and 150 kg·hm−2, respectively. Error bars represent one standard deviation about the mean. The letters above the bars are the mean separation indicators (LSD0.05), where similar letters indicate no significant difference. Full article ">Figure 3
WUE, AEN, and PFPN of millet under different treatments in 2021 and 2022. I50, I60, I70, and I80 represent the irrigation lower limit being 50%, 60%, 70%, and 80% of the field capacity, respectively. F00, F50, F100, and F150 represent the nitrogen application amount of 0, 50, 100, and 150 kg·hm−2, respectively. Error bars represent one standard deviation about the mean. The letters above the bars are the mean separation indicators (LSD0.05), where similar letters indicate no significant difference. Full article ">Figure 4
NO3−-N and NH4+-N accumulation in the 0~60 cm soil profile at harvest in the millet root zone in 2021 and 2022. I50, I60, I70, and I80 represent the irrigation lower limit being 50%, 60%, 70%, and 80% of the field capacity, respectively. F00, F50, F100, and F150 represent the nitrogen application amount of 0, 50, 100, and 150 kg·hm−2, respectively. Error bars represent one standard deviation about the mean. The letters above the bars are the mean separation indicators (LSD0.05), where similar letters indicate no significant difference. Full article ">Figure 5
Relationship between yield, WUE, AEN, and PFPN under different irrigation lower limits and nitrogen fertilizer amounts. The red dots represent the measured values in 2021 and 2022. The green to red area represents the ≥95% confidence interval. FC: field capacity. Full article ">Figure 6
The geographical location of the study area. Full article ">Figure 7
The mean air temperature and daily rainfall recorded at the study area during the millet growth periods in 2021 and 2022. Full article ">

21 pages, 4700 KiB

Open AccessArticle

Simulation and Evaluation of Spring Maize Growth Under Drip Irrigation with Fully Biodegradable Film Mulching Based on the DSSAT Model

by Yanhui Jia, Haibin Shi, Qingfeng Miao, Xiulu Sun and Yayang Feng

Plants 2024, 13(21), 3027; https://doi.org/10.3390/plants13213027 - 29 Oct 2024

Viewed by 602

Abstract

Fully biodegradable mulch film enhances temperature and moisture retention during the early stages of maize growth while naturally degrading in the later stages, providing an environmentally friendly alternative to conventional plastic mulch films. However, there is no consensus on its impact on maize [...] Read more.

Fully biodegradable mulch film enhances temperature and moisture retention during the early stages of maize growth while naturally degrading in the later stages, providing an environmentally friendly alternative to conventional plastic mulch films. However, there is no consensus on its impact on maize growth and yield. The present study utilized field test data from spring maize covered with fully biodegradable mulch film in the Xiliaohe Plain, aiming to improve the Decision Support System for Agrotechnology Transfer (DSSAT) model while focusing on soil temperature, irrigation, rainfall, and evapotranspiration. The parameters of the DSSAT model were calibrated and validated using field test data from 2016 to 2018. The improved DSSAT model accurately simulated the maize growth process under various induction periods of fully biodegradable mulch film. The simulation accuracy of this model was as follows: MRE < 10%, nRMSE < 12%, and R² ≥ 0.80. Moreover, the yield of spring corn covered with fully biodegradable mulch film was predicted using meteorological data from 2019 to 2023. This study suggests that regions such as the Xiliaohe Plain, which share climatic conditions, should opt for fully biodegradable mulch film with an induction period of approximately 80 days to ensure high yields across different hydrological years. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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36 pages, 5248 KiB

Open AccessArticle

Growth, Evapotranspiration, Gas Exchange and Chl a Fluorescence of Ipê-Rosa Seedlings at Different Levels of Water Replacement

by Kalisto Natam Carneiro Silva, Andréa Carvalho da Silva, Daniela Roberta Borella, Samuel Silva Carneiro, Leonardo Martins Moura dos Santos, Matheus Caneles Batista Jorge, Beatriz Feltrin Magosso, Mariana Pizzatto and Adilson Pacheco de Souza

Plants 2024, 13(20), 2850; https://doi.org/10.3390/plants13202850 - 11 Oct 2024

Viewed by 826

Abstract

In general, young plants in the establishment phase demonstrate sensitivity to changes in environmental conditions, especially regarding water availability. The effects of the seasonality of biophysical processes on plant physiology can trigger differential responses, even within the same region, making it necessary to [...] Read more.

In general, young plants in the establishment phase demonstrate sensitivity to changes in environmental conditions, especially regarding water availability. The effects of the seasonality of biophysical processes on plant physiology can trigger differential responses, even within the same region, making it necessary to conduct studies that characterize the physiological performance of the species at different spatial and temporal scales, making it possible to understand their needs and growth limits under water stress conditions. This paper aimed to evaluate the growth, gas exchange and Chl a fluorescence in ipê-rosa seedlings subjected to levels of water replacement (LWRs) of 100, 75, 50 and 25% in a greenhouse. The morphometric variables of plant height, diameter at stem height, numbers of leaves and leaflets, root length and volume, plant dry mass and leaf area were evaluated. The potential evapotranspiration of seedlings (ETc) was obtained using direct weighing, considering the water replacement of 100% of the mass variation between subsequent days as a reference; the cultivation coefficients (kc) were obtained using the ratio between ETc and the reference evapotranspiration (ETo) obtained by the Penman–Monteith FAO-56 method. Biomass and evapotranspiration data were combined to determine water sensitivity. Diurnal fluxes of gas exchange (net photosynthesis rate, transpiration rate, stomatal conductance, internal and atmospheric carbon ratio, water use efficiency and leaf temperature) and Chl a fluorescence (Fv/Fm, Φ_PSII, ETR, Fv′/Fm′, NPQ and qL) were evaluated. Water restriction caused reductions of 90.9 and 84.7% in the increase in height and diameter of seedlings subjected to 25% water replacement when compared to seedlings with 100% water replacement. In comparison, biomass accumulation was reduced by 96.9%. The kc values increased throughout the seedling production cycle, ranging from 0.59 to 2.86. Maximum water sensitivity occurred at 50% water replacement, with Ky = 1.62. Maximum carbon assimilation rates occurred in the morning, ranging from 6.11 to 12.50 µmol m⁻² s⁻¹. Ipê-rosa seedlings regulate the physiology of growth, gas exchange and Chl a fluorescence depending on the amount of water available, and only 25% of the water replacement in the substrate allows the seedlings to survive. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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16 pages, 3963 KiB

Open AccessArticle

Effect of Delayed Irrigation at the Jointing Stage on Nitrogen, Silicon Nutrition and Grain Yield of Winter Wheat in the North China Plain

by Hao Zheng, Jinyang Sun, Yueping Liang, Caiyun Cao, Yang Gao, Junpeng Zhang, Hongkai Dang and Chunlian Zheng

Plants 2024, 13(18), 2648; https://doi.org/10.3390/plants13182648 - 21 Sep 2024

Viewed by 976

Abstract

Water scarcity is a key limitation to winter wheat production in the North China Plain, and it is essential to explore the optimal timing of spring irrigation to optimize N and Si uptake as well as to safeguard yields. The aim of this [...] Read more.

Water scarcity is a key limitation to winter wheat production in the North China Plain, and it is essential to explore the optimal timing of spring irrigation to optimize N and Si uptake as well as to safeguard yields. The aim of this study was to systematically study the effect mechanism of nitrogen and silicon absorption of winter wheat on yield under spring irrigation and to provide a scientific basis for optimizing irrigation strategy during the growth period of winter wheat. In this experiment, the winter wheat ‘Heng 4399’ was used. Five irrigation periods, i.e., 0 d (CK), 5 d (AJ5), 10 d (AJ10), 15 d (AJ15), and 20 d (AJ20) after the jointing stage, were set up to evaluate the nitrogen (N) and silicon (Si) absorption and grain yield (GY). The results showed that delayed irrigation for 5–10 days at the jointing stage had increased the GY. With the delay of irrigation time, the N/Si content of the entire plant at the maturity period increased first and then decreased; among that, the maximum N contents appeared in AJ15 and AJ5 in 2015 and 2020, respectively, while the Si concentrations appeared in AJ5 and AJ10 in sequence. Compared with AJ15 and AJ20, the N accumulation of vegetative organs in AJ5 increased by 3.05~23.13% at the flowering stage, 14.12~40.12% after the flowering stage, and a 1.76~6.45% increase in the N distribution rate at maturity stage. A correlation analysis revealed that the GY was significantly and positively correlated with the N/Si accumulation at the anthesis and N translocation after the anthesis stage. In conclusion, under limited irrigation conditions, delaying watering for 5 to 10 days at the jointing stage can improve the nitrogen and silicon absorption and nutrient status of wheat plants and increase wheat yield. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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14 pages, 2244 KiB

Open AccessArticle

Soybean Yield Simulation and Sustainability Assessment Based on the DSSAT-CROPGRO-Soybean Model

by Lei Zhang, Zhenxi Cao, Yang Gao, Weixiong Huang, Zhuanyun Si, Yuanhang Guo, Hongbo Wang and Xingpeng Wang

Plants 2024, 13(17), 2525; https://doi.org/10.3390/plants13172525 - 8 Sep 2024

Viewed by 1176

Abstract

In order to ensure national grain and oil security, it is imperative to expand the soybean planting area in the Xinjiang region. However, the scarcity of water resources in southern Xinjiang, the relatively backward soybean planting technology, and the lack of a supporting [...] Read more.

In order to ensure national grain and oil security, it is imperative to expand the soybean planting area in the Xinjiang region. However, the scarcity of water resources in southern Xinjiang, the relatively backward soybean planting technology, and the lack of a supporting irrigation system have negatively impacted soybean planting and yield. In 2022 and 2023, we conducted an experiment which included three irrigation amounts of 27 mm, 36 mm, and 45 mm and analyzed the changes in dry mass and yield. Additionally, we simulated the potential yield using the corrected DSSAT-CROPGRO-Soybean model and biomass based on the meteorological data from 1994 to 2023. The results demonstrated that the model was capable of accurately predicting soybean emergence (the relative root mean square error (nRMSE) = 0, the absolute relative error (ARE) = 0), flowering (nRMSE = 0, ARE = 2.78%), maturity (nRMSE = 0, ARE = 3.21%). The model demonstrated high levels of accuracy in predicting soybean biomass (R² = 0.98, nRMSE = 20.50%, ARE = 20.63%), 0–80 cm soil water storage (R² = 0.64, nRMSE = 7.78%, ARE = 3.24%), and yield (R² = 0.81, nRMSE = 10.83%, ARE = 8.79%). The biomass of soybean plants increases with the increase in irrigation amount. The highest biomass of 63 mm is 9379.19 kg·hm⁻². When the irrigation yield is 36–45 mm (p < 0.05), the maximum yield can reach 4984.73 kg·hm⁻²; the maximum efficiency of soybean irrigation water was 33–36 mm. In light of the impact of soybean yield and irrigation water use efficiency, the optimal irrigation amount for soybean cultivation in southern Xinjiang is estimated to be between 36 and 42 mm. The simulation results provide a theoretical foundation for soybean cultivation in southern Xinjiang. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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22 pages, 2364 KiB

Open AccessArticle

Water and Fertilizer Management Is an Important Way to Synergistically Enhance the Yield, Rice Quality and Lodging Resistance of Hybrid Rice

by Haijun Zhu, Lingli Nie, Xiaoe He, Xuehua Wang, Pan Long and Hongyi Chen

Plants 2024, 13(17), 2518; https://doi.org/10.3390/plants13172518 - 7 Sep 2024

Viewed by 951

Abstract

This study comprehensively investigated the synergistic effects and underlying mechanisms of optimized water and fertilizer management on the yield, quality, and lodging resistance of hybrid rice (Oryza sativa), through a two-year field experiment. Two hybrid rice varieties, Xinxiangliangyou 1751 (XXLY1751) and [...] Read more.

This study comprehensively investigated the synergistic effects and underlying mechanisms of optimized water and fertilizer management on the yield, quality, and lodging resistance of hybrid rice (Oryza sativa), through a two-year field experiment. Two hybrid rice varieties, Xinxiangliangyou 1751 (XXLY1751) and Yueliangyou Meixiang Xinzhan (YLYMXXZ), were subjected to three irrigation methods (W1: wet irrigation, W2: flooding irrigation, W3: shallow-wet-dry irrigation) and four nitrogen fertilizer treatments (F1 to F4 with application rates of 0, 180, 225, and 270 kg ha⁻¹, respectively). Our results revealed that the W1F3 treatment significantly enhanced photosynthetic efficiency and non-structural carbohydrate (NSC) accumulation, laying a robust foundation for high yield and quality. NSC accumulation not only supported rice growth but also directly influenced starch and protein synthesis, ensuring smooth grain filling and significantly improving yield and quality. Moreover, NSC strengthened stem fullness and thickness, converting them into structural carbohydrates such as cellulose and lignin, which substantially increased stem mechanical strength and lodging resistance. Statistical analysis demonstrated that water and fertilizer treatments had significant main and interactive effects on photosynthetic rate, dry matter accumulation, yield, quality parameters, NSC, cellulose, lignin, and stem bending resistance. This study reveals the intricate relationship between water and fertilizer management and NSC dynamics, providing valuable theoretical and practical insights for high-yield and high-quality cultivation of hybrid rice, significantly contributing to the sustainable development of modern agriculture. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Figure 1
(a,b) represent the tillering stages in 2022 and 2023, respectively; (c,d) represent the booting stages in 2022 and 2023, respectively; (e,f) represent the full heading stages in 2022 and 2023, respectively; (g,h) represent the grain filling stages in 2022 and 2023, respectively. Different lowercase letters on the error bars denote statistical differences (at the 0.05 level) among treatments of various varieties based on the LSD test. Significant differences within the same treatment are denoted by ns (p > 0.05), * (0.01 < p ≤ 0.05), and ** (p ≤ 0.01). Full article ">Figure 2
TDW of XXLY1751 (a) and YLYMXXZ (b) in 2022, and XXLY1751 (c) and YLYMXXZ (d) in 2023. Full article ">Figure 3
Figures (a,b) represent the yields of Xinxiangliangyou 1751 and Yueliangyou Meixiangxinzhan in 2022 and 2023, respectively. Different lowercase letters on the error bars indicate statistical differences (at a significance level of 0.05) between treatments of various cultivars in the LSD test. Significant differences within the same treatment are denoted by * (0.01 < p ≤ 0.05), and ** (p ≤ 0.01). Full article ">Figure 4
Head rice rate of XXLY1751 and YLYMXXZ in 2022 (a) and 2023 (b), and chalky grain rate of XXLY1751and YLYMXXZ in 2022 (c) and in 2023 (d). Different lowercase letters denote statistical differences between treatments of each season according to the LSD test (0.05). Significant differences within the same treatment are denoted by ns (p > 0.05), * (0.01 < p ≤ 0.05), and ** (p ≤ 0.01). Full article ">Figure 5
Protein content of XXLY1751 and YLYMXXZ in 2022 (a) and 2023 (b), and amylose content of XXLY1751and YLYMXXZ in 2022 (c) and 2023 (d). Different lowercase letters denote statistical differences between treatments of each season according to the LSD test (0.05). Significant differences within the same treatment are denoted by ns (p > 0.05), and ** (p ≤ 0.01). Full article ">Figure 6
Plant height at center of gravity and panicle length of XXLY1751 (a) and YLYMXXZ (b) in 2022, and XXLY1751 (c) and YLYMXXZ (d) in 2023. Full article ">Figure 7
(a,b) represent the full heading stages in 2022 and 2023, respectively; (c,d) represent the grain filling stages in 2022 and 2023, respectively; (e,f) represent the mature stage in 2022 and 2023, respectively. Different lowercase letters on the error bars denote statistical differences (at the 0.05 level) among treatments of various varieties based on the LSD test. Significant differences within the same treatment are denoted by ns (p > 0.05), * (0.01 < p ≤ 0.05), and ** (p ≤ 0.01). Full article ">Figure 8
Lignin and cellulose of XXLY1751 (a) and YLYMXXZ (b) in 2022, and XXLY1751 (c) and YLYMXXZ (d) in 2023. Different lowercase letters denote statistical differences between treatments of each season according to an LSD test (0.05). Full article ">Figure 9
SPS enzyme activity of XXLY1751 and YLYMXXZ in 2022 (a) and in 2023 (b), α-amylase activity of XXLY1751 and YLYMXXZ in 2022 (c) and in 2023 (d),and β-amylase activity of XXLY1751 and YLYMXXZ in 2022 (e) and in 2023 (f). Different lowercase letters denote statistical differences between treatments of each season according to an LSD test (0.05). Significant differences within the same treatment are denoted by * (0.01 < p ≤ 0.05), and ** (p ≤ 0.01). Full article ">Figure 10
Synergistic regulation of yield, quality, and lodging resistance by water and fertilizer management. Full article ">Figure 11
Water pipes and water meters in the community. Full article ">

19 pages, 11696 KiB

Open AccessArticle

Dry Matter Accumulation, Water Productivity and Quality of Potato in Response to Regulated Deficit Irrigation in a Desert Oasis Region

by Hengjia Zhang, Xietian Chen, Daoxin Xue, Wanheng Zhang, Fuqiang Li, Anguo Teng, Changlong Zhang, Lian Lei and Yuchun Ba

Plants 2024, 13(14), 1927; https://doi.org/10.3390/plants13141927 - 12 Jul 2024

Viewed by 1166

Abstract

As one of the most important food crops, the potato is widely planted in the oasis agricultural region of Northwest China. To ascertain the impact of regulated deficit irrigation (RDI) on various facets including dry matter accumulation, tuber yield, quality and water use [...] Read more.

As one of the most important food crops, the potato is widely planted in the oasis agricultural region of Northwest China. To ascertain the impact of regulated deficit irrigation (RDI) on various facets including dry matter accumulation, tuber yield, quality and water use efficiency (WUE) of potato plants, a two-growth season field experiment under mulched drip irrigation was conducted in the desert oasis region of Northwest China. Water deficits, applied at the seedling, tuber formation, tuber expansion and starch accumulation stages, encompassed two distinctive levels: mild (55–65% of field capacity, F_C) and moderate (45–55% F_C) deficit, with full irrigation (65–75% F_C) throughout the growing season as the control (CK). The results showed that water deficit significantly reduced (p < 0.05) above-ground dry matter, water consumption and tuber yield compared to CK, and the reduction increased with the increasing water deficit. A mild water deficit at the tuber formation stage, without significantly reducing (p > 0.05) yield, could significantly increase WUE and irrigation water use efficiency (IWUE), with two-year average increases of 25.55% and 32.33%, respectively, compared to CK. Water deficit at the tuber formation stage increased starch content, whereas water deficit at tuber expansion stage significantly reduced starch, protein and reducing sugar content. Additionally, a comprehensive evaluation showed that a mild water deficit at the tuber formation stage is the optimal RDI strategy for potato production, providing a good balance between yield, quality and WUE. The results of this study can provide theoretical support for efficient and sustainable potato production in the desert oasis regions of Northwest China. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Above-ground dry matter accumulation characteristics of potato plants at different stages under each water deficit treatment in 2016 (a) and 2018 (b). Different lowercase letters indicate significant differences between treatments at the p < 0.05 level. The bars represent the standard deviation. Full article ">Figure 2
Water consumption characteristics of potato plants at different growth stages under each water deficit treatment in 2016 (a,c) and 2018 (b,d). Different lowercase letters indicate significant differences between treatments at the p < 0.05 level. The bars represent the standard deviation. Full article ">Figure 3
Effect of different water deficits on potato plant WUE and IWUE in 2016 (a) and 2018 (b). Different lowercase letters indicate significant differences between treatments at the p < 0.05 level. The bars represent the standard deviation. Full article ">Figure 4
Effect of different water deficits on starch (a,b), protein (c,d) and reducing sugar (e,f) content of potato tubers in 2016 and 2018. Different lowercase letters indicate significant differences between treatments at the p < 0.05 level. The bars represent the standard deviation. Full article ">Figure 5
Location of the experiment station. Full article ">Figure 6
Monthly rainfall, mean evaporation and mean temperature during the potato growing season at the experimental site in 2016 (a) and 2018 (b). Full article ">Figure 7
Schematic layout of drip irrigation under film for potato plants. Full article ">

22 pages, 5745 KiB

Open AccessArticle

Exploring the Water–Soil–Crop Dynamic Process and Water Use Efficiency of Typical Irrigation Units in the Agro-Pastoral Ecotone of Northern China

by Guoshuai Wang, Xiangyang Miao, Bing Xu, Delong Tian, Jie Ren, Zekun Li, Ruiping Li, Hexiang Zheng, Jun Wang, Pengcheng Tang, Yayang Feng, Jie Zhou and Zhiwei Xu

Plants 2024, 13(14), 1916; https://doi.org/10.3390/plants13141916 - 11 Jul 2024

Viewed by 1104

Abstract

Groundwater resources serve as the primary source of water in the agro-pastoral ecotone of northern China, where scarcity of water resources constrains the development of agriculture and animal husbandry. As a typical rainfed agricultural area, the agro-pastoral ecotone in Inner Mongolia is entirely [...] Read more.

Groundwater resources serve as the primary source of water in the agro-pastoral ecotone of northern China, where scarcity of water resources constrains the development of agriculture and animal husbandry. As a typical rainfed agricultural area, the agro-pastoral ecotone in Inner Mongolia is entirely dependent on groundwater for agricultural irrigation. Due to the substantial groundwater consumption of irrigated farmland, groundwater levels have been progressively declining. To obtain a sustainable irrigation pattern that significantly conserves water, this study faces the challenge of unclear water transport relationships among water, soil, and crops, undefined water cycle mechanism in typical irrigation units, and water use efficiency, which was not assessed. Therefore, this paper, based on in situ experimental observations and daily meteorological data in 2022–2023, utilized the DSSAT model to explore the growth processes of potato, oat, alfalfa, and sunflower, the soil water dynamics, the water balance, and water use efficiency, analyzed over a typical irrigation area. The results indicated that the simulation accuracy of the DSSAT model was ARE < 10%, nRMSE/% < 10%, and R² ≥ 0.85. The consumption of the soil moisture during the rapid growth stage for the potatoes, oats, alfalfa, and sunflower was 7–13% more than that during the other periods, and the yield was 67,170, 3345, 6529, and 4020 kg/ha, respectively. The soil evaporation of oat, potato, alfalfa, and sunflower accounted for 18–22%, 78–82%; 57–68%, and 32–43%, and transpiration accounted for 40–44%, 56–60%, 45–47%, and 53–55% of ETa (333.8 mm–369.2 mm, 375.2 mm–414.2 mm, 415.7 mm–453.7 mm, and 355.0 mm–385.6 mm), respectively. It was advised that irrigation water could be appropriately reduced to decrease ineffective water consumption. The water use efficiency and irrigation water use efficiency for potatoes was at the maximum amount, ranging from 16.22 to 16.62 kg/m³ and 8.61 to 10.81 kg/m³, respectively, followed by alfalfa, sunflowers, and oats. For the perspective of water productivity, it was recommended that potatoes could be extensively cultivated, alfalfa planted appropriately, and oats and sunflowers planted less. The findings of this study provided a theoretical basis for efficient water resource use in the agro-pastoral ecotone of Northern China. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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14 pages, 2198 KiB

Open AccessArticle

Increasing Hybrid Rice Yield, Water Productivity, and Nitrogen Use Efficiency: Optimization Strategies for Irrigation and Fertilizer Management

by Haijun Zhu, Xiaoe He, Xuehua Wang and Pan Long

Plants 2024, 13(12), 1717; https://doi.org/10.3390/plants13121717 - 20 Jun 2024

Cited by 3 | Viewed by 1906

Abstract

Water and fertilizer are crucial in rice growth, with irrigation and fertilizer management exhibiting synergies. In a two-year field study conducted in Yiyang City, Hunan Province, we examined the impact of three irrigation strategies—wet-shallow irrigation (W1), flooding irrigation (W2), and the “thin, shallow, [...] Read more.

Water and fertilizer are crucial in rice growth, with irrigation and fertilizer management exhibiting synergies. In a two-year field study conducted in Yiyang City, Hunan Province, we examined the impact of three irrigation strategies—wet-shallow irrigation (W1), flooding irrigation (W2), and the “thin, shallow, wet, dry irrigation” method (W3)—in combination with distinct fertilizer treatments (labeled F1, F2, F3, and F4, with nitrogen application rates of 0, 180, 225, and 270 kg ha⁻¹, respectively) on rice yield generation and water–fertilizer utilization patterns. The study employed Hybrid Rice Xin Xiang Liang you 1751 (XXLY1751) and Yue Liang you Mei Xiang Xin Zhan (YLYMXXZ) as representative rice cultivars. Key findings from the research include water, fertilizer, variety, and year treatments, which all significantly influenced the yield components of rice. Compared to W2, W1 in 2022 reduced the amount of irrigation water by 35.2%, resulting in a 42.0~42.8% increase in irrigation water productivity and a 25.7~25.9% increase in total water productivity. In 2023, similar improvements were seen. Specifically, compared with other treatments, the W1F3 treatment increased nitrogen uptake and harvest index by 1.4–7.7% and 5.9–7.7%, respectively. Phosphorus and potassium uptake also improved. The W1 treatment enhanced the uptake, accumulation, and translocation of nitrogen, phosphorus, and potassium nutrients throughout the rice growth cycle, increasing nutrient levels in the grains. When paired with the F3 fertilization approach, W1 treatment boosted yields and improved nutrient use efficiency. Consequently, combining W1 and F3 treatment emerged as this study’s optimal water–fertilizer management approach. By harnessing the combined effects of water and fertilizer management, we can ensure efficient resource utilization and maximize the productive potential of rice. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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16 pages, 2004 KiB

Open AccessArticle

Root Zone Water Management Effects on Soil Hydrothermal Properties and Sweet Potato Yield

by Shihao Huang, Lei Zhao, Tingge Zhang, Minghui Qin, Tao Yin, Qing Liu and Huan Li

Plants 2024, 13(11), 1561; https://doi.org/10.3390/plants13111561 - 5 Jun 2024

Viewed by 1018

Abstract

Sufficient soil moisture is required to ensure the successful transplantation of sweet potato seedlings. Thus, reasonable water management is essential for achieving high quality and yield in sweet potato production. We conducted field experiments in northern China, planted on 18 May and harvested [...] Read more.

Sufficient soil moisture is required to ensure the successful transplantation of sweet potato seedlings. Thus, reasonable water management is essential for achieving high quality and yield in sweet potato production. We conducted field experiments in northern China, planted on 18 May and harvested on 18 October 2021, at the Nancun Experimental Base of Qingdao Agricultural University. Three water management treatments were tested for sweet potato seedlings after transplanting: hole irrigation (W₁), optimized drip irrigation (W₂), and traditional drip irrigation (W₃). The variation characteristics of soil volumetric water content, soil temperature, and soil CO₂ concentration in the root zone were monitored in situ for 0–50 days. The agronomy, root morphology, photosynthetic parameters, ¹³C accumulation, yield, and yield components of sweet potato were determined. The results showed that soil VWC was maintained at 22–25% and 27–32% in the hole irrigation and combined drip irrigation treatments, respectively, from 0 to 30 days after transplanting. However, there was no significant difference between the traditional (W₃) and optimized (W₂) drip irrigation systems. From 30 to 50 days after transplanting, the VWC decreased significantly in all treatments, with significant differences among all treatments. Soil CO₂ concentrations were positively correlated with VWC from 0 to 30 days after transplanting but gradually increased from 30 to 50 days, with significant differences among treatments. Soil temperature varied with fluctuations in air temperature, with no significant differences among treatments. Sweet potato survival rates were significantly lower in the hole irrigation treatments than in the drip irrigation treatments, with no significant difference between W₂ and W₃. The aboveground biomass, photosynthetic parameters, and leaf area index were significantly higher under drip irrigation than under hole irrigation, and values were higher in W₃ than in W₂. However, the total root length, root volume, and ¹³C partitioning rate were higher in W₂ than in W₃. These findings suggest that excessive drip irrigation can lead to an imbalance in sweet potato reservoir sources. Compared with W₁, the W₂ and W₃ treatments exhibited significant yield increases of 42.98% and 36.49%, respectively. The W₂ treatment had the lowest sweet potato deformity rate. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Figure 1
Dynamic variation in the soil volume moisture content, temperature, and CO2 content at 0–50 days. Note: (A) soil volume moisture content (%); (B) soil temperature (°C); (C) soil CO2 content (ppm). W1, W2, and W3, respectively, represent different experimental treatments. In this study, the effect of soil water vapor heat on stratification at 15 and 30 cm depths was investigated. However, it was found that the change rule of each factor at 15 and 30 cm depths was identical; thus, the use of an average value for soil water vapor heat to express the change rule. Full article ">Figure 2
Survival rate of sweet potato seedlings after transplanting under different treatments. Different lowercase letters indicate significant differences (p < 0.05). Full article ">Figure 3
Variation in the root morphological parameters under different treatments. Note: (A) root surface area (cm2 plant−1); (B) root volume (cm3 plant−1); (C) total root length (cm plant−1); (D) toot tips number (piece plant−1). W1, W2, and W3 represent different treatments. Different lowercase letters in each treatment showed significant difference (p < 0.05). Full article ">Figure 4
RDA analysis of soil internal environment and root morphological indices under different treatments. The coordinates of the first axis in the figure explain 95.06% of the variance, respectively, and the significances (according to Monte Carlo permutation tests) of all canonical axes were PA = 0.012, PB = 0.018, and PC = 0.026. Full article ">Figure 5
RDA analysis of physiological indices and agronomic indices of sweet potato under different treatments. The coordinates of the first axis in the figure explain 65.18% of the variance, respectively, and the significances (according to Monte Carlo permutation tests) of all canonical axes were PA = 0.012, PB = 0.018, and PC = 0.026. Full article ">

16 pages, 3065 KiB

Open AccessArticle

Long-Term Straw Incorporation under Controlled Irrigation Improves Soil Quality of Paddy Field and Rice Yield in Northeast China

by Peng Zhang, Peng Chen, Tangzhe Nie, Zhongxue Zhang, Tiecheng Li, Changlei Dai, Lili Jiang, Yu Wu, Zhongyi Sun and Shuai Yin

Plants 2024, 13(10), 1357; https://doi.org/10.3390/plants13101357 - 14 May 2024

Cited by 1 | Viewed by 1127

Abstract

Soil quality is an indicator of the ability to ensure ecological security and sustainable soil usage. The effects of long-term straw incorporation and different irrigation regimes on the yield and soil quality of paddy fields in cold regions remain unclear. This study established [...] Read more.

Soil quality is an indicator of the ability to ensure ecological security and sustainable soil usage. The effects of long-term straw incorporation and different irrigation regimes on the yield and soil quality of paddy fields in cold regions remain unclear. This study established four treatments: controlled irrigation + continuous straw incorporation for 3 years (C3), controlled irrigation + continuous straw incorporation for 7 years (C7), flooded irrigation + continuous straw incorporation for 3 years (F3), and flooded irrigation + continuous straw incorporation for 7 years (F7). Analysis was conducted on the impact of various irrigation regimes and straw incorporation years on the physicochemical characteristics and quality of the soil. The soil quality index (SQI) for rice fields was computed using separate datasets for each treatment. The soil nitrate nitrogen, available phosphorus, soil organic carbon, and soil organic matter contents of the C7 were 93.51%, 5.80%, 8.90%, and 8.26% higher compared to C3, respectively. In addition, the yield of the C7 treatment was 5.18%, 4.89%, and 10.32% higher than those of F3, C3, and F7, respectively. The validity of the minimum data set (MDS) was verified by correlation, E_f and E_R, which indicated that the MDS of all treatments were able to provide a valid evaluation of soil quality. The MDS based SQI of C7 was 11.05%, 11.97%, and 27.71% higher than that of F3, C3, and F7, respectively. Overall, long-term straw incorporation combined with controlled irrigation increases yield and soil quality in paddy fields in cold regions. This study provides a thorough assessment of soil quality concerning irrigation regimes and straw incorporation years to preserve food security and the sustainability of agricultural output. Additionally, it offers a basis for soil quality diagnosis of paddy fields in the Northeast China. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Soil (a) pH, (b) NH4+-N and NO3−-N, (c) AK and AP, (d) TN and DON, (e) SOC and SOM, (f) DOC, (g) MBC and MBN of paddy fields in different treatments. Abbreviations: pH: Soil pH; NH4+-N: Ammonium Nitrogen; NO3−-N: Nitrate Nitrogen; AK: Available Potassium; AP: Available Phosphorus; DOC: Dissolved Organic Carbon; SOC: Soil Organic Carbon; SOM: Soil Organic Matter; TN: Total Nitrogen; DON: Dissolved Organic Nitrogen; MBC: Microbial Carbon; MBN: Microbial Nitrogen. Full article ">Figure 1 Cont.
Soil (a) pH, (b) NH4+-N and NO3−-N, (c) AK and AP, (d) TN and DON, (e) SOC and SOM, (f) DOC, (g) MBC and MBN of paddy fields in different treatments. Abbreviations: pH: Soil pH; NH4+-N: Ammonium Nitrogen; NO3−-N: Nitrate Nitrogen; AK: Available Potassium; AP: Available Phosphorus; DOC: Dissolved Organic Carbon; SOC: Soil Organic Carbon; SOM: Soil Organic Matter; TN: Total Nitrogen; DON: Dissolved Organic Nitrogen; MBC: Microbial Carbon; MBN: Microbial Nitrogen. Full article ">Figure 2
Rice yields in different treatments. Note: I: irrigation regime; Y: year. Full article ">Figure 3
(a)TDS-SQI and (b)MDS-SQI of paddy soil in different treatments. Note: I: irrigation regime; Y: year. Full article ">Figure 4
Correlation analysis of rice yield and SQI under different treatments. Note: P is the correlation between SQI and yield. Full article ">Figure 5
Air temperature and precipitation during the rice growth period in 2023. Full article ">Figure 6
Comprehensive procedures for evaluating and analyzing soil quality. Full article ">

14 pages, 3700 KiB

Open AccessArticle

Optimization of a Lower Irrigation Limit for Lettuce Based on Comprehensive Evaluation: A Field Experiment

by Maomao Hou, Houdong Zhang, Hiba Shaghaleh, Jingnan Chen, Fenglin Zhong, Yousef Alhaj Hamoud and Lin Zhu

Plants 2024, 13(6), 853; https://doi.org/10.3390/plants13060853 - 15 Mar 2024

Viewed by 1787

Abstract

When optimizing irrigation methods, much consideration is given to crop growth indicators while less attention has been paid to soil’s gaseous carbon (C) and nitrogen (N) emission indicators. Therefore, adopting an irrigation practice that can reduce emissions while maintaining crop yield and quality [...] Read more.

When optimizing irrigation methods, much consideration is given to crop growth indicators while less attention has been paid to soil’s gaseous carbon (C) and nitrogen (N) emission indicators. Therefore, adopting an irrigation practice that can reduce emissions while maintaining crop yield and quality is of great interest. Thus, open-field experiments were conducted from September 2020 to January 2022 using a single-factor randomized block design with three replications. The lettuce plants (“Feiqiao Lettuce No.1”) were grown using four different irrigation methods established by setting the lower limit of drip irrigation to 75%, 65%, and 55% of soil water content at field capacity corresponding to DR1, DR2, and DR3, respectively. Furrow irrigation (FI) was used as a control. Crop growth indicators and soil gas emissions were observed. Results showed that the mean lettuce yield under DR1 (64,500 kg/ha) was the highest, and it was lower under DR3 and FI. The lettuces under DR3 showed greater concentrations of crude fiber, vitamin C, and soluble sugar, and a greater nitrate concentration. Compared with FI, the DR treatments were more conducive to improving the comprehensive quality of lettuce, including the measured appearance and nutritional quality. Among all the irrigation methods, FI had the maximum cracking rate of lettuce, reaching 25.3%, 24.6%, and 22.7%, respectively, for the three continuous seasons. The stem cracking rates under DR2 were the lowest—only 10.1%, 14.4%, and 8.2%, respectively, which were decreased to nearly half compared with FI. The entropy model detected that the weight coefficient evaluation value of DR2 was the greatest, reaching 0.93, indicating that the DR2 method has the optimal benefits under comprehensive consideration of water saving, yield increase, quality improvement, and emission reduction. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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The monthly rainfall. Full article ">Figure 2
The self-made device. Full article ">Figure 3
Effects of different irrigation methods on the lettuce yield. DR1, DR2, and DR3 represent lower irrigation limits at soil moisture contents of 75%, 65%, and 55% of the field capacity. FI is a furrow irrigation method using the same irrigation quota and regime as the DR2 treatment. The data are mean ± standard deviation. The significant differences among yield values of the different treatments in the same season were compared. The different letters (a, b, c) suggest significant differences at 0.05 level in terms of Duncan’s multiple range test. Full article ">Figure 4
Impacts of different irrigation schemes on the LAI of lettuce. ((a) the first season, (b) the second season, and (c) the third season) represent the first, second, or third cultivation season of lettuce. DR1, DR2, and DR3 represent lower irrigation limits at soil moisture contents of 75%, 65%, and 55% of the field capacity. FI is a furrow irrigation method using the same irrigation quota and regime as the DR2 treatment. Full article ">Figure 5
The average leaf area index of three seasons of lettuce under different irrigation methods (71 days after transplant). DR1, DR2, and DR3 represent lower irrigation limits at soil moisture contents of 75%, 65%, and 55% of the field capacity. FI is a furrow irrigation method using the same irrigation quota and regime as the DR2 treatment. The data are mean ± standard deviation. The letters, such as ‘a’ and ‘b’, suggest that there is a significant difference at the 0.05 level in terms of Duncan’s multiple range test. Full article ">Figure 6
Effects of the different irrigation systems on the cracking rate of lettuce stems for the three seasons. DR1, DR2, and DR3 represent lower irrigation limits at soil moisture contents of 75%, 65%, and 55% of the field capacity. FI is a furrow irrigation method using the same irrigation quota and regime as the DR2 treatment. The data used in the figure are mean ± standard deviation. The different letters like a, b, and c suggest that there were significant differences at the 0.05 level in terms of Duncan’s multiple range test. The significant differences among the stem cracking rate values of the different treatments in the same season were compared. Full article ">Figure 7
Evaluation value of entropy weight method for comprehensive benefits of water saving, yield increasing, quality improving, and emission reduction with different irrigation schemes. DR1, DR2, and DR3 represent lower irrigation limits at soil moisture contents of 75%, 65%, and 55% of the field capacity. FI is a furrow irrigation method using the same irrigation quota and regime as the DR2 treatment. Full article ">

21 pages, 3070 KiB

Open AccessArticle

Physiological Responses of a Grapefruit Orchard to Irrigation with Desalinated Seawater

by Josefa M. Navarro, Alberto Imbernón-Mulero, Juan M. Robles, Francisco M. Hernández-Ballester, Vera Antolinos, Belén Gallego-Elvira and José F. Maestre-Valero

Plants 2024, 13(6), 781; https://doi.org/10.3390/plants13060781 - 9 Mar 2024

Viewed by 1260

Abstract

Desalinated seawater (DSW) has emerged as a promising solution for irrigation in regions facing water scarcity. However, adopting DSW may impact the existing cultivation model, given the presence of potentially harmful elements, among other factors. A three-year experiment was carried out to assess [...] Read more.

Desalinated seawater (DSW) has emerged as a promising solution for irrigation in regions facing water scarcity. However, adopting DSW may impact the existing cultivation model, given the presence of potentially harmful elements, among other factors. A three-year experiment was carried out to assess the short-term effects of four irrigation waters—freshwater (FW), DSW, a mix 1:1 of FW and DSW (MW), and DSW with low boron (B) concentration (DSW–B)—on a ‘Rio Red’ grapefruit orchard. These irrigation waters exhibited varying levels of phytotoxic elements, some potentially harmful to citrus trees. Sodium (Na⁺) and chloride (Cl⁻) concentrations exceeded citrus thresholds in all treatments, except in DSW−B, whilst B exceeded toxicity levels in DSW and MW treatments. Leaf concentrations of Cl⁻ and Na⁺ remained low in all treatments, whereas B approached toxic levels only in DSW and MW–irrigated trees. The rapid growth of the trees, preventing excessive accumulation through a dilution effect, protected the plants from significant impacts on nutrition and physiology, such as gas exchange and chlorophyll levels, due to phytotoxic elements accumulation. Minor reductions in photosynthesis in DSW–irrigated trees were attributed to high B in leaves, since Cl⁻ and Na⁺ remained below toxic levels. The accelerated tree growth effectively prevented the substantial accumulation of phytotoxic elements, thereby limiting adverse effects on tree development and yield. When the maturation of trees reaches maximal growth, the potential accumulation of phytotoxic elements is expected to increase, potentially influencing tree behavior differently. Further study until the trees reach maturity is imperative for comprehensive understanding of the long-term effects of desalinated seawater irrigation. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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17 pages, 6037 KiB

Open AccessArticle

Evaluating the Effect of Deficit Irrigation on Yield and Water Use Efficiency of Drip Irrigation Cotton under Film in Xinjiang Based on Meta-Analysis

by Qi Xu, Xiaomei Dong, Weixiong Huang, Zhaoyang Li, Tongtong Huang, Zaijin Song, Yuhui Yang and Jinsai Chen

Plants 2024, 13(5), 640; https://doi.org/10.3390/plants13050640 - 26 Feb 2024

Cited by 4 | Viewed by 1789

Abstract

Water scarcity constrains the sustainable development of Chinese agriculture, and deficit irrigation as a new irrigation technology can effectively alleviate the problems of water scarcity and water use inefficiency in agriculture. In this study, the drip irrigation cotton field under film in Xinjiang [...] Read more.

Water scarcity constrains the sustainable development of Chinese agriculture, and deficit irrigation as a new irrigation technology can effectively alleviate the problems of water scarcity and water use inefficiency in agriculture. In this study, the drip irrigation cotton field under film in Xinjiang was taken as the research object. Meta-analysis and machine learning were used to quantitatively analyze the effects of different farm management practices, climate, and soil conditions on cotton yield and water use efficiency under deficit irrigation, to investigate the importance of the effects of different factors on cotton yield and water use efficiency, and to formulate appropriate optimization strategies. The results showed that deficit irrigation significantly increased cotton water use efficiency (7.39%) but decreased cotton yield (−15.00%) compared with full irrigation. All three deficit irrigation levels (80~100% FI, 60~80% FI, and 40~60% FI; FI: full irrigation) showed a significant decrease in cotton yield and a significant increase in water use efficiency. Under deficit irrigation, cotton yield reduction was the smallest and cotton water use efficiency increased the most when planted with one film, two tubes, a six-row cropping pattern, an irrigation frequency ≥10 times, a nitrogen application of 300~400 kg·ha⁻¹, and a crop density ≥240,000 per hectare, and planted with the Xinluzhong series of cotton varieties; deficit irrigation in areas with average annual temperature >10 °C, annual evapotranspiration >2000 mm, annual precipitation <60 mm, and with loam, sandy soil had the least inhibition of cotton yield and the greatest increase in cotton water use efficiency. The results of the random forest showed that the irrigation amount and nitrogen application had the greatest influence on cotton yield and water use efficiency. Rational irrigation based on optimal management practices under conditions of irrigation not less than 90% FI is expected to achieve a win–win situation for both cotton yield and water use efficiency. The above results can provide the best strategy for deficit irrigation and efficient water use in drip irrigation cotton under film in arid areas. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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15 pages, 3078 KiB

Open AccessArticle

Safe Farming: Ultrafine Bubble Water Reduces Insect Infestation and Improves Melon Yield and Quality

by Jo-Chi Hung, Ning-Juan Li, Ching-Yen Peng, Ching-Chieh Yang and Swee-Suak Ko

Plants 2024, 13(4), 537; https://doi.org/10.3390/plants13040537 - 16 Feb 2024

Viewed by 2574

Abstract

Melon pest management relies on the excessive application of pesticides. Reducing pesticide spraying has become a global issue for environmental sustainability and human health. Therefore, developing a new cropping system that is sustainable and eco-friendly is important. This study found that melon seedlings [...] Read more.

Melon pest management relies on the excessive application of pesticides. Reducing pesticide spraying has become a global issue for environmental sustainability and human health. Therefore, developing a new cropping system that is sustainable and eco-friendly is important. This study found that melon seedlings irrigated with ultrafine water containing H₂ and O₂ (UFW) produced more root hairs, increased shoot height, and produced more flowers than the control irrigated with reverse osmosis (RO) water. Surprisingly, we also discovered that UFW irrigation significantly reduced aphid infestation in melons. Based on cryo-scanning electron microscope (cryo-SEM) observations, UFW treatment enhanced trichome development and prevented aphid infestation. To investigate whether it was H₂ or O₂ that helped to deter insect infestation, we prepared UF water enrichment of H₂ (UF+H₂) and O₂ (UF+O₂) separately and irrigated melons. Cryo-SEM results indicated that both UF+H₂ and UF+O₂ can increase the density of trichomes in melon leaves and petioles. RT-qPCR showed that UF+H₂ significantly increased the gene expression level of the trichome-related gene GLABRA2 (GL2). We planted melons in a plastic greenhouse and irrigated them with ultrafine water enrichment of hydrogen (UF+H₂) and oxygen (UF+O₂). The SPAD value, photosynthetic parameters, root weight, fruit weight, and fruit sweetness were all better than the control without ultrafine water irrigation. UFW significantly increased trichome development, enhanced insect resistance, and improved fruit traits. This system thus provides useful water management for pest control and sustainable agricultural production. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Ultrafine water affected seed germination and rooting of melons. (A) Effects of ultrafine water (UFW) on melon seed germination. Four melon varieties, each with 40 seeds, were germinated in Petri dishes containing RO water and UFW. Arrows show the presence of root hairs on the root at 1 day after seed germination. (B) Germination rate of melon seeds at 7 days after germination. (C) Melon seedlings grown in plug trays containing peat moss at 7 days after sowing (DAS). Arrows show vigorous root development. Full article ">Figure 2
UFW irrigation affected the growth of melon seedlings. (A) The phenotype of melon potted plants at 14 days after transplantation (DAT). Red arrows indicate the fresh flowers, blue arrows indicate the wilting flowers. Bars, 10 cm. (B) Plant height of melons. Error bars represent the standard error of the mean (n = 10–21 per treatment). (C) Scatter plot of flower number per plant at 14 DAT. Horizontal lines indicate mean values (n = 10–21). *, significant differences between CK and UFW treatment were determined using Student’s t-test at p < 0.05 (B,C). Full article ">Figure 3
UFW irrigation affected aphid infestation on melon seedlings. (A) Phenotype of melon leaves attacked by aphids 14 days after transplantation. Scale bars, 2 mm. (B) Scatter plot of aphid infestation rating. A rating of 0 indicates no aphids were observed, and 9 indicates a high aphid density. Horizontal lines indicate mean values (n = 10–21). *, significant differences between CK and UFW treatment were determined using Student’s t-test at p < 0.05. (C) Aphids attacked the young flower buds of melon (arrowhead). Trichomes development after UFW treatment (arrow). (D) Cryo-SEM showed aphid infestation on flower buds of CK (D) and UFW (E). The arrowheads point to the aphids. Scale bars, 500 µm (D,E). Full article ">Figure 4
Hydrogen-rich or oxygen-rich ultrafine water irrigation affected the development of trichomes in melon cv. “Camilla”. (A) Dissecting microscope observation of the development of trichomes in melon petioles after irrigation with ultrafine water enrichment of hydrogen (UF+H2), oxygen (UF+O2), and RO water (Ck), respectively. Bars, 2 mm. (B) Cryo-scanning electron microscope (cryo-SEM) showing trichomes on the midribs of the melons. Blue arrows indicate the presence of granular trichomes. Bars, 500 µm. (C) Cryo-SEM showed the development of trichomes on the abaxial of newly established young leaves of melon (red arrows). Bars, 500 µm. (D) Trichome density in melon petioles irrigated with RO water, UF+H2, and UF+O2, n = 3 to 6. (E) RT-qPCR showed GLABRA2 (GL2) gene expression patterns in young melon leaves irrigated with UF+H2, UF+O2, and RO water control (CK). *, significant differences between CK and UFW treatment were determined using Student’s t-test at p < 0.05 (D,E). Full article ">Figure 5
Melon irrigated with hydrogen- and oxygen-rich ultrafine water altered jasmonic acid (JA) and methyl-JA (MeJA) contents, and gene expression patterns. (A) JA content. (B) MeJA content. (C) The gene expression level of JASMONATE ZIM DOMAIN PROTEIN (JAZ) and JA carboxyl methyltransferase (JMT). The gene expression level was normalized to two housekeeping genes: Actin (MELO3C023264) and ADP ribosylation factor 1 (ADP, MELO3C023630). Error bars represent the standard error of the mean (n = 3). Student’s t-test was used to find the significant difference between CK and UF+H2 or UF+O2 treatment. *, p < 0.05; ns, not significant. Full article ">Figure 6
Ultrafine water irrigation affected the photosynthesis capacity of melons. (A) Chlorophyll content in melons. The SPAD value was measured on the 4th leaf at the late stage of fruit maturity. n = 4 plants. The Li600 Porometer/Fluorometers meter detected the photosynthesis parameters of (B) stomatal conductance (gsw); (C) ΦPSII, the quantum yield of PSII calculated from fluorescence; and (D) the electron transport rate (ETR) of L1 melon leaves. Student’s t-test was used to find the significant difference between UFW and the regular tap water (CK). *, p < 0.05. Error bars represent the standard error of the mean (n = 4). Full article ">Figure 7
UFW irrigation affected fruit weight and sweetness of melon cv. “Camilla”. (A) Melons were planted in a greenhouse. Photo taken 42 days after pollination. Bars, 20 cm. (B) Root morphology at harvest stage. (C) Root fresh weight of each plant. (D) Root dry weight per plant. (E) Melon fruits at 5 days after harvest. (F) Average fruit weight of melon. (G) The sweetness of melon fruits. UF+H2, hydrogen-rich ultrafine water irrigation. UF+O2, oxygen-rich ultrafine water irrigation. CK, irrigated with tap water. Bars, standard deviation of 22 plants. Student’s t-test was used to find significant difference between CK and UF+H2 or UF+O2 treatment. *, p < 0.05. Full article ">

12 pages, 1827 KiB

Open AccessArticle

Water Deficit Diagnosis of Winter Wheat Based on Thermal Infrared Imaging

by Shouchen Ma, Saisai Liu, Zhenhao Gao, Xinsheng Wang, Shoutian Ma and Shengfeng Wang

Plants 2024, 13(3), 361; https://doi.org/10.3390/plants13030361 - 25 Jan 2024

Cited by 5 | Viewed by 1470

Abstract

Field experiments were conducted to analyze the effectiveness of the crop stress index (CWSI) obtained by infrared thermal imaging to indicate crop water status, and to determine the appropriate CWSI threshold range for wheat at different growth stages. The results showed that the [...] Read more.

Field experiments were conducted to analyze the effectiveness of the crop stress index (CWSI) obtained by infrared thermal imaging to indicate crop water status, and to determine the appropriate CWSI threshold range for wheat at different growth stages. The results showed that the sensitivity of plant physiological parameters to soil water was different at different growth stages. The sensitivity of stomatal conductance (Gs) and transpiration rate (Tr) to soil water was higher than that of leaf relative water content (LRWC) and photosynthetic rate (Pn). The characteristics of plant physiology and biomass (yield) at each growth stage showed that the plant production would not suffer from drought stress as long as the soil water content (SWC) was maintained above 57.0% of the field water capacity (FWC) during the jointing stage, 63.0% of the FWC during the flowering stage and 60.0% of the FWC during the filling stage. Correlation analysis showed that the correlation of CWSI with Gs, Tr and Pn was lower than that with LRWC and SWC at the jointing stage. CWSI was extremely significantly negatively correlated with SWC and LRWC (p < 0.01), but significantly negatively correlated with Gs, Tr and Pn (p < 0.05). At the flowering stage, CWSI was extremely significantly negatively correlated with all physiological and soil parameters (p < 0.01). The regression analysis showed that the CWSI of winter wheat was correlated with biomass (grain yield) in a curvilinear relationship at each growth stage. When the CWSI increased to a certain extent, the biomass and yield showed a decreasing trend with the increase in CWSI. Comprehensive analysis of all indexes showed that CWSI can be used as a decision-making index to guide the water-saving irrigation of winter wheat, as long as the CWSI threshold of plants was maintained at 0.26–0.38 during the jointing stage, 0.27–0.32 during the flowering stage and 0.30–0.36 during the filling stage, which could not only avoid the adverse effects of water stress on crop production, but also achieve the purpose of water saving. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Soil water content (SWC) under different treatments. Different letters in the same growing stage show significant differences among treatments (p < 0.05). CK: adequate irrigation; W1: moderate irrigation; W2: slight deficit irrigation; W3: severe deficit irrigation. Full article ">Figure 2
LRWC of plants under different treatments. Different letters in the same growing stage show significant differences among treatments (p < 0.05). CK: adequate irrigation; W1: moderate irrigation; W2: slight deficit irrigation; W3: severe deficit irrigation. Full article ">Figure 3
Stomatal behavior of plants under different treatments. Different letters in the same growing stage show significant differences among treatments (p < 0.05). CK: adequate irrigation; W1: moderate irrigation; W2: slight deficit irrigation; W3: severe deficit irrigation. Full article ">Figure 4
CWSI of plants under different treatments. Different letters in the same growing stage show significant differences among treatments (p < 0.05). CK: adequate irrigation; W1: moderate irrigation; W2: slight deficit irrigation; W3: severe deficit irrigation. Full article ">Figure 5
The relationship between CWSI and biomass and yield at different growth stages (2023). * indicates significant correlation at p< 0.05 levels. Full article ">Figure 6
The meteorological information during the growing seasons. Tmax: maximum temperature; Tmin: minimum temperature. Full article ">

19 pages, 3328 KiB

Open AccessArticle

Effects of Foliar Selenium Application on Oxidative Damage and Photosynthetic Properties of Greenhouse Tomato under Drought Stress

by Jiawen Song, Lang Xin, Fukui Gao, Hao Liu and Xingpeng Wang

Plants 2024, 13(2), 302; https://doi.org/10.3390/plants13020302 - 19 Jan 2024

Cited by 6 | Viewed by 1623

Abstract

Both drought stress and exogenous selenium (Se) cause changes in plant physiological characteristics, which are key factors affecting crop yield. Although Se is known to be drought-resistant for crops, its internal physiological regulatory mechanisms are not clear. This study analyzed the effects of [...] Read more.

Both drought stress and exogenous selenium (Se) cause changes in plant physiological characteristics, which are key factors affecting crop yield. Although Se is known to be drought-resistant for crops, its internal physiological regulatory mechanisms are not clear. This study analyzed the effects of selenium application (SeA) on antioxidant enzyme activities, osmoregulatory substance contents, and photosynthetic characteristics of greenhouse tomatoes under drought stress and related physiological mechanisms. The results showed that drought stress induced oxidative damage in cells and significantly increased the content of the membrane lipidation product malondialdehyde (MDA) and the osmoregulatory substance proline (p < 0.001) compared with the adequate water supply. The proline content of severe drought stress (W1) was 9.7 times higher than that of the adequate water supply (W3), and foliar SeA increased glutathione peroxidase (GSH-PX) activity, and SeA induced different enzymatic reactions in cells under different drought stresses; catalase (CAT) was induced under severe drought stress (p < 0.01) and was significantly increased by 32.1% compared with the clear water control, CAT. Peroxidase (POD) was induced under adequate water supply conditions (p < 0.01), which was significantly increased by 15.2%, and SeA attenuated cell membrane lipidation, which reduced MDA content by an average of 21.5% compared with the clear water control, and also promoted photosynthesis in the crop. Meanwhile, through the entropy weighting method analysis (TOPSIS) of the indexes, the highest comprehensive evaluation score was obtained for the S5W3, followed by the S2.5W3 treatment. Therefore, this study emphasized the importance of SeA to reduce oxidative damage and enhance photosynthesis under drought stress. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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MDA content of leaves in different treatments. MDA: Malondialdehyde. ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 2
GSH-PX activity of leaves under different treatments. Where “ns” indicates means not significant (p > 0.05), ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 3
SOD (a), POD (b), and CAT (c) activities of leaves in different treatments. ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 3 Cont.
SOD (a), POD (b), and CAT (c) activities of leaves in different treatments. ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 4
Proline content of leaves in different treatments. Where “ns” indicates means not significant (p > 0.05), ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 5
Soluble sugar content of leaves in different treatments. ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 6
Soluble protein content of leaves in different treatments. Where “ns” indicates means not significant (p > 0.05), ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 7
SPAD of leaves in different treatments. Where “ns” indicates means not significant (p > 0.05), ** indicates significant differences at p < 0.01. The means with the same small case letters are statistically non-significant. Full article ">Figure 8
Schematic diagram of SeA and irrigation system. Full article ">

17 pages, 7254 KiB

Open AccessArticle

Study on Modeling and Evaluating Alfalfa Yield and Optimal Water Use Efficiency in the Agro-Pastoral Ecotone of Northern China

by Xiangyang Miao, Guoshuai Wang, Ruiping Li, Bing Xu, Hexiang Zheng, Delong Tian, Jun Wang, Jie Ren, Zekun Li and Jie Zhou

Plants 2024, 13(2), 229; https://doi.org/10.3390/plants13020229 - 14 Jan 2024

Cited by 2 | Viewed by 1448

Abstract

The agro-pastoral ecotone in northern China is the main production area of agriculture and animal husbandry, in which agricultural development relies entirely on groundwater. Due to the increasing water consumption of groundwater year by year, groundwater resources are becoming increasingly scarce. The substantial [...] Read more.

The agro-pastoral ecotone in northern China is the main production area of agriculture and animal husbandry, in which agricultural development relies entirely on groundwater. Due to the increasing water consumption of groundwater year by year, groundwater resources are becoming increasingly scarce. The substantial water demand and low germination rate in the first year are the main characteristics of alfalfa (Medicago sativa L.) yield in the agro-pastoral ecotone in northern China. Due to unscientific irrigation, water resources are seriously wasted, which restricts the development of local agriculture and animal husbandry. The study constructed the Dssat-Forages-Alfalfa model and used soil water content, leaf area index, and yield data collected with in situ observation experiments in 2022 and 2023 to calibrate and validate the parameters. The study found ARE < 10%, E_NRMS < 15%, and R² ≥ 0.85. The model simulation accuracy was acceptable. The study revealed that the water consumption at the surface soil layer (0–20 cm) was more than 6~12% and 13~31% than that at the 20–40 cm and 40–60 cm soil layers, respectively. The study showed when the irrigation quota was 30 mm, the annual yield of alfalfa (Medicago sativa L.) (7435 kg/ha) was consistent with that of the irrigation quota of 33 mm, and increased by 3.99% to 5.34% and 6.86% to 10.67% compared with that of irrigation quotas of 27 mm and 24 mm, respectively. To ensure the germination rate of alfalfa (Medicago sativa L.), it is recommended to control the initial soil water content at 0.8 θ_fc~1.0 θ_fc, with an irrigation quota of 30 mm, which was the best scheme for water-use efficiency and economic yield. The study aimed to provide technological support for the rational utilization of groundwater and the scientific improvement of alfalfa yield in the agro-pastoral ecotone in northern China. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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21 pages, 3315 KiB

Open AccessArticle

Irrigation and Fertilization Scheduling for Peanut Cultivation under Mulched Drip Irrigation in a Desert–Oasis Area

by Jianshu Dong, Xiaojun Shen, Qiang Li, Zhu Xue, Xianfei Hou, Haocui Miao and Huifeng Ning

Plants 2024, 13(1), 144; https://doi.org/10.3390/plants13010144 - 4 Jan 2024

Cited by 3 | Viewed by 2248

Abstract

The aim of this study was to investigate the impact of water and nitrogen regulation on the characteristics of water and fertilizer demands and the yield, quality, and efficiencies of the water and nitrogen utilization of peanuts cultivated under mulched drip irrigation in [...] Read more.

The aim of this study was to investigate the impact of water and nitrogen regulation on the characteristics of water and fertilizer demands and the yield, quality, and efficiencies of the water and nitrogen utilization of peanuts cultivated under mulched drip irrigation in a desert–oasis region. The experiment, conducted in Urumqi, Xinjiang, centered on elucidating the response mechanisms governing peanut growth, yield, quality, water consumption patterns, and fertilizer characteristics during the reproductive period under the influence of water and nitrogen regulation. In the field experiments, three irrigation levels were implemented, denoted as W₁ (irrigation water quota of 22.5 mm), W₂ (irrigation water quota of 30 mm), and W₃ (irrigation water quota of 37.5 mm). Additionally, two nitrogen application levels, labeled N₁ (nitrogen application rate of 77.5 kg·ha⁻¹) and N₂ (a nitrogen application rate of 110 kg·ha⁻¹), were applied, resulting in seven treatments. A control treatment (CK), which involved no nitrogen application, was also included in the experimental design. The results indicate a direct correlation between the increment in the irrigation quota and increases in farmland water-related parameters, including water consumption, daily water consumption intensity, and water consumption percentage. The nitrogen harvest index (NHI) demonstrated a higher value in the absence of nitrogen application compared to the treatment with elevated nitrogen levels. The application of nitrogen resulted in an elevation in both nitrogen accumulation and nitrogen absorption efficiency within pods and plants. When subjected to identical nitrogen application conditions, irrigation proved to be advantageous in enhancing water-use efficiency (WUE), nitrogen partial factor productivity (NPFP), and the yield of peanut pods. The contribution rate of water to pod yield and WUE exceeded that of nitrogen, while the contribution rate of nitrogen to nitrogen-use efficiency (NUE) was higher. The total water consumption for achieving a high yield and enhanced water- and nitrogen-use efficiencies in peanuts cultivated under drip irrigation with film mulching was approximately 402.57 mm. Taking into account yield, quality, and water- and nitrogen-used efficiencies, the use of an irrigation quota of 37.5 mm, an irrigation cycle of 10–15 days, and a nitrogen application rate of 110 kg·ha⁻¹ can be regarded as an appropriate water and nitrogen management approach for peanut cultivation under mulched drip irrigation in Xinjiang. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Figure 1
Effects of water and nitrogen regulation on peanut yield and water-use efficiency under mulched drip irrigation. Note: W1, W2, and W3 represent irrigation water quotas of 22.5, 30, and 37.5 mm, respectively. N1 and N2 represent nitrogen application rates of 77.5 and 110 kg·ha−1, respectively. CK represents a 30 mm irrigation water quota and no nitrogen application. For each index, the mean values within a column followed by a different letter are significantly different at p ≤ 0.05 according to the LSD test ** indicates significance at the 0.01 probability level, respectively; ns: non-significant. Full article ">Figure 2
Structure block diagram of a comprehensive evaluation model for peanut growth under mulched drip irrigation. Full article ">Figure 3
Schematic diagram of the test site. Full article ">Figure 4
Daily variations in daily mean temperature (a), wind speed (b), photosynthetically active radiation (c), relative humidity (d), precipitation (e), and sunshine duration (f) during peanut growth period. Full article ">Figure 5
The actual irrigation and fertilization times, irrigation volumes, and nitrogen application rates during the peanut growth period. Note: W1, W2, and W3 represent irrigation water quotas of 22.5, 30, and 37.5 mm, respectively. N1 and N2 represent nitrogen application rates of 77.5 and 110 kg·ha−1, respectively. CK represents a 30 mm irrigation water quota and no nitrogen application. Full article ">Figure 6
Layout of drip irrigation in the peanut field under film mulching (mm). Full article ">Figure 7
Layout of the field experiment. Note: W1, W2, and W3 represent irrigation water quotas of 22.5, 30, and 37.5 mm, respectively. N1 and N2 represent nitrogen application rates of 77.5 and 110 kg·ha−1, respectively. CK represents a 30 mm irrigation water quota and no nitrogen application. Blank stands for blank film. Full article ">

15 pages, 2661 KiB

Open AccessArticle

Effects of Post-Anthesis Irrigation on the Activity of Starch Synthesis-Related Enzymes and Wheat Grain Quality under Different Nitrogen Conditions

by Lang Xin, Yuanyuan Fu, Shoutian Ma, Caixia Li, Hongbo Wang, Yang Gao and Xingpeng Wang

Plants 2023, 12(24), 4086; https://doi.org/10.3390/plants12244086 - 6 Dec 2023

Cited by 6 | Viewed by 1262

Abstract

To develop optimal management strategies for water and nitrogen fertilizer application in winter wheat cultivation, we conducted a potted experiment to investigate the effects of different irrigation levels and nitrogen fertilizer treatments on the activity of starch synthesis-related enzymes and the grain quality [...] Read more.

To develop optimal management strategies for water and nitrogen fertilizer application in winter wheat cultivation, we conducted a potted experiment to investigate the effects of different irrigation levels and nitrogen fertilizer treatments on the activity of starch synthesis-related enzymes and the grain quality of winter wheat. The potted experiment consisted of three irrigation levels, with the lower limits set at 50–55% (I₀), 60–65% (I₁), and 70–75% (I₂) of the field capacity. In addition, four levels of nitrogen fertilizer were applied, denoted as N₀ (0 kg N hm⁻²), N₁ (120 kg N hm⁻²), N₂ (240 kg N hm⁻²), and N₃ (300 kg N hm⁻²), respectively. The results revealed the significant impacts of irrigation and nitrogen treatments on the activities of key starch-related enzymes, including adenosine diphosphoglucose pyrophosphrylase (ADPG-PPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS), and starch branching enzymes (SBE) in wheat grains. These treatments also influenced the starch content, amylopectin content, and, ultimately, wheat yield. In summary, our findings suggest that maintaining irrigation at a lower limit of 60% to 65% of the field capacity and applying nitrogen fertilizer at a rate of 240 kg hm⁻² is beneficial for achieving both high yield and high quality in winter wheat cultivation. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Effects of different treatments of irrigation (a—I0, b—I1, and c—I2) and nitrogen fertilizer on the starch content in wheat grains during the grain-filling period. Data are the mean ± standard deviation (n = 3). The different letters on top of the error bars represent significant differences (p < 0.05). Full article ">Figure 2
Effects of the different treatments of irrigation (a—I0, b—I1, and c—I2) and nitrogen fertilizer on the amylopectin content in wheat grains during the grain-filling period. Data are the mean ± standard deviation (n = 3). The different letters on top of the error bars represent significant differences (p < 0.05). Full article ">Figure 3
Effects of the different treatments (a—I0, b—I1, and c—I2) on ADPG-PPase activity in wheat grains during the grain-filling period. Data are the mean ± standard deviation (n = 3). The different letters on top of the error bars represent significant differences (p < 0.05). Full article ">Figure 4
Effects of the different treatments (a—I0, b—I1, and c—I2) on SSS activity in wheat grains during the grain-filling period. Data are the mean ± standard deviation (n = 3). The different letters on top of the error bars represent significant differences (p < 0.05). Full article ">Figure 5
Effects of the different treatments (a—I0, b—I1, c—I2) on GBSS activity in wheat grains during the grain-filling period. Data are the mean ± standard deviation (n = 3). The different letters on top of the error bars represent significant differences (p < 0.05). Full article ">Figure 6
Effects of different treatments (a—I0, b—I1, c—I2) on SBE activity in wheat grains during the grain-filling period. Data are the mean ± standard deviation (n = 3). The different letters on top of the error bars represent significant differences (p < 0.05). Full article ">Figure 7
Rain, PAR, Tmax, and Tmin during the winter wheat growing season of 2022–2023. Full article ">

21 pages, 833 KiB

Open AccessArticle

Effects of Different Water and Nitrogen Supply Modes on Peanut Growth and Water and Nitrogen Use Efficiency under Mulched Drip Irrigation in Xinjiang

by Jianshu Dong, Zhu Xue, Xiaojun Shen, Ruochen Yi, Junwei Chen, Qiang Li, Xianfei Hou and Haocui Miao

Plants 2023, 12(19), 3368; https://doi.org/10.3390/plants12193368 - 24 Sep 2023

Cited by 4 | Viewed by 1700

Abstract

The optimization of irrigation and fertilization indexes for peanuts with drip irrigation is urgently needed in Xinjiang. A field experiment was conducted during the 2021 peanut growing season at Urumqi, Xinjiang, in Northwestern China, to evaluate the effects of different water and nitrogen [...] Read more.

The optimization of irrigation and fertilization indexes for peanuts with drip irrigation is urgently needed in Xinjiang. A field experiment was conducted during the 2021 peanut growing season at Urumqi, Xinjiang, in Northwestern China, to evaluate the effects of different water and nitrogen treatments on the growth, yield, and water and nitrogen utilization of peanuts. In field experiments, we set up three irrigation levels (irrigation water quotas of 22.5, 30, and 37.5 mm, respectively, for W₁, W₂, and W₃), two nitrogen application levels (77.5 and 110 kg·ha⁻¹, recorded as N₁ and N₂), and a control treatment (W₂N₀) that did not include the application of nitrogen. The results showed that nitrogen application enhanced the growth, physiological indexes, yield, and water use efficiency of the W₁, W₂, and W₃ treatments when the irrigation volume remained the same. In comparison with no nitrogen application (W₂N₀), the peanut growth, physiological indexes, yield, and water use efficiency improved with increasing irrigation amounts in the N₁ and N₂ treatments. With an increase in the irrigation volume, the water use efficiency grew; the W₃N₂ treatment had the highest water use efficiency, which was 1.32 kg·m⁻³. The total water consumption and reproductive-stage water consumption of the peanuts in all treatments increased with the irrigation volume, and a high yield was achieved at 402.57 mm, which was 5.2974 Mg·ha⁻¹. In the W₁, W₂, and W₃ treatments, the nitrogen partial factor productivity significantly decreased as the nitrogen application increased, with the nitrogen partial factor productivity in the W₃N₁ treatment being the highest, at 60.61 kg·kg⁻¹. A comprehensive evaluation based on principal component analysis assigned W₃N₂ the higher score. These findings suggest that irrigation water quotas of 37.5 mm should be coupled with 110 kg·ha⁻¹ nitrogen applications for peanuts using drip irrigation in mulch film in Xinjiang. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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15 pages, 1613 KiB

Open AccessArticle

Pre-Harvest Salicylic Acid Application Affects Fruit Quality and Yield under Deficit Irrigation in Aristotelia chilensis (Mol.) Plants

by Jorge González-Villagra, León A. Bravo, Marjorie Reyes-Díaz, Jerry D. Cohen, Alejandra Ribera-Fonseca, Rafael López-Olivari, Emilio Jorquera-Fontena and Ricardo Tighe-Neira

Plants 2023, 12(18), 3279; https://doi.org/10.3390/plants12183279 - 15 Sep 2023

Cited by 1 | Viewed by 1181

Abstract

Salicylic acid (SA) application is a promising agronomic tool. However, studies under field conditions are required, to confirm the potential benefits of SA. Thus, SA application was evaluated under field conditions for its effect on abscisic acid levels, antioxidant related-parameters, fruit quality, and [...] Read more.

Salicylic acid (SA) application is a promising agronomic tool. However, studies under field conditions are required, to confirm the potential benefits of SA. Thus, SA application was evaluated under field conditions for its effect on abscisic acid levels, antioxidant related-parameters, fruit quality, and yield in Aristotelia chilensis subjected to different levels of irrigation. During two growing seasons, three-year-old plants under field conditions were subjected to full irrigation (FI: 100% of reference evapotranspiration (ETo), and deficit irrigation (DI: 60% ETo). During each growth season, a single application of 0.5 mM SA was performed at fruit color change by spraying fruits and leaves of both irrigation treatments. The results showed that DI plants experienced moderate water stress (−1.3 MPa), which increased ABA levels and oxidative stress in the leaves. The SA application facilitated the recovery of all physiological parameters under the DI condition, increasing fruit fresh weight by 44%, with a 27% increase in fruit dry weight, a 1 mm increase in equatorial diameter, a 27% improvement in yield per plant and a 27% increase in total yield, with lesser oxidative stress and tissue ABA levels in leaves. Also, SA application significantly increased (by about 10%) the values of fruit trait variables such as soluble solids, total phenols, and antioxidant activity, with the exceptions of titratable acidity and total anthocyanins, which did not vary. The results demonstrated that SA application might be used as an agronomic strategy to improve fruit yield and quality, representing a saving of 40% regarding water use. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Figure 1
Daily values for maximum (Tmax) and minimum (Tmin) temperature, reference evapotranspiration (ETo), and rainfall during both evaluated seasons. The figures (A,B) correspond to the 2020/2021 season; the figures (C,D) correspond to the 2021/2022 season. Full article ">Figure 2
Abscisic acid (ABA) levels in leaves of A. chilensis plants subjected to two irrigation treatments (full irrigation (FI) (100% ETo) and deficit irrigation (DI) (60% ETo)) and two SA doses (0 and 0.5 mM) during the two seasons. Different uppercase letters indicate significant differences between SA applications for the same irrigation treatment and season according to Student’s t test (p ≤ 0.05). Different lowercase letters indicate significant differences between irrigation treatments for the same SA application and season according to Student’s t test (p ≤ 0.05). The bars are means ± SE (n = 9). Full article ">Figure 3
Lipid peroxidation in leaves of A. chilensis plants subjected to two irrigation treatments (full irrigation (FI) (100% ETo) and deficit irrigation (DI) (60% ETo)) and two SA doses (0 and 0.5 mM) during two seasons. Different uppercase letters indicate significant differences between SA applications for the same irrigation treatment and season according to Student’s t test (p ≤ 0.05). Different lowercase letters indicate significant differences between irrigation treatments for the same SA application and season according to Student’s t test (p ≤ 0.05). The bars are means ± SE (n = 9). Full article ">Figure 4
Antioxidant activity (A), total phenol content (B), and total anthocyanins (C) in fruits of A. chilensis plants subjected to two irrigation treatments (full irrigation (FI) (100% ETo) and deficit irrigation (DI) (60% ETo)) and two SA doses (0 and 0.5 mM) during two evaluated seasons. Different uppercase letters indicate significant differences between SA applications for the same irrigation treatment according to Student’s t test (p ≤ 0.05). Different lowercase letters indicate significant differences between irrigation treatments for the same SA application according to Student’s t test (p ≤ 0.05). The bars are means ± SE (n = 9). Full article ">

14 pages, 11066 KiB

Open AccessArticle

Physiological Mechanism of Waterlogging Stress on Yield of Waxy Maize at the Jointing Stage

by Xuepeng Zhang, Chao Huang, Ye Meng, Xuchen Liu, Yang Gao, Zhandong Liu and Shoutian Ma

Plants 2023, 12(17), 3034; https://doi.org/10.3390/plants12173034 - 23 Aug 2023

Cited by 3 | Viewed by 1922

Abstract

In the main agricultural area for waxy maize production in China, waterlogging occurs frequently during the waxy maize jointing stage, and this causes significant yield reduction. It is very important to understand the physiological mechanism of waterlogging stress in waxy maize during the [...] Read more.

In the main agricultural area for waxy maize production in China, waterlogging occurs frequently during the waxy maize jointing stage, and this causes significant yield reduction. It is very important to understand the physiological mechanism of waterlogging stress in waxy maize during the jointing stage to develop strategies against waterlogging stress. Therefore, this study set waterlogging treatments in the field for 0, 2, 4, 6, 8, and 10 days during the waxy maize jointing stage, and were labelled CK, WS2, WS4, WS6, WS8 and WS10, respectively. By analyzing the effect of waterlogging on the source, sink, and transport of photoassimilates, the physiological mechanism of waterlogging stress in the jointing stage was clarified. The results show that PEPC and POD activities and Pro content decreased significantly under WS2 compared to CK. Except for these three indicators, the Pn, GS, leaf area, kernel number, yield, and puncture strength of stems were significantly decreased under the WS4. Under the WS6, the content of MDA began to increase significantly, while almost all other physiological indices decreased significantly. Moreover, the structure of stem epidermal cells and the vascular bundle were deformed after 6 days of waterlogging. Therefore, the threshold value of waterlogging stress occured at 4 to 6 days in the jointing stage of waxy maize. Moreover, waterlogging stress at the jointing stage mainly reduces the yield by reducing the number of kernels; specifically, the kernel number decreased by 6.7–15.5% in 4–10 days of waterlogging, resulting in a decrease of 9.9–20.2% in the final yield. Thus, we have shown that waterlogging stress at the jointing stage results in the decrease of potential waxy maize kernel numbers and yield when the synthesis of sources was limited and the transport of photoassimilates was restricted. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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14 pages, 1552 KiB

Open AccessArticle

Effect of Hydrogen Peroxide Application on Salt Stress Mitigation in Bell Pepper (Capsicum annuum L.)

by Jéssica Aragão, Geovani Soares de Lima, Vera Lúcia Antunes de Lima, André Alisson Rodrigues da Silva, Jessica Dayanne Capitulino, Edmilson Júnio Medeiros Caetano, Francisco de Assis da Silva, Lauriane Almeida dos Anjos Soares, Pedro Dantas Fernandes, Maria Sallydelândia Sobral de Farias, Hans Raj Gheyi, Lucyelly Dâmela Araújo Borborema, Thiago Filipe de Lima Arruda and Larissa Fernanda Souza Santos

Plants 2023, 12(16), 2981; https://doi.org/10.3390/plants12162981 - 18 Aug 2023

Cited by 4 | Viewed by 1886

Abstract

The present study aimed to evaluate the effects of the foliar application of hydrogen peroxide on the attenuation of salt stress on the growth, photochemical efficiency, production and water use efficiency of ‘All Big’ bell pepper plants. The experiment was conducted under greenhouse [...] Read more.

The present study aimed to evaluate the effects of the foliar application of hydrogen peroxide on the attenuation of salt stress on the growth, photochemical efficiency, production and water use efficiency of ‘All Big’ bell pepper plants. The experiment was conducted under greenhouse conditions in Campina Grande, PB, Brazil. Treatments were distributed in a randomized block design, in a 5 × 5 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water (0.8, 1.2, 2.0, 2.6 and 3.2 dS m⁻¹) and five concentrations of hydrogen peroxide (0, 15, 30, 45 and 60 μM), with three replicates. Foliar application of hydrogen peroxide at concentration of 15 μM attenuated the deleterious effects of salt stress on photochemical efficiency, biomass accumulation and production components of bell pepper plants irrigated using water with an electrical conductivity of up to 3.2 dS m⁻¹. Foliar spraying of hydrogen peroxide at a concentration of 60 μM intensified the effects of salt stress. The ‘All Big’ bell pepper was classified as moderately sensitive to salt stress, with an irrigation water salinity threshold of 1.43 dS m⁻¹ and a unit decrease of 8.25% above this salinity level. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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22 pages, 8276 KiB

Open AccessEditor’s ChoiceArticle

Salicylic Acid as a Salt Stress Mitigator on Chlorophyll Fluorescence, Photosynthetic Pigments, and Growth of Precocious-Dwarf Cashew in the Post-Grafting Phase

by Thiago Filipe de Lima Arruda, Geovani Soares de Lima, André Alisson Rodrigues da Silva, Carlos Alberto Vieira de Azevedo, Allesson Ramos de Souza, Lauriane Almeida dos Anjos Soares, Hans Raj Gheyi, Vera Lúcia Antunes de Lima, Pedro Dantas Fernandes, Francisco de Assis da Silva, Mirandy dos Santos Dias, Lucia Helena Garófalo Chaves and Luciano Marcelo Fallé Saboya

Plants 2023, 12(15), 2783; https://doi.org/10.3390/plants12152783 - 27 Jul 2023

Cited by 9 | Viewed by 1613

Abstract

Salicylic acid is a phytohormone that has been used to mitigate the effects of saline stress on plants. In this context, the objective was to evaluate the effect of salicylic acid as a salt stress attenuator on the physiology and growth of precocious-dwarf [...] Read more.

Salicylic acid is a phytohormone that has been used to mitigate the effects of saline stress on plants. In this context, the objective was to evaluate the effect of salicylic acid as a salt stress attenuator on the physiology and growth of precocious-dwarf cashew plants in the post-grafting phase. The study was carried out in a plant nursery using a randomized block design in a 5 × 4 factorial arrangement corresponding to five electrical conductivity levels of irrigation water (0.4, 1.2, 2.0, 2.8, and 3.6 dS m⁻¹) and four salicylic acid concentrations (0, 1.0, 2.0, and 3.0 mM), with three replications. Irrigation water with electrical conductivity levels above 0.4 dS m⁻¹ negatively affected the relative water content in the leaf blade, photosynthetic pigments, the fluorescence of chlorophyll a, and plant growth and increased electrolyte leakage in the leaf blade of precocious-dwarf cashew plants in the absence of salicylic acid. It was verified through the regression analysis that salicylic acid at a concentration of 1.1 mM attenuated the effects of salt stress on the relative water content and electrolyte leakage in the leaf blade, while the concentration of 1.7 mM increased the synthesis of photosynthetic pigments in precocious-dwarf cashew plants. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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13 pages, 453 KiB

Open AccessArticle

Growth and Performance of Guar (Cyamopsis tetragonoloba (L.) Taub.) Genotypes under Various Irrigation Regimes with and without Biogenic Silica Amendment in Arid Southwest US

by Alonso Garcia, Kulbhushan Grover, Dawn VanLeeuwen, Blair Stringam and Brian Schutte

Plants 2023, 12(13), 2486; https://doi.org/10.3390/plants12132486 - 29 Jun 2023

Cited by 6 | Viewed by 1742

Abstract

Guar is a potential crop that can be grown as a forage or as a seed crop in arid to semi-arid regions due to its low water requirements and tolerance to heat. Optimizing irrigation water use is important for making alternative crops such [...] Read more.

Guar is a potential crop that can be grown as a forage or as a seed crop in arid to semi-arid regions due to its low water requirements and tolerance to heat. Optimizing irrigation water use is important for making alternative crops such as guar a sustainable option. Amendments such as biogenic silica, a sedimentary rock from a biogenic source such as fossils, may help plants tolerate water stress due to reduced irrigation. The objective of the current study was to evaluate seed yield and attribute components and agronomic and physiological parameters for four guar genotypes (Matador, Kinman, Lewis, and NMSU 15-G1) under five drip irrigation regimes (I₁-normal irrigation, I₂-no irrigation at 75% pod formation, I₃-no irrigation at 50% and 75% pod formation, I₄-terminate irrigation at flowering, and I₅-terminate irrigation at flowering + biogenic silica amendment) at Las Cruces in southern New Mexico, USA, from 2016 to 2018. On average, the I₁ irrigation regime produced the highest guar seed yield (2715 kg ha⁻¹) followed by I₅ (2469 kg ha⁻¹) from 2016 to 2018. As compared to the I₁ regime, the I₂ and I₃ regimes resulted in a 20.8% and 23.4% decline in guar seed yield, respectively, on average from 2016 to 2018. The results suggest that the addition of biogenic silica might help to improve guar seed yield under reduced irrigation conditions and can produce comparable yields with an average of 300 mm of irrigation during the growing season in the southern New Mexico region of the Southwest US. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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14 pages, 2131 KiB

Open AccessArticle

The Effects of Foliar Supplementation of Silicon on Physiological and Biochemical Responses of Winter Wheat to Drought Stress during Different Growth Stages

by Dongfeng Ning, Yingying Zhang, Xiaojing Li, Anzhen Qin, Chao Huang, Yuanyuan Fu, Yang Gao and Aiwang Duan

Plants 2023, 12(12), 2386; https://doi.org/10.3390/plants12122386 - 20 Jun 2023

Cited by 13 | Viewed by 2201

Abstract

Drought is one of the major environmental stresses, resulting in serious yield reductions in wheat production. Silicon (Si) has been considered beneficial to enhancing wheat resistance to drought stress. However, few studies have explored the mediated effects of foliar supplementation of Si on [...] Read more.

Drought is one of the major environmental stresses, resulting in serious yield reductions in wheat production. Silicon (Si) has been considered beneficial to enhancing wheat resistance to drought stress. However, few studies have explored the mediated effects of foliar supplementation of Si on drought stress imposed at different wheat growth stages. Therefore, a field experiment was carried out to investigate the effects of Si supplementation on the physiological and biochemical responses of wheat to drought stress imposed at the jointing (D-jointing), anthesis (D-anthesis) and filling (D-filling) stages. Our results showed that a moderate water deficit markedly decreased the dry matter accumulation, leaf relative water content (LRWC), photosynthetic rate (Pn), stomatal conductance (Sc), transpiration rate (Tr) and antioxidant activity [peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT)]. On the contrary, it remarkably increased the content of osmolytes (proline, soluble sugar, soluble protein) and lipid peroxidation. The grain yields of D-jointing, D-anthesis and D-filling treatments were 9.59%, 13.9% and 18.9% lower, respectively, compared to the control treatment (CK). However, foliar supplementation of Si at the anthesis and filling stages significantly improved plant growth under drought stress due to the increased Si content. Consequently, the improvement in antioxidant activity and soluble sugar, and the reduction in the content of ROS, increased the LRWC, chlorophyll content, Pn, Sc and Tr, and ultimately boosted wheat yield by 5.71% and 8.9%, respectively, in comparison with the non-Si-treated plants subjected to water stress at the anthesis and filling stages. However, the mitigating effect of Si application was not significant at the jointing stage. It was concluded that foliar supplementation of Si, especially at the reproductive stage, was effective in alleviating drought-induced yield reduction. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Effect of foliar application of Si fertilizer on leaf relative water content (A) and dry matter (B) of wheat at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, drought stress; CK, normal irrigation throughout all stages. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 2
Effect of foliar application of Si fertilizer on photosynthetic rate (A), stomatal conductance (B) and transpiration (C) of wheat at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, moderate drought stress; CK, normal irrigation throughout all stages. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 3
Effect of foliar application of Si fertilizer on chlorophyll a (A) and chlorophyll b (B) content in wheat leaves at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, drought stress; CK, well-watered control conditions throughout all stages. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 4
Effect of foliar application of Si fertilizer on proline (A), soluble protein (B) and soluble sugar content (C) in wheat leaves at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, drought stress; CK, well-watered controls condition. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 5
Effect of foliar application of Si fertilizer on malondialdehyde (MDA) (A) and superoxide radical (O2·−) content (B) in wheat leaves at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, drought stress; CK, well-watered controls condition. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 6
Effect of foliar application of Si fertilizer on superoxide dismutase (SOD) (A), peroxidase (POD) (B) and catalase (CAT) (C) activities content in wheat leaves at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, drought stress; CK, well-watered controls condition. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 7
Effect of foliar application of Si fertilizer on Si concentration in wheat leaves (A) and soil (B) at jointing, anthesis and filling stages under drought and normal conditions. +Si, Si addition; -Si, no Si addition; D, drought stress; CK, well-watered controls condition. Data are the means ± standard deviation (SD) of three replicates. Different letters (a, b, c) above the bars indicate statistical significance (p ≤ 0.05). Full article ">Figure 8
Pearson correlation analysis among yield and selected growth and physiological parameters measured at different growth stages. Red and blue represent positive and negative correlations, respectively. The deeper the color, the smaller the shape and the stronger the correlations. RWC, relative water content; Pn, photosynthetic rate; Tr, transpiration; Gs, stomatal conductance; Chla, chlorophyll a; Chlb, chlorophyll b; SS, soluble sugar; SP, soluble protein; DM, dry matter; HI, harvest index. * Significant at p ≤ 0.05. Full article ">

18 pages, 983 KiB

Open AccessArticle

Irrigation Management Strategies to Enhance Forage Yield, Feed Value, and Water-Use Efficiency of Sorghum Cultivars

by Amir Ghalkhani, Farid Golzardi, Azim Khazaei, Ali Mahrokh, Árpád Illés, Csaba Bojtor, Seyed Mohammad Nasir Mousavi and Adrienn Széles

Plants 2023, 12(11), 2154; https://doi.org/10.3390/plants12112154 - 30 May 2023

Cited by 9 | Viewed by 2764

Abstract

Water scarcity is a major obstacle to forage crop production in arid and semi-arid regions. In order to improve food security in these areas, it is imperative to employ suitable irrigation management techniques and identify drought-tolerant cultivars. A 2-year field experiment (2019–2020) was [...] Read more.

Water scarcity is a major obstacle to forage crop production in arid and semi-arid regions. In order to improve food security in these areas, it is imperative to employ suitable irrigation management techniques and identify drought-tolerant cultivars. A 2-year field experiment (2019–2020) was conducted in a semi-arid region of Iran to assess the impact of different irrigation methods and water deficit stress on forage sorghum cultivars’ yield, quality, and irrigation water-use efficiency (IWUE). The experiment involved two irrigation methods, i.e., drip (DRIP) and furrow (FURW), and three irrigation regimes supplied 100% (I₁₀₀), 75% (I₇₅), and 50% (I₅₀) of the soil moisture deficit. In addition, two forage sorghum cultivars (hybrid Speedfeed and open-pollinated cultivar Pegah) were evaluated. This study revealed that the highest dry matter yield (27.24 Mg ha⁻¹) was obtained under I₁₀₀ × DRIP, whereas the maximum relative feed value (98.63%) was achieved under I₅₀ × FURW. Using DRIP resulted in higher forage yield and IWUE compared to FURW, and the superiority of DRIP over FURW increased with the severity of the water deficit. The principal component analysis indicated that, as drought stress severity increased across all irrigation methods and cultivars, forage yield decreased, while quality increased. Plant height and leaf-to-stem ratio were found to be suitable indicators for comparing forage yield and quality, respectively, and they showed a negative correlation between the quality and quantity of forage. DRIP improved forage quality under I₁₀₀ and I₇₅, while FURW exhibited a better feed value under the I₅₀ regime. Altogether, in order to achieve the best possible forage yield and quality while minimizing water usage, it is recommended to grow the Pegah cultivar and compensate for 75% of soil moisture deficiency using drip irrigation. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Effects of irrigation method × irrigation regime × cultivar on the crude protein content of sorghum. I100, I75, and I50, supplying 100%, 75%, and 50% of the soil moisture deficit, respectively. Different letters above the bars (means of replicates ± SE) indicate significant differences from each other at p < 0.05. Full article ">Figure 2
Effects of irrigation method × irrigation regime × cultivar on the organic matter digestibility of sorghum. I100, I75, and I50, supplying 100%, 75%, and 50% of the soil moisture deficit, respectively. Different letters above the bars (means of replicates ± SE) indicate significant differences from each other at p < 0.05. Full article ">Figure 3
Principal component analysis (PCA) of the first two components performed on the forage yield and quality, and water-use efficiency of sorghum affected by irrigation method, irrigation regime, and cultivar; S: Speedfeed, P: Pegah, 1: Furrow + I100, 2: Furrow + I75, 3: Furrow + I50, 4: Drip + I100, 5: Drip + I75, 6: Drip + I50. GHY, green herbage yield; DMY, dry matter yield; IWUE, irrigation water-use efficiency; PLH, plant height; L:S, leaf-to-stem ratio; CPY, crude protein yield; DDMY, digestible dry matter yield; CPC, crude protein content; ADF, acid detergent fiber; NDF, neutral detergent fiber; DMD, dry matter digestibility; OMD, organic matter digestibility; DMI, dry matter intake; RFV, relative feed value; ME, metabolizable energy; NEL, net energy for lactation. Full article ">

32 pages, 7731 KiB

Open AccessEditor’s ChoiceArticle

Foliar Applications of Salicylic Acid on Boosting Salt Stress Tolerance in Sour Passion Fruit in Two Cropping Cycles

by Thiago Galvão Sobrinho, André Alisson Rodrigues da Silva, Geovani Soares de Lima, Vera Lúcia Antunes de Lima, Vitória Ediclécia Borges, Kheila Gomes Nunes, Lauriane Almeida dos Anjos Soares, Luciano Marcelo Fallé Saboya, Hans Raj Gheyi, Josivanda Palmeira Gomes, Pedro Dantas Fernandes and Carlos Alberto Vieira de Azevedo

Plants 2023, 12(10), 2023; https://doi.org/10.3390/plants12102023 - 18 May 2023

Cited by 11 | Viewed by 2430

Abstract

Brazil stands out as the largest producer of sour passion fruit; however, the water available for irrigation is mostly saline, which can limit its cultivation. This study was carried out with the objective of evaluating the effects of salicylic acid in the induction [...] Read more.

Brazil stands out as the largest producer of sour passion fruit; however, the water available for irrigation is mostly saline, which can limit its cultivation. This study was carried out with the objective of evaluating the effects of salicylic acid in the induction of tolerance in sour passion fruit to salt stress. The assay was conducted in a protected environment, using a completely randomized design in a split-plot scheme, with the levels of electrical conductivity of the irrigation water (0.8, 1.6, 2.4, 3.2, and 4.0 dS m⁻¹) considering the plots and concentrations of salicylic acid (0, 1.2, 2.4, and 3.6 mM) the subplots, with three replications. The physiological indices, production components, and postharvest quality of sour passion fruit were negatively affected by the increase in the electrical conductivity of irrigation water, and the effects of salt stress were intensified in the second cycle. In the first cycle, the foliar application of salicylic acid at concentrations between 1.0 and 1.4 mM partially reduced the harmful effects of salt stress on the relative water content of leaves, electrolyte leakage, gas exchange, and synthesis of photosynthetic pigments, in addition to promoting an increase in the yield and quality parameters of sour passion fruit. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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18 pages, 2549 KiB

Open AccessArticle

Photosynthesis Product Allocation and Yield in Sweet Potato in Response to Different Late-Season Irrigation Levels

by Mingjing Zhou, Yiming Sun, Shaoxia Wang, Qing Liu and Huan Li

Plants 2023, 12(9), 1780; https://doi.org/10.3390/plants12091780 - 26 Apr 2023

Cited by 3 | Viewed by 2261

Abstract

Soil water deficit is an important factor affecting the source–sink balance of sweet potato during its late-season growth, but water regulation during this period has not been well studied. Therefore, the aim of this study was to determine the appropriate irrigation level in [...] Read more.

Soil water deficit is an important factor affecting the source–sink balance of sweet potato during its late-season growth, but water regulation during this period has not been well studied. Therefore, the aim of this study was to determine the appropriate irrigation level in late-season sweet potato, and the effect of irrigation level on accumulation and allocation of photosynthetic products. In this study, two yield-based field trials (2021–2022) were conducted in which five late-season irrigation levels set according to the crop evapotranspiration rate were tested (T₀: non-irrigation, T₁: 33% ET_c, T₂: 75% ET_c, T₃: 100% ET_c, T₄: 125% ET_c). The effects of the different irrigation levels on photosynthetic physiological indexes, ¹³C transfer allocation, water use efficiency (WUE), water productivity (WP), and the yield and economic benefit of sweet potato were studied. The results showed that late-season irrigation significantly increased the total chlorophyll content and net photosynthetic rate of functional leaves, in addition to promoting the accumulation of above-ground-source organic biomass (p < 0.05). The rate of ¹³C allocation, maximum accumulation rate (V_max), and average accumulation rate (V_mean) of dry matter in storage root were significantly higher under T₂ irrigation than under the other treatments (p < 0.05). This suggests that both non-irrigation (T₀) and over-irrigation (T₄) were not conducive to the transfer and allocation of photosynthetic products to storage roots in late-season sweet potato. However, moderate irrigation (T₂) effectively promoted the source–sink balance, enhanced the source photosynthetic rate and stimulated the sink activity, such that more photosynthate was allocated to the storage sink. The results also showed that T₂ irrigation treatments significantly increased yield, WUE and WP compared to T₀ and T₄ (p < 0.05), suggesting that moderate irrigation (T₂) can significantly promote the potential of storage root production and field productivity. There was a close relationship between economic benefit and marketable sweet potato yield, and both were highest under T₂ (p < 0.05), increasing by 36.1% and 59.9% compared with T₀ over the two-year study period. In conclusion, irrigation of late-season sweet potato with 75% evapotranspiration (T₂) can improve both the yield and production potential. Together, these results support the use of late-season water management in the production of sweet potato. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Dynamic effects of irrigation levels (T0–T4) on chlorophyll a content (A,D), chlorophyll b content (B,E) and total chlorophyll (a + b) (C,F) during late-season sweet potato growth in 2021 (A–C) and 2022 (D–F). S1–S3 represent 124, 134, and 144 days after transplantation, respectively. Full article ">Figure 2
Effects of irrigation levels (T0–T4) on the photosynthetic parameters of sweet potato during its late-season growth. Intercellular carbon dioxide concentration (A), net photosynthetic rate (B), transpiration rate (C) and stomatal conductance (D). Different lowercase letters in the same period indicate a significant difference (p < 0.05); the same letter indicates no significant difference (p < 0.05). Full article ">Figure 3
Effects of irrigation levels (T0–T4) on 13C accumulation (A) and the 13C allocation rate (B) in the shoots and storage roots of sweet potato in 2021 and 2022. Different lowercase letters in the same period indicate a significant difference (p < 0.05); the same letter indicates no significant difference (p < 0.05). Full article ">Figure 4
Redundancy analysis of irrigation level, yield, net profit, 13C accumulation and the 13C allocation rate in sweet potato shoots and storage roots based on a logistics function. (A) Data for the year 2021: axis 1, 76.69%; axis 2, 21.31%. (B) Data for the year 2022: axis 1, 94.71%; axis 2, 4.78%. Full article ">Figure 5
Precipitation and reference evapotranspiration during the whole sweet potato growth period, as determined in the study area from 2021 to 2022. The two red boxes represent rainfall and reference evapotranspiration during the 2021 and 2022 trials, respectively. Full article ">

18 pages, 5686 KiB

Open AccessArticle

Irrigation Scheduling for Maize under Different Hydrological Years in Heilongjiang Province, China

by Tangzhe Nie, Zhenping Gong, Zhongxue Zhang, Tianyi Wang, Nan Sun, Yi Tang, Peng Chen, Tiecheng Li, Shuai Yin, Mengmeng Zhang and Siwen Jiang

Plants 2023, 12(8), 1676; https://doi.org/10.3390/plants12081676 - 17 Apr 2023

Cited by 4 | Viewed by 2037

Abstract

Appropriate irrigation schedules could minimize the existing imbalance between agricultural water supply and crop water requirements (ET_c), which is severely impacted by climate change. In this study, different hydrological years (a wet year, normal year, dry year, and an extremely [...] Read more.

Appropriate irrigation schedules could minimize the existing imbalance between agricultural water supply and crop water requirements (ET_c), which is severely impacted by climate change. In this study, different hydrological years (a wet year, normal year, dry year, and an extremely dry year) in Heilongjiang Province were calculated by hydrological frequency methods. Then, the single crop coefficient method was used to calculate the maize ET_c, based on the daily meteorological data of 26 meteorological stations in Heilongjiang Province from 1960 to 2020. Afterward, the CROPWAT model was used to calculate the effective precipitation (P_e) and irrigation water requirement (Ir), and formulate the irrigation schedules of maize in Heilongjiang Province under different hydrological years. The results showed that ET_c and Ir decreased first and then increased from west to east. The P_e and crop water surplus deficit index increased first and then decreased from west to east in Heilongjiang Province. Meanwhile, the average values of the Ir in were 171.14 mm, 232.79 mm, 279.08 mm, and 334.47 mm in the wet year, normal year, dry year, and extremely dry year, respectively. Heilongjiang Province was divided into four irrigation zones according to the Ir of different hydrological years. Last, the irrigation quotas for the wet year, normal year, dry year, and extremely dry year were 0~180 mm, 20~240 mm, 60~300 mm, and 80~430 mm, respectively. This study provides reliable support for maize irrigation practices in Heilongjiang Province, China. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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22 pages, 3947 KiB

Open AccessArticle

Effect of Long-Term Semiarid Pasture Management on Soil Hydraulic and Thermal Properties

by Geeta Kharel, Madhav Dhakal, Sanjit K. Deb, Lindsey C. Slaughter, Catherine Simpson and Charles P. West

Plants 2023, 12(7), 1491; https://doi.org/10.3390/plants12071491 - 29 Mar 2023

Cited by 4 | Viewed by 2039

Abstract

Semiarid pasture management strategies can affect soil hydraulic and thermal properties that determine water fluxes and storage, and heat flow in unsaturated soils. We evaluated long-term (>10 years) perennial and annual semiarid pasture system effects on saturated hydraulic conductivity (k_s), [...] Read more.

Semiarid pasture management strategies can affect soil hydraulic and thermal properties that determine water fluxes and storage, and heat flow in unsaturated soils. We evaluated long-term (>10 years) perennial and annual semiarid pasture system effects on saturated hydraulic conductivity (k_s), soil water retention curves (SWRCs), soil water thresholds (i.e., volumetric water content (θ_v) at saturation, field capacity (FC), and permanent wilting point (PWP); plant available water (PAW)), thermal conductivity (λ), and diffusivity (D_t) within the 0–20 cm soil depth. Forage systems included: Old World bluestem (Bothriochloa bladhii) + legumes (predominantly alfalfa (Medicago sativa)) (OWB-legume), native grass-mix (native), alfalfa + tall wheatgrass (Thinopyrum ponticum) (alfalfa-TW), and annual grass-mix (annual) pastures on a clay loam soil; and native, teff (Eragrostis tef), OWB-grazed, and OWB-ungrazed pastures on a sandy clay loam soil. The perennial OWB-legume and native pastures had increased soil organic matter (SOM) and reduced bulk density (ρ_b), improving k_s, soil water thresholds, λ, and D_t, compared to annual teff and alfalfa-TW (P < 0.05). Soil λ, but not D_t, increased with increasing θ_v. Grazed pastures decreased k_s and water retention compared to other treatments (P < 0.05), yet did not affect λ and D_t (P > 0.05), likely due to higher ρ_b and contact between particles. Greater λ and D_t at saturation and PWP in perennial versus annual pastures may be attributed to differing SOM and ρ_b, and some a priori differences in soil texture. Overall, our results suggest that perennial pasture systems are more beneficial than annual systems for soil water storage and heat movement in semiarid regions. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Figure 1
Monthly precipitation and maximum and minimum air temperatures from January 2016 to December 2017 at the study site, New Deal, TX, USA. The red color line represents long-term (1911–2008) monthly average precipitation for the study area. Full article ">Figure 2
Forage crops grown in the experimental treatment plots during the 2016–2017 growing season at New Deal, TX, USA (not drawn to scale). The cultivar of Old-World bluestem (OWB) was WW-B. Dahl. Triangles in the west native grass-mix pasture represent soil sampling locations as an example for all other pastures. Full article ">Figure 3
Saturated hydraulic conductivity (ks) at soil depths (D) of 0–10 and 10–20 cm for Old-World bluestem (OWB)-legume, alfalfa-tall wheatgrass (TW), native, and annual treatments (Trt.) in the east pasture area; and native, OWB-grazed, OWB-ungrazed, and teff in the west pasture area. Data were averaged across years (Yr 2016 and 2017), sampling locations, and replicates. LSD (least significant difference), represented by vertical line with the asterisk (*), is considered significant at α = 0.05; ns, LSD (vertical line without the asterisk) is nonsignificant at α = 0.05; §, P value of the interaction. Full article ">Figure 4
Measured (symbols) and fitted (lines) van Genuchten soil water retention curves (SWRCs) at 0–5, 5–10, 10–15, and 15–20 cm soil depths for all treatments in the east and west pasture area during a 2-year study period (2016–2017). Measured data represent average value across sampling points, replicates, and years, whereas fitted line was obtained using all sample replicates. OWB, Old-World bluestem; TW, tall wheatgrass. Full article ">Figure 5
Measured soil thermal conductivity λ (red symbols) and thermal diffusivity Dt (green symbols) as a function of volumetric water contents (θv) corresponding to different applied pressure heads (i.e., 0, −100, −330, −500, −2000, −3000, −5000, −10,000, and −15,000 cm, as shown in <a href="#plants-12-01491-f004" class="html-fig">Figure 4</a>) at soil depths of 0–5, 5–10, 10–15, and 15–20 cm for all treatments in the east and west pasture area during a 2-year study period (2016–2017). Data were averaged across sampling points, replicates, and years. OWB, Old-World bluestem; TW, tall wheatgrass. Full article ">Figure 6
Relationship between soil thermal conductivity (λ) and volumetric water content (θv) within the 0–20 cm soil depth for all pasture treatments in the east (solid line) and west (dashed line) area during a 2-year study period (2016–2017). The θv is a function of applied pressure heads given by measured soil water retention curves (SWRCs) (<a href="#plants-12-01491-f004" class="html-fig">Figure 4</a>). Data pooled from years, depths, and pressure heads applied for determining SWRCs. Full article ">

15 pages, 2939 KiB

Open AccessArticle

Artificial Grassland Had Higher Water Use Efficiency in Year with Less Precipitation in the Agro-Pastoral Ecotone

by Kun Zhao, Yan Qu, Deping Wang, Zhongkuan Liu and Yuping Rong

Plants 2023, 12(6), 1239; https://doi.org/10.3390/plants12061239 - 9 Mar 2023

Viewed by 1988

Abstract

Improving plant water use efficiency is a key strategy for the utilization of regional limited water resources as well as the sustainable development of agriculture industry. To investigate the effects of different land use types on plant water use efficiency and their mechanisms, [...] Read more.

Improving plant water use efficiency is a key strategy for the utilization of regional limited water resources as well as the sustainable development of agriculture industry. To investigate the effects of different land use types on plant water use efficiency and their mechanisms, a randomized block experiment was designed in the agro-pastoral ecotone of northern China during 2020–2021. The differences in dry matter accumulation, evapotranspiration, soil physical and chemical properties, soil water storage and water use efficiency and their relationships among cropland, natural grassland and artificial grassland were studied. The results show that: In 2020, the dry matter accumulation and water use efficiency of cropland were significantly higher than those of artificial and natural grassland. In 2021, dry matter accumulation and water use efficiency of artificial grassland increased significantly from 364.79 g·m⁻² and 24.92 kg·ha⁻¹·mm⁻¹ to 1037.14 g·m⁻² and 50.82 kg·ha⁻¹·mm⁻¹, respectively, which were significantly higher than cropland and natural grassland. The evapotranspiration of three land use types showed an increasing trend in two years. The main reason affecting the difference of water use efficiency was that land use type affected soil moisture and soil nutrients, and then changed the dry matter accumulation and evapotranspiration of plants. During the study period, the water use efficiency of artificial grassland was higher in years with less precipitation. Therefore, expanding the planted area of artificial grassland may be one of the effective ways to promote the full utilization of regional water resources. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Soil volumetric water content at 0–10 cm, 10–20 cm, and 20–30 cm soil layers of different land use types in 2020 (a) and 2021 (b). AG: artificial grassland, AL: cropland, NG: natural grassland, T: land use type, L: soil layer, T × L: interaction of land use type and soil layer. Lowercase letters indicate significant differences between soil depths in the same treatment, and uppercase letters indicate significant differences between land use types (p < 0.05). ns, **, *** represent p > 0.05, p < 0.01, p < 0.001, respectively. Data are shown as mean ± s.e.m. Full article ">Figure 2
Dry matter accumulation between land use types in 2020 and 2021. AG: artificial grassland; AL: cropland; NG: natural grassland; T: land use type; Y: year; T × Y: interaction of land use type and year. Lowercase letters indicate the significant difference of dry matter accumulation among different land use types in the same year (p < 0.05). The asterisk indicates a significant difference between two years for the same land use type. *, ***, ns represent p < 0.05, p < 0.001, p > 0.05, respectively. Data are shown as mean ± s.e.m. Full article ">Figure 3
Water use efficiency of different land use types in 2020 and 2021. AG: artificial grassland; AL: cropland; NG: natural grassland; T: land use type; Y: year; T × Y: interaction of land use type and year. Lowercase letters indicate the significant difference between different land use type in the same year (p < 0.05). The asterisk indicates a significant difference between two years for the same land use type. *, ***, ns represent p < 0.05, p < 0.001, p > 0.05, respectively. Data are shown as mean ± s.e.m. Full article ">Figure 4
Structural Equation Model (SEM) describing the effect of land use types and environmental factors on water use efficiency. (a) Path analysis of influencing factors of water use efficiency, (b) standardized total effects of factors affecting water use efficiency. (c) Standardized direct effects of factors affecting water use efficiency. (d) Standardized indirect effects of factors affecting water use efficiency. Numbers adjacent to arrows are indicative of the effect size (p < 0.05) of the relationship. Grey dotted line indicates no significant relationship. R2 denotes the proportion of variance explained. Soil nutrients and soil moisture respectively contain several independent variables in the model, to simplify the graph, we group them in the same box in the model. TP: soil total phosphorus content; TC: soil total carbon content; TN: soil total nitrogen content; NH4+-N: soil ammonium nitrogen content; NO3−-N: soil nitrate nitrogen content; SWC: soil moisture content; DWS: soil water storage deficit degree; SWB: soil water balance; ET: evapotranspiration; DM: dry matter accumulation; WUE: water use efficiency. There was a non-significant deviation of the data from the model (χ2/df = 1.14; p = 0.326; Bootstrap P = 0.388; GIF = 0.961; RMSEA = 0.057). Full article ">Figure 5
Annual precipitation and average annual temperature from 2015 to 2021. Full article ">Figure 6
Soil particle distribution. AG: artificial grassland; AL: cropland; NG: natural grassland. Full article ">Figure 7
Map of the experimental site. (a) Artificial grassland and cropland. (b) Natural grassland AG1: Medicago sativa, AG2: Bromus inermis, AL1: Solanum tuberosum, AL2: Avena sativa, NG1: Enclosure, NG2: Cutting. The blank area in (a) is the installation and storage area of experimental equipment. Full article ">

18 pages, 2017 KiB

Open AccessArticle

Quantitative Trait Loci for Genotype and Genotype by Environment Interaction Effects for Seed Yield Plasticity to Terminal Water-Deficit Conditions in Canola (Brassica napus L.)

by Harsh Raman, Nawar Shamaya, Ramethaa Pirathiban, Brett McVittie, Rosy Raman, Brian Cullis and Andrew Easton

Plants 2023, 12(4), 720; https://doi.org/10.3390/plants12040720 - 6 Feb 2023

Cited by 4 | Viewed by 2132

Abstract

Canola plants suffer severe crop yield and oil content reductions when exposed to water-deficit conditions, especially during the reproductive stages of plant development. There is a pressing need to develop canola cultivars that can perform better under increased water-deficit conditions with changing weather [...] Read more.

Canola plants suffer severe crop yield and oil content reductions when exposed to water-deficit conditions, especially during the reproductive stages of plant development. There is a pressing need to develop canola cultivars that can perform better under increased water-deficit conditions with changing weather patterns. In this study, we analysed genetic determinants for the main effects of quantitative trait loci (QTL), (Q), and the interaction effects of QTL and Environment (QE) underlying seed yield and related traits utilising 223 doubled haploid (DH) lines of canola in well-watered and water-deficit conditions under a rainout shelter. Moderate water-deficit at the pre-flowering stage reduced the seed yield to 40.8%. Multi-environmental QTL analysis revealed 23 genomic regions associated with days to flower (DTF), plant height (PH) and seed yield (SY) under well-watered and water-deficit conditions. Three seed yield QTL for main effects were identified on chromosomes A09, C03, and C09, while two were related to QE interactions on A02 and C09. Two QTL regions were co-localised to similar genomic regions for flowering time and seed yield (A09) and the second for plant height and chlorophyll content. The A09 QTL was co-located with a previously mapped QTL for carbon isotope discrimination (Δ¹³C) that showed a positive relationship with seed yield in the same population. Opposite allelic effects for plasticity in seed yield were identified due to QE interactions in response to water stress on chromosomes A02 and C09. Our results showed that QTL’s allelic effects for DTF, PH, and SY and their correlation with Δ¹³C are stable across environments (field conditions, previous study) and contrasting water regimes (this study). The QTL and DH lines that showed high yield under well-watered and water-deficit conditions could be used to manipulate water-use efficiency for breeding improved canola cultivars. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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Figure 1
Frequency distributions of the traits for 223 DH lines from the BC1329/BC9102 breeding population grown in two contrasting water regimes: well-watered (WW) and water-deficit (WD) conditions under a rainout shelter at Wagga Wagga Agricultural Institute. Estimates for the parental lines are shown with arrows. (a) SY: Seed yield; (b) PH: Plant height; (c) SPAD: Chlorophyll content; (d) DTF: Days to flower. Total (additive plus non-additive) common genotype by environment empirical best linear unbiased predictions are used for the traits SY, PH, and SPAD, and total genotype empirical best linear unbiased predictions are used for DTF for the frequency distributions. Full article ">Figure 2
Per cent seed yield decrease of the water-deficit (WD) block compared to the well-watered (WW) block for check cultivars, parental lines and some high and low per cent seed yield decreased DH lines of interest. Full article ">Figure 3
Genetic (total, additive plus non-additive) correlations between traits (a) within well-watered (WW) and (b) within water-deficit (WD) blocks from the multivariate analyses. SY: Seed yield; PH: Plant height; SPAD: Chlorophyll content; DTF: Days to flower. Full article ">Figure 4
Manhattan plots showing genomic regions associated with (a) DTF: Days to flower; (b) SPAD: Chlorophyll content; (c) PH: Plant height; and (d) SY: Seed yield, in the DH population. The QTL for main effects are depicted by ‘*’, and the QTL by Environment interactions are depicted by ‘Δ’. The LOD (-log10p-value) scores presented in the Manhattan plot are from the genome scan for the QTL main effects where the LOD scores of the significant QTL are replaced with the values from the final model. The black dashed line indicates the threshold value for significant SNPs at LOD ≥ 3. The physical positions of DArTseq markers (x-axis) are based on the map position on the Darmor-bzh genome assembly (for detail, see <a href="#app1-plants-12-00720" class="html-app">Supplementary Table S2</a>). Full article ">Figure 5
Graphical representations of QTL associated with multiple traits in a doubled haploid population of B. napus. Map distances (Kosambi) are shown in CentiMorgans (on right). Marker names are shown on the left-hand side. SY: Seed yield, PH: Plant height; SPAD: Chlorophyll content; DTF: Days to flower; Δ13C: carbon isotope discrimination. QTL for main effects are depicted by M, and QTL by Environment interactions are depicted by ‘Q × E’. Field trial 2018: FT 18, Field trial 2019: FT19; pot trial in a rainout shelter 2017: ROS17. Full article ">

13 pages, 853 KiB

Open AccessArticle

Medium-Term Effects of Sprinkler Irrigation Combined with a Single Compost Application on Water and Rice Productivity and Food Safety

by David Peña, Carmen Martín, Damián Fernández-Rodríguez, Jaime Terrón-Sánchez, Luis Andrés Vicente, Ángel Albarrán, Jose Manuel Rato-Nunes and Antonio López-Piñeiro

Plants 2023, 12(3), 456; https://doi.org/10.3390/plants12030456 - 19 Jan 2023

Cited by 4 | Viewed by 2173

Abstract

Traditional rice (Oryza sativa L.) management (tillage and flooding) is unsustainable due to soil degradation and the large amount of irrigation water used, an issue which is exacerbated in the Mediterranean region. Therefore, there is a need to explore rice management strategies [...] Read more.

Traditional rice (Oryza sativa L.) management (tillage and flooding) is unsustainable due to soil degradation and the large amount of irrigation water used, an issue which is exacerbated in the Mediterranean region. Therefore, there is a need to explore rice management strategies in order to improve water-use efficiency and ensure its sustainability. Thus, field experiments were conducted to determine the medium-term effects of different irrigation and tillage methods combined with a single compost application on water and rice productivity, as well as food safety in a semiarid Mediterranean region. The management systems evaluated were: sprinkler irrigation in combination with no-tillage (SNT), sprinkler irrigation in combination with conventional tillage (ST), which were implemented in 2015, and flooding irrigation in combination with conventional tillage (FT), and their homologues (SNT-C, ST-C, and FT-C) with single compost application in 2015. In reference to rice grain yield, the highest values were observed under ST treatment with 10 307 and 11 625 kg ha⁻¹ in 2018 and 2019 respectively; whereas between FT and SNT there were no significant differences, with 8 140 kg ha⁻¹ as mean value through the study. Nevertheless, sprinkler irrigation allowed saving 55% of the total amount of water applied in reference to flooding irrigation. Furthermore, the highest arsenic concentration in grains was found under FT but it decreased with compost application (FT-C) and especially with sprinkler irrigation, regardless of tillage management systems. However, sprinkler irrigation favors the cadmium uptake by plants, although this process was reduced under SNT in reference to ST, and especially under amended compost treatments. Therefore, our results suggested that a combination of sprinkler irrigation and compost application, regardless of the tillage system, could be an excellent strategy for rice management for the Mediterranean environment in terms of water and crop productivity as well as food safety. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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18 pages, 999 KiB

Open AccessEditor’s ChoiceReview

A Review on Regulation of Irrigation Management on Wheat Physiology, Grain Yield, and Quality

by Zhuanyun Si, Anzhen Qin, Yueping Liang, Aiwang Duan and Yang Gao

Plants 2023, 12(4), 692; https://doi.org/10.3390/plants12040692 - 4 Feb 2023

Cited by 17 | Viewed by 5444

Abstract

Irrigation has been pivotal in sustaining wheat as a major food crop in the world and is increasingly important as an adaptation response to climate change. In the context of agricultural production responding to climate change, improved irrigation management plays a significant role [...] Read more.

Irrigation has been pivotal in sustaining wheat as a major food crop in the world and is increasingly important as an adaptation response to climate change. In the context of agricultural production responding to climate change, improved irrigation management plays a significant role in increasing water productivity (WP) and maintaining the sustainable development of water resources. Considering that wheat is a major crop cultivated in arid and semi-arid regions, which consumes high amounts of irrigation water, developing wheat irrigation management with high efficiency is urgently required. Both irrigation scheduling and irrigation methods intricately influence wheat physiology, affect plant growth and development, and regulate grain yield and quality. In this frame, this review aims to provide a critical analysis of the regulation mechanism of irrigation management on wheat physiology, plant growth and yield formation, and grain quality. Considering the key traits involved in wheat water uptake and utilization efficiency, we suggest a series of future perspectives that could enhance the irrigation efficiency of wheat. Full article

(This article belongs to the Special Issue Strategies to Improve Water-Use Efficiency in Plant Production)

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