Background technology
Along with socioeconomic development, the Heavy Metal Pollution In Cultivated Land area constantly enlarges, and pollution level also constantly increases the weight of.Heavy Metal Pollution In Cultivated Land is mainly from Industrial " three Waste " discharge, the pollution of sanitary sewage and rubbish and the unreasonable use that contains heavy metal agricultural chemicals, chemical fertilizer.According to latest survey, show, China is subject to the cultivated area of heavy metal pollution to reach 2,000 ten thousand hectares, accounts for 1/6 of national total cultivated area.For this reason, improvement arable land heavy metal pollution is extremely urgent.The pollution of cadmium (Cd) in environment of one of heavy metal " five poisonous creatures: scorpion, viper, centipede, house lizard, toad " has the characteristics such as disguise, chronicity and irreversibility, and in soil, the holdup time is grown, can not be degraded, and through approach such as food chains, finally affects human health, affects very large." cadmium rice " event is caused by cadmium pollution because of soil.Therefore, cadmium pollution soil is badly in need of being governed.
At present, the heavy metal phytoremediation technology generally be considered to have the incomparable expense of physics, chemical repair method cheap, not the damage field ground structure, do not cause the characteristics such as secondary pollution, become an emerging technology in repairing heavy metal in soil Pollution Study field, and carried out in the world the screening of super enriching plant.The super enriching plant of having found has: the kinds more than 450 such as Indian mustard, penny cress, ciliate desert-grass.Because known super enriching plant the upperground part biomass is generally less than normal, growth is slow, and much derives from heavy metal mine (belonging to the Mine ecology type), poor to the orchard soil adaptive capacity to environment, growth scope is narrow, has limited applying of phytoremediation technology.For this reason, find adapting to orchard soil environment, fast growth, cadmium enriching plant new species or new varieties that fertility is strong, is cadmium pollution orchard soil phytoremediation technology urgent problem.
Floristics or the variety source of just current cadmium pollution soil reparation, the plant variety resource that can be used for the cadmium pollution soil reparation can not meet the actual needs of zones of different, soil type, further the screening available resources.In addition, plant has the abundantest species resource, determine which plant is Cd-hyperaccumulator, needs a large amount of human and material resources of cost and financial resources, and this has also just restricted efficiency and the application of phytoremediation.
In orchard, weeds are compared the characteristics that generally have stronger degeneration-resistant border ability and contention environmental resource ability with fruit tree, are the plant groups of the height evolution that produces under artificial and natural selection.Orchard weed has that biomass is large, the characteristics rapidly of growing.Therefore, filter out the heavy metal cadmium super enriching plant from orchard weed, the biomass that not only can make up existing super enriching plant is less, poor growth, the narrow shortcoming of growth scope, and can gather materials on the spot, use on the spot, avoided introducing a fine variety the potential problems that exist in process.
Root of bidentate achyranthes chrysanthemum (Latin is called Galinsoga parviflora Cav.) is composite family ox achyranthes chrysanthemum spp annual herb plant, orchard weed, and plant height 10-80cm, anti-the moon, base portion has stronger branch ability, after harvesting, can again sprout new buds.Through inventor's Primary Study in early stage, find, root of bidentate achyranthes chrysanthemum has significantly super enriched character to the heavy metal cadmium in soil environment.Therefore, problem that and how to utilize root of bidentate achyranthes chrysanthemum solution orchard soil cadmium metal to exceed standard is the problem that we face and will solve at present.
Summary of the invention
The purpose of the embodiment of the present invention is to provide a kind of method of the reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum, is intended to solve the problem of the biological prosthetic plant species inadequate resource of heavy metal pollution of soil.
The embodiment of the present invention is achieved in that a kind of method of the reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum, and the method for being somebody's turn to do the reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum comprises the following steps:
Adopt direct transplanting method, also can adopt the seed sowing mode to carry out root of bidentate achyranthes chrysanthemum seedling and prepare, planting density 10 * 10cm;
Water and guarantee that field soil moisture water-holding capacity is about 80%, carry out the daily management (even seedling, weed a garden etc.) of root of bidentate achyranthes chrysanthemum;
Harvesting is processed: after 60 days, the aerial part of root of bidentate achyranthes chrysanthemum is gathered in.
Further, adopt the method for direct transplanting method preparation seedling as follows:
Under natural conditions, the composite family ox achyranthes chrysanthemum spp plant root of bidentate achyranthes chrysanthemum seedling collected is directly transplanted in the middle of the soil that cadmium heavy metal pollution is arranged.
Further, to prepare the method for seedling as follows for the seed sowing mode:
Seed sowing mode under field conditions (factors), directly be seeded in the composite family ox achyranthes chrysanthemum spp plant root of bidentate achyranthes chrysanthemum seed collected in the middle of the soil of heavy metal cadmium.
Further, the requirement of the daily management of root of bidentate achyranthes chrysanthemum is to remain on 80% of field capacity.
Further, seedling grows rear even seedling, and density is controlled at 10 * 10cm.
Further, the time of root of bidentate achyranthes chrysanthemum harvesting is: root of bidentate achyranthes chrysanthemum seedling prepares to finish latter 60 days.
Root of bidentate achyranthes chrysanthemum in the method for the reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum provided by the invention is composite family ox achyranthes chrysanthemum spp annual herb plant, and the cadmium heavy metal is had to patience and super enriched character.The present invention takes full advantage of the super enriched character of root of bidentate achyranthes chrysanthemum to heavy metal cadmium, by its seedling replanting or by its seed sowing to by the soil of heavy metal cadmium, cadmium heavy metal in the absorption and accumulation contaminated soil, and its major part is transported to aerial part, reduce the content of Cadmium in Soil, when aerial part forms certain biomass, harvesting, thus reach the purpose that reduces Cadium In Polluted Soil content.
In addition, because root of bidentate achyranthes chrysanthemum fertility is strong, growth is quick, anti-the moon, and base portion has stronger branch ability, after harvesting, can again sprout new buds, almost can plant throughout the year in southern area of China, can grow on extremely barren soil, extensive management in its growth course, thereby cost is lower, workable, for the phytoremediation of heavy metal cadmium orchard soil has been developed new plant germplasm resource.
The specific embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.
Fig. 1 shows the flow process of the method for the reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum provided by the invention.For convenience of explanation, only show part related to the present invention.
The method of a kind of reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum that embodiments of the invention provide comprises the following steps:
Adopt direct transplanting method, also can adopt the seed sowing mode to carry out root of bidentate achyranthes chrysanthemum seedling and prepare;
Irregularly water and guarantee 80% left and right of soil moisture conservation at field capacity according to the soil moisture actual conditions, carry out the daily management (even seedling, weed a garden etc.) of root of bidentate achyranthes chrysanthemum;
Harvesting is processed: after 60 days, the aerial part of root of bidentate achyranthes chrysanthemum is gathered in.
As a prioritization scheme of the embodiment of the present invention, adopt the method for direct transplanting method preparation seedling as follows:
Under natural conditions, the composite family ox achyranthes chrysanthemum spp plant root of bidentate achyranthes chrysanthemum seedling collected is directly transplanted in the middle of the soil that cadmium heavy metal pollution is arranged to planting density 10 * 10cm.
As a prioritization scheme of the embodiment of the present invention, the method that the seed sowing mode is prepared seedling is as follows:
Seed sowing mode under field conditions (factors), directly be seeded in the composite family ox achyranthes chrysanthemum spp plant root of bidentate achyranthes chrysanthemum seed collected in the middle of the soil of heavy metal cadmium, and seedling grows rear even seedling, and density is controlled at 10 * 10cm.
As a prioritization scheme of the embodiment of the present invention, the requirement of the daily management of root of bidentate achyranthes chrysanthemum is to remain on 80% of field capacity.
As a prioritization scheme of the embodiment of the present invention, the time of root of bidentate achyranthes chrysanthemum harvesting is: root of bidentate achyranthes chrysanthemum seedling prepares to finish latter 60 days.
Below in conjunction with drawings and the specific embodiments, application principle of the present invention is further described.
The method of the reparation orchard soil heavy metal cadmium based on root of bidentate achyranthes chrysanthemum that the embodiment of the present invention provides comprises the following steps:
S101: adopt direct transplanting method, also can adopt the seed sowing mode to carry out root of bidentate achyranthes chrysanthemum seedling and prepare;
S102: water and guarantee that field soil moisture water-holding capacity is 80%, carries out the daily management of root of bidentate achyranthes chrysanthemum;
S103: harvesting is processed: the aerial part to root of bidentate achyranthes chrysanthemum is gathered in.
Specific embodiment provided by the invention is as follows:
Test example 1: potted plant concentration gradient test (little basin)
The enforcement place of the embodiment of the present invention: be located at farm, school district, Sichuan Agricultural University Yaan.
The embodiment of the present invention adopts the method for potted plant simulated soil heavy metal pollution, in spring (at the beginning of 2 months), the composite family ox achyranthes chrysanthemum spp plant root of bidentate achyranthes chrysanthemum of transplanting (Latin is called Galinsoga parviflora Cav.) seedling (two true leaves launch) is directly picked up from farm, school district, Sichuan Agricultural University Yaan.By root of bidentate achyranthes chrysanthemum seedling cultivation in the potted plant soil of the heavy metal cadmium that applies the variable concentrations gradient (soil is taken from orchard), basin specification 15 * 18cm (height * diameter), every basin fills native 3kg, every basin is planted 5 strains, repeats for 3 times.Cultivate in transparent rain shade, according to the soil moisture actual conditions, irregularly water and guarantee 80% left and right of soil moisture conservation at field capacity, after 60 days, plant to be planted is after full-bloom stage, and the harvesting plant, measure the heavy metal cadmium content in plant.
Inventive embodiments is established 5 processing altogether, be respectively CK and (do not apply heavy metal cadmium, 0mg/kg) He 4 have applied the test of variable concentrations heavy metal cadmium, and applying concentration is 25mg/kg, 50mg/kg, 75mg/kg, 100mg/kg, and the Heavy Metals applied is respectively CdCl
22.5H
2o, be AR, with the form of solution, joins in soil, fully mixes plantation root of bidentate achyranthes chrysanthemum seedling after the balance surrounding.
Embodiment of the present invention result is as follows:
Root of bidentate achyranthes chrysanthemum biomass estimation the results are shown in following table 1:
The different cadmium concentrations of table 1 are processed the biomass feature of lower root of bidentate achyranthes chrysanthemum
Table 1 result shows, along with Cadmium in Soil applies the increase of concentration, the biomass of individual tree of root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part reduces gradually.Compared with the control, when Cadmium in Soil applies concentration and is less than or equal to 25mg/kg, root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part biomass of individual tree difference are not remarkable, have shown having the patience that cadmium is stronger.Meanwhile, at higher Cadmium in Soil, apply under concentration, root of bidentate achyranthes chrysanthemum aerial part biomass of individual tree reduces obviously, and significant difference, but root of bidentate achyranthes chrysanthemum also can normal growth, has illustrated that root of bidentate achyranthes chrysanthemum has very strong patience.From root cap recently, along with Cadmium in Soil applies the increase of concentration, when Cadmium in Soil applies concentration and is less than 75mg/kg, root/shoot ratio is the trend of increase, illustrated that root of bidentate achyranthes chrysanthemum progressively increases the shared proportion of root biomass to strengthen the patience to cadmium, is conducive to for the rehabilitating soil cadmium pollution.
In root of bidentate achyranthes chrysanthemum body, the cadmium content measurement result is shown in following table 2:
The different cadmium concentrations of table 2 are processed the super enrichment characteristics of lower root of bidentate achyranthes chrysanthemum to cadmium
TF is transfer ratio: aerial part cadmium content/root system cadmium content, BCF is concentration coefficient: aerial part cadmium content/Cadmium in Soil concentration for the treatment of.
Table 2 result shows, when Cadmium in Soil applies concentration and is greater than 0mg/kg, root of bidentate achyranthes chrysanthemum overground part transfer ratio all is greater than 1, and transfer ratio also is greater than 1.Apply the increase of concentration with Cadmium in Soil, the cadmium content of root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part also increases.When Cadmium in Soil applies concentration and is 75mg/kg, root of bidentate achyranthes chrysanthemum aerial part cadmium content meets and exceeds 100mg/kg, reaches the standard of super enriching plant.
Patience and the enrichment characteristics of comprehensive root of bidentate achyranthes chrysanthemum to cadmium, the definition according to Brooks to super enriching plant, tentatively can determine that root of bidentate achyranthes chrysanthemum is Cd-hyperaccumulator, has stronger repair ability to the cadmium pollution orchard soil.
Root of bidentate achyranthes chrysanthemum sees following table 3 to the accumulation measurement result of cadmium:
The different cadmium concentrations of table 3 are processed the accumulation of lower root of bidentate achyranthes chrysanthemum to cadmium
Table 3 result shows, applies the increase of concentration with Cadmium in Soil, and root of bidentate achyranthes chrysanthemum is the trend of falling after rising to the accumulation of cadmium.When Cadmium in Soil applies concentration and is 50mg/kg, root of bidentate achyranthes chrysanthemum cadmium root system, stem, blade and aerial part cadmium accumulation all reach maximum, its root system, stem, blade and aerial part cadmium accumulation are respectively 15.58 μ g/ strains, 29.30 μ g/ strains, 42.49 μ g/ strains and 71.79 μ g/ strains, and repairing effect is better.When Cadmium in Soil applies concentration and is 25mg/kg and 75mg/kg, root of bidentate achyranthes chrysanthemum aerial part cadmium accumulation is only second to Cadmium in Soil, and to apply concentration be 50mg/kg, and gap is little.
Test example 2: large basin test (being equivalent to plot experiment)
The enforcement place of the embodiment of the present invention: be located at farm, school district, Sichuan Agricultural University Yaan.
The embodiment of the present invention adopts the method (soil volume and weight and community are suitable) of potted plant simulated soil heavy metal pollution, in spring (at the beginning of 4 months), the composite family ox achyranthes chrysanthemum spp plant root of bidentate achyranthes chrysanthemum of transplanting (Latin is called Galinsoga parviflora Cav.) seedling (two true leaves launch) is directly picked up from farm, school district, Sichuan Agricultural University Yaan.By root of bidentate achyranthes chrysanthemum seedling cultivation in the potted plant soil of the heavy metal cadmium that applies the variable concentrations gradient (soil is taken from orchard), basin specification 20 * 27cm (height * diameter), every basin fills native 12kg, every basin is planted 5 strains, the about 10cm of distance between rows and hills repeats for 3 times.Cultivate in transparent rain shade, according to the soil moisture actual conditions, irregularly water and guarantee 80% left and right of soil moisture conservation at field capacity, after 60 days, plant to be planted is after full-bloom stage, and the harvesting plant, measure the heavy metal cadmium content in plant.
Inventive embodiments is established 5 processing altogether, be respectively CK and (do not apply heavy metal cadmium, 0mg/kg) He 4 have applied the test of variable concentrations heavy metal cadmium, and applying concentration is 25mg/kg, 50mg/kg, 75mg/kg, 100mg/kg, and the Heavy Metals applied is respectively CdCl
22.5H
2o, be AR, with the form of solution, joins in soil, fully mixes plantation root of bidentate achyranthes chrysanthemum seedling after the balance surrounding.
Embodiment of the present invention result is as follows:
Plot experiment root of bidentate achyranthes chrysanthemum biomass estimation the results are shown in following table 4:
The biomass feature of table 4 plot experiment root of bidentate achyranthes chrysanthemum
Table 4 result shows, along with Cadmium in Soil applies the increase of concentration, root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part biomass of individual tree reduce gradually.Compared with the control, when Cadmium in Soil applies concentration and is less than or equal to 25mg/kg, root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part biomass of individual tree difference are not remarkable, have shown the patience stronger to cadmium.This result with test example 1 is consistent, but the corresponding soils cadmium applies the root of bidentate achyranthes chrysanthemum biomass of concentration, increases approximately one times.Meanwhile, at higher Cadmium in Soil, apply under concentration, root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part biomass of individual tree reduce obviously, but root of bidentate achyranthes chrysanthemum also can normal growth, has also illustrated that root of bidentate achyranthes chrysanthemum has very strong patience.From root cap recently, along with Cadmium in Soil applies the increase of concentration, when Cadmium in Soil applies concentration and is less than 75mg/kg, root/shoot ratio is the trend of increase, also embodied root of bidentate achyranthes chrysanthemum and there is very strong patience, but root cap ratio is less than test example 1, illustrate and increase the growth that soil body volume is conducive to promote root of bidentate achyranthes chrysanthemum.
In plot experiment root of bidentate achyranthes chrysanthemum body, the cadmium content measurement result is shown in following table 5:
The super enrichment characteristics of table 5 plot experiment root of bidentate achyranthes chrysanthemum to cadmium
TF is transfer ratio: aerial part cadmium content/root system cadmium content, BCF is concentration coefficient: aerial part cadmium content/Cadmium in Soil concentration for the treatment of.
Table 1 result shows, when Cadmium in Soil applies concentration and is greater than 0mg/kg, root of bidentate achyranthes chrysanthemum overground part transfer ratio all is greater than 1, and transfer ratio also is greater than 1.Apply the increase of concentration with Cadmium in Soil, root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part cadmium content also increase.When Cadmium in Soil applies concentration and is 75mg/kg, root of bidentate achyranthes chrysanthemum aerial part cadmium content reaches 100mg/kg, reach the standard of super enriching plant, but cadmium content is less than the test example 1 that the corresponding soils cadmium applies concentration, although the growth that has promoted root of bidentate achyranthes chrysanthemum is described after soil body volume increases, increased biomass, but in body, cadmium content decreases.
Patience and the enrichment characteristics of comprehensive root of bidentate achyranthes chrysanthemum to cadmium, the definition according to Brooks to super enriching plant, further determine that root of bidentate achyranthes chrysanthemum is Cd-hyperaccumulator, has stronger repair ability to cadmium pollution soil.
Plot experiment root of bidentate achyranthes chrysanthemum the results are shown in following table 6 to the accumulation of cadmium:
The accumulation of table 6 plot experiment root of bidentate achyranthes chrysanthemum to cadmium
Table 6 result shows, different from test example 1, applies the increase of concentration with Cadmium in Soil, and root of bidentate achyranthes chrysanthemum is the trend of increase to the accumulation of cadmium.When Cadmium in Soil applies concentration and is 100mg/kg, root of bidentate achyranthes chrysanthemum root system, stem, blade and aerial part cadmium accumulation all reach maximum, its root system, stem, blade and aerial part cadmium accumulation are respectively 31.50 μ g/ strains, 105.12 μ g/ strains, 100.50 μ g/ strains and 205.62 μ g/ strains, repairing effect is better than test example 1 far away, and this is conducive to root of bidentate achyranthes chrysanthemum for the production of the cadmium pollution of upper reparation orchard soil.Therefore, in Cadmium in Soil concentration, be less than or equal in the orchard soil of 100mg/kg, root of bidentate achyranthes chrysanthemum all has good repairing effect.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.