CN108636356A - A kind of cornstalk biological charcoal and restorative procedure that can repair nitrogen phosphorus pollution of area source - Google Patents

Abstract

The invention belongs to pollution of area source recovery technique fields, and in particular to a kind of cornstalk biological charcoal and restorative procedure that can repair nitrogen phosphorus pollution of area source, the cornstalk biological charcoal are made of the raw material components of following parts by weight：50~200 parts of maize straw charcoal, 0.1~0.5 part of microbial bacterial agent；The restorative procedure includes preparing cornstalk biological charcoal, using cornstalk biological charcoal, long-term cropping.The present invention is using calcium chloride solution to being pre-processed to maize straw, increase its absorption property, the nitrogen and P elements being adsorbed on stalk are focused under the action of microbial bacterial agent and Soil Microorganism and are decomposed, to achieve the purpose that efficiently to repair nitrogen phosphorus pollution of area source.The restorative procedure of the present invention is retained agricultural land soil piecemeal around excrement accumulation area and excrement accumulation area using cornstalk biological charcoal, reduces the migration velocity of nitrogen and P elements in the soil, pollution problem is solved from soil source.

Description

A corn straw biochar capable of remediating nitrogen and phosphorus non-point source pollution and its remediation method

technical field

The invention belongs to the technical field of non-point source pollution restoration, and in particular relates to corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution and a restoration method.

Background technique

Nitrogen and phosphorus are important life elements, irreplaceable components of life support systems, and fundamental elements for sustainable agricultural development. However, it also has two sides. Excessive input of nitrogen and phosphorus fertilizers in the soil, or long-term accumulation of animal manure in farms will not only cause loss and waste of nitrogen and phosphorus elements, but also lead to soil and groundwater pollution, and even cause water quality in rivers and lakes to deteriorate. Nutritization destroys the normal growth conditions of aquatic organisms, causes fish death, and will seriously endanger human health.

When the pollution point is generated, it can migrate to different areas along the water flow path from the point of generation, forming non-point source pollution. For the migration process of non-point source pollution, the main control measures adopted at home and abroad are: (1) source control, that is, to reasonably control the amount of fertilizer application, to avoid excessive fertilization; (2) pollutant interception, that is, to set up ecological ditches and prepare buffer zones (3) Internal source control, once the pollution migrates to rivers, lakes and other water bodies, even if measures such as removing sediment are adopted to reduce the risk of eutrophication in the water body . For example, Chinese patent CN101555071A discloses a method for controlling agricultural non-point source pollution in plain tidal river network areas by using a buffer zone. The patent proposes to select the river bank between the farmland and the river as a buffer zone, and plant different plants according to the runoff direction to form a preparation buffer. belt, using plants to intercept and absorb nutrients in the runoff to achieve a better purification effect. Another example is the Chinese patent CN102839632B, which discloses an ecological slope protection method based on bio-enhanced interception and removal of non-point source pollution. This patent combines traditional ecological restoration of rivers with non-point source pollution control, and uses bio-augmentation technology to achieve refractory degradation in non-point source pollution. removal of organic matter.

However, these existing technologies are all based on the connection between farmland, rivers and lakes. At present, there is still no effective control method for the non-point source pollution of nitrogen and phosphorus caused by animal manure in poultry farms.

Contents of the invention

The purpose of the present invention is to provide a corn stalk biochar and repair method capable of repairing nitrogen and phosphorus non-point source pollution, effectively control the spread of pollution sources from the soil itself, and solve the problem of animal feces nitrogen and phosphorus non-point source pollution sources in poultry farms.

The invention provides corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution, which is made of the following raw material components in parts by weight: 50-200 parts of corn stalk charcoal, 0.1-0.5 parts of microbial agent; The agent is yeast powder, phosphorus-dissolving functional bacteria powder or a mixture of the two;

The corn stalk charcoal is made according to the following method: crush corn stalks into straw fragments, add 5% calcium chloride solution for soaking for 36-48 hours, filter and dry the straw fragments, and then carbonize. Obtain corn stover charcoal;

The phosphate-solubilizing functional bacterium is a bacillus having the function of degrading phosphorus.

Preferably, the above-mentioned corn stalk biochar that can repair nitrogen and phosphorus non-point source pollution, the carbonization is carried out in a tube furnace, and nitrogen gas is introduced for atmosphere protection during carbonization. The heating rate is 25°C/min, and it is maintained for 1 hour after reaching 650°C. , cooled to room temperature.

The present invention also provides a method for repairing nitrogen and phosphorus non-point source pollution by utilizing the above-mentioned corn stalk biochar, comprising the following steps:

S1, weighing each raw material component according to the following parts by weight: 50-200 parts of corn stalk charcoal, 0.1-0.5 part of microbial agent; mixing the weighed components to obtain corn stalk biochar;

S2, application of corn stalk biochar

S21, select an area in the farm as a manure accumulation area, dig ditches in the manure accumulation area and the farmland around the farm, and fill the ditches with corn stalk biochar;

S22, spread corn straw biochar evenly in the manure accumulation area and the farmland around the farm without digging ditches, and plow till the depth of plowing is ≥ 20cm; in S22, the amount of corn straw biochar is changed in the following way: 4 The year is a cycle; the dosage in the first year of each cycle is 20-40kg per mu, and the dosage in the second to fourth years is 1/2 of the dosage in the previous year;

S3, pile up feces in the feces accumulation area, and plant crops in the farmland around the farm to remediate nitrogen and phosphorus non-point source pollution.

Preferably, in the method for repairing nitrogen and phosphorus non-point source pollution by using the above-mentioned corn stalk biochar, the width of the ditch is 5-10 cm, and the depth is 100-200 cm.

Preferably, the ditches extend in a direction perpendicular to the direction of groundwater runoff, and all ditches are arranged at intervals along the direction of groundwater runoff, with an interval of 5-50 m.

Compared with the prior art, the present invention provides a corn straw biochar and repair method capable of repairing nitrogen and phosphorus non-point source pollution, which has the following beneficial effects:

Aiming at the problems of nitrogen and phosphorus pollution caused by poultry and animal feces and farmland pollution around farms, the invention provides corn stalk biochar that can repair nitrogen and phosphorus non-point source pollution, adopts a new corn stalk charcoal preparation method and biochar formula, and utilizes chlorine Calcium solution pretreats corn stalks to increase its adsorption performance. The nitrogen and phosphorus elements adsorbed to the stalks are degraded under the action of microbial agents and microorganisms in the soil, so as to achieve efficient repair of nitrogen and phosphorus surfaces. purpose of source pollution.

Based on the same inventive concept, the present invention also adopts a new restoration method. First, the feces accumulation area is selected, and the feces are concentrated and accumulated to reduce the risk of diffusion; Farmland soil is intercepted in blocks, reducing the migration speed of nitrogen and phosphorus elements in the soil, reducing the diffusion speed of pollution sources, and solving the pollution problem from the source of the soil. Specific experimental studies have proved that the restoration method of the present invention can effectively control the contents of nitrogen and phosphorus in the pond water near the test farmland within a certain range. The adsorption experiment data shows that the removal rate of nitrogen and phosphorus can reach more than 97% within 6 hours, and the effect is remarkable.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments, but it should be understood that the protection scope of the present invention is not limited by specific embodiments. The test methods that do not indicate specific conditions in the following examples are usually operated according to conventional conditions, and the sources of unindicated experimental materials are commercially available. Since they do not involve the invention point, the steps are not described in detail.

In the following examples 1 to 3 and experiments, the yeast powder is all yeast powder of Jining Jinyijun Biotechnology Co., Ltd.; Shandong Lvlong Biotechnology Co., Ltd.

The invention provides corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution, which is made of the following raw material components in parts by weight: 50-200 parts of corn stalk charcoal, 0.1-0.5 parts of microbial agent; The agent is yeast powder, phosphorus-dissolving functional bacteria powder or a mixture of the two;

The corn stalk charcoal is made according to the following method: crush corn stalks into straw fragments, add 5% calcium chloride solution for soaking for 36-48 hours, filter and dry the straw fragments, and then carbonize. Obtain corn stover charcoal;

The phosphate-solubilizing functional bacterium is a bacillus having the function of degrading phosphorus.

Based on the same inventive concept, the present invention also provides a method for using the corn stalk biochar to repair nitrogen and phosphorus non-point source pollution, comprising the following steps:

S1, weighing each raw material component according to the following parts by weight: 50-200 parts of corn stalk charcoal, 0.1-0.5 part of microbial agent; mixing the weighed components to obtain corn stalk biochar;

S2, application of corn stalk biochar

S21, select an area in the farm as a manure accumulation area, dig ditches in the manure accumulation area and the farmland around the farm, and fill the ditches with corn stalk biochar;

S22, spread corn straw biochar evenly in the manure accumulation area and the farmland around the farm without digging ditches, and plow till the depth of plowing is ≥ 20cm; in S22, the amount of corn straw biochar is changed in the following way: 4 The year is a cycle; the dosage in the first year of each cycle is 20-40kg per mu, and the dosage in the second to fourth years is 1/2 of the dosage in the previous year;

S3, pile up feces in the feces accumulation area, and plant crops in the farmland around the farm to remediate nitrogen and phosphorus non-point source pollution.

Specifically include the following examples. In the following examples, the selected locations for testing polluted farmland are poultry farms and their surrounding farmlands.

Example 1

A corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution is made of the following raw material components in parts by weight: 50 parts of corn stalk charcoal, 0.1 part of microbial agent; the microbial agent is yeast powder; the Corn stalk charcoal is made according to the following method: crush corn stalks into 1-2 cm straw fragments, add 5% mass fraction of calcium chloride solution to soak for 36 hours, filter and dry at 105°C (moisture content ≤ 10% ) straw fragments, and then carbonized to obtain corn straw charcoal. The carbonization is carried out in a tube furnace, and nitrogen gas is introduced to protect the atmosphere during carbonization. The heating rate is 25°C/min. After reaching 650°C, it is maintained for 1 hour and cooled to room temperature.

The method for remediating nitrogen and phosphorus non-point source pollution by using corn stalk biochar described in Example 1 may further comprise the steps:

S1, weighing each raw material component according to the following parts by weight: 50 parts of corn stalk charcoal, 0.1 part of microbial inoculant; mixing the weighed components to obtain corn stalk biochar;

S2, application of corn stalk biochar

S21, select an area of 40 square meters in the farm as the excrement accumulation area, dig ditches in the excrement accumulation area and the farmland around the farm, the width of the ditches is 5 cm, the depth is 100 cm, and corn stalk biochar is filled in the ditches , filled to be flush with the farmland soil;

In S22, corn stalk biochar was evenly sprinkled in the manure accumulation area and the farmland around the farm without ditches, and plowed to a depth of 20cm; in S22, the amount of corn stalk biochar was changed in the following way: 4 years It is a cycle; in each cycle, the dosage in the first year is 20kg per mu, the annual dosage in the second year is 10kg per mu, the annual dosage in the third year is 5kg per mu, and the annual dosage in the fourth year is 2.5kg per mu;

S3, pile up feces in the feces accumulation area, and plant crop wheat in the farmland around the farm to build an ecological restoration field for the restoration of nitrogen and phosphorus non-point source pollution.

After the method of Example 1 was sprinkled with corn stalk biochar for one year, the N content in the 100cm depth layer soil decreased from 350.01 mg/kg to 125.56 mg/kg, and the P content decreased from 223.50 mg/kg to 103.74 mg/kg. The content of N and P in the farmland 100 meters away from the farm did not increase.

Example 2

A kind of corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution, made of the following raw material components in parts by weight: 200 parts of corn stalk charcoal, 0.5 part of microbial agent; the microbial agent is a huge Bacillus powder; the corn stalk charcoal is made according to the following method: crush the corn stalks into 1-2 cm straw fragments, add 5% mass fraction of calcium chloride solution to soak for 36 hours, filter and dry at 105°C (moisture content≤10%) straw fragments, and then carbonize to obtain corn straw charcoal. The carbonization is carried out in a tube furnace, and nitrogen gas is introduced to protect the atmosphere during carbonization. The heating rate is 25°C/min. After reaching 650°C, it is maintained for 1 hour and cooled to room temperature.

The method for remediating nitrogen and phosphorus non-point source pollution by using corn stalk biochar described in Example 2 comprises the following steps:

S1, weighing each raw material component according to the following parts by weight: 200 parts of corn stalk charcoal, 0.5 part of microbial inoculant; mixing the weighed components to obtain corn stalk biochar;

S2, application of corn stalk biochar

S21, select an area of 30 square meters in the farm as the excrement accumulation area, dig ditches in the excrement accumulation area and the farmland around the farm, the width of the ditches is 10 cm, the depth is 200 cm, and corn stalk biochar is filled in the ditches , filled to be flush with the farmland soil;

In S22, corn stalk biochar was evenly sprinkled in the manure accumulation area and the farmland around the farm without ditches, and plowed to a depth of 25 cm; in S22, the amount of corn stalk biochar was changed in the following way: 4 years It is a cycle; in each cycle, the dosage is 40kg per mu in the first year, 20kg per mu in the second year, 10kg per mu in the third year, and 5kg per mu in the fourth year;

S3, pile up feces in the feces accumulation area, and plant crop wheat in the farmland around the farm to build an ecological restoration field for the restoration of nitrogen and phosphorus non-point source pollution.

After the method of Example 2 was sprinkled with corn stalk biochar for one year, the N content in the 100cm deep layer soil decreased from 425.69 mg/kg to 220.12 mg/kg, and the P content decreased from 255.30 mg/kg to 140.75 mg/kg. The content of N and P in the farmland 100 meters away from the farm did not increase.

Example 3

A corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution is made of the following raw material components in parts by weight: 100 parts of corn stalk charcoal, 0.2 parts of microbial agent; the microbial agent is yeast powder and has a solution The mixture of Bacillus megaterium powder with phosphorus function in a mass ratio of 1:1; the corn stalk charcoal is made according to the following method: crush corn stalks into 1-2 cm straw fragments, add 5% mass fraction Soak in the calcium chloride solution for 48 hours, filter and dry at 105° C. (moisture content ≤ 10%) straw fragments, and then carbonize to obtain corn straw charcoal. The carbonization is carried out in a tube furnace, and nitrogen gas is introduced to protect the atmosphere during carbonization. The heating rate is 25°C/min. After reaching 650°C, it is maintained for 1 hour and cooled to room temperature.

The method for remediating nitrogen and phosphorus non-point source pollution by using corn stalk biochar described in Example 2 comprises the following steps:

S1, weighing each raw material component according to the following parts by weight: 100 parts of corn stalk charcoal, 0.2 part of microbial inoculant; mixing the weighed components to make corn stalk biochar;

S2, application of corn stalk biochar

S21, select an area of 20 square meters in the farm as the excrement accumulation area, dig ditches in the excrement accumulation area and the farmland around the farm, the width of the ditches is 10 cm, the depth is 150 cm, and corn stalk biochar is filled in the ditches , filled to be flush with the farmland soil;

In S22, corn stalk biochar was evenly sprinkled in the manure accumulation area and the farmland around the farm without ditches, and plowed to a depth of 25 cm; in S22, the amount of corn stalk biochar was changed in the following way: 4 years It is a cycle; in each cycle, the dosage in the first year is 30kg per mu, the annual dosage in the second year is 15kg per mu, the annual dosage in the third year is 7.5kg per mu, and the annual dosage in the fourth year is 3.75kg per mu;

S3, pile up feces in the feces accumulation area, and plant crop wheat in the farmland around the farm to build an ecological restoration field for the restoration of nitrogen and phosphorus non-point source pollution.

After the method of Example 3 was sprinkled with corn stalk biochar for one year, the N content in the 100cm deep layer soil decreased from 389.32 mg/kg to 120.78 mg/kg, and the P content decreased from 251.40 mg/kg to 110.65 mg/kg. The content of N and P in the farmland 100 meters away from the farm did not increase.

Comparative example 1

When corn stalk biochar is used, step S21 is omitted, and the rest of the operations are the same as in Example 1.

After the method of Example 1 was sprinkled with corn stalk biochar for one year, the N content in the soil at a depth of 100 cm decreased from 354.86 mg/kg to 218.35 mg/kg, and the P content decreased from 224.50 mg/kg to 146.21 mg/kg. The content of N and P in the farmland 100 meters away from the farm increased by 2.1% and 2.3%, respectively.

In order to prove the effect of the corn stalk biochar of the present invention on removing nitrogen and phosphorus, we conducted the following experiments.

1. Settings of different experimental groups:

Experimental group 1: a corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution, made of the following raw material components in parts by weight: 50 parts of corn stalk charcoal, 0.1 part of microbial agent; the microbial agent is yeast Powder: weighing each component according to the weight ratio, and mixing to prepare corn stalk biochar. The preparation method of corn stalk charcoal is the same as in Example 1.

Experimental group 2: a corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution, made of the following raw material components in parts by weight: 50 parts of corn stalk charcoal, 0.1 part of microbial agent; Bacillus megaterium powder with phosphorus function; each component is weighed in proportion by weight and mixed to make corn stalk biochar. The preparation method of corn stalk charcoal is the same as in Example 1.

Experimental group 3: a corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution, made of the following raw material components in parts by weight: 50 parts of corn stalk charcoal, 0.1 part of microbial agent; the microbial agent is yeast powder and Bacillus megaterium powder with phosphorus-solubilizing function in a mass ratio of 1:1; each component is weighed in proportion by weight and mixed to make corn stalk biochar. The preparation method of corn stalk charcoal is the same as in Example 1.

Experimental group 4: The preparation method of corn stalk charcoal is as follows: crush corn stalks into straw fragments, dry the straw fragments at 105°C, and then carbonize to obtain corn straw charcoal; the carbonization uses a tube furnace for carbonization. Introduce nitrogen for atmosphere protection, heating rate is 25°C/min, maintain 1h after reaching 650°C, and cool to room temperature; no microbial agent is used; other operations are the same as experimental group 1.

Experimental group 5: Change the soaking time of calcium chloride solution to 60h, and the rest of the operations are the same as experimental group 1.

Experimental group 6: No microbial agent was used, and other operations were the same as experimental group 1.

2. Adsorption experiment

(1) Phosphorus adsorption experiment operation: This experiment was carried out at room temperature, 4g of biochar was added to 12mg/L potassium dihydrogen phosphate solution, adsorbed for 48h, and the residual P content in the solution was measured at 30min, 6h, and 12h respectively , Calculation of P removal rate = (original P content - residual P content) × 100% / original P content.

(2) Nitrogen adsorption experiment operation: this experiment was carried out at room temperature, 4g of biochar was added to 12mg/L ammonium chloride solution, adsorbed for 48h, and the residual N content in the solution was measured at 30min, 6h, and 12h respectively. Calculate N removal rate=(original N content-residual N content)×100%/original N content.

(3) Composite ion adsorption experiment operation: This experiment was carried out at room temperature, 4g of biochar was added to 1L of composite ion solution, and 6mg of ammonium chloride and 6mg of potassium dihydrogen phosphate were added to 1L of composite ion solution; After adsorption for 48 hours, measure the amount of N and P remaining in the solution at 30 minutes, 6 hours and 12 hours respectively, and calculate the removal rates of N and P respectively.

Each of the above-mentioned experimental groups did three parallels, and the average value was taken. The experimental results are shown in Table 1. From the data in Table 1, it can be seen that no matter whether it is a single phosphorus or nitrogen adsorption experiment or a composite ion adsorption experiment, the experimental groups 1 to 3 were in 12h. The P removal rate and N removal rate are good, indicating that the corn biochar in Examples 1-3 has good adsorption nitrogen and phosphorus effects, and the removal rate can reach more than 95% after 12 hours, which can be used to repair nitrogen and phosphorus non-point source pollution. . Experimental group 4 used straw without calcium chloride treatment, so the adsorption effect was poor, and the removal rate was less than 5%. Experimental group 5 prolonged the immersion time of calcium chloride solution, but the removal effect was worse than that of experimental groups 1-3, indicating that the longer the immersion time, the better. The removal effect of experimental group 6 was also worse than that of experimental groups 1-3, and the microbial agent had certain effects on the degradation of nitrogen and phosphorus.

The adsorption capacity test found that the corn stalk charcoal prepared in Examples 1-3 (i.e. experimental groups 1-3) had a maximum adsorption capacity of 48.1 mg/g for PO ^3- ; a maximum adsorption capacity for NH ⁴⁺ of up to 45.2 mg/g.

Table 1 N, P removal rate data of different experimental groups

It should be noted that, in order to improve the efficiency of remediating pollution, the ditches extend in a direction perpendicular to the direction of groundwater runoff, and all ditches are arranged at intervals along the direction of groundwater runoff, with an interval of 5-50 m. Because the corn straw biochar is perpendicular to the runoff direction of groundwater at this time, it can effectively block the lateral migration of nitrogen and phosphorus within a certain depth. When the ditch is filled with corn stalk biochar and reaches the adsorption equilibrium, it is dug out and refilled with new corn stalk biochar; and the dug out corn stalk biochar is used as organic fertilizer in areas where the soil is deficient in nitrogen and phosphorus, as a slow-release fertilizer Application; the excavated corn stalk biochar can also be fully washed with water, dried to reactivate the straw biochar, and then reused to repair nitrogen and phosphorus non-point source pollution.

It should be noted that the phosphorus-solubilizing functional bacteria described in the present invention are Bacillus with the function of degrading phosphorus; the yeast and the phosphorus-solubilizing functional bacteria can be non-pathogenic strains, such as Saccharomyces cerevisiae strains, or The Bacillus amyloliquefaciens with phosphorus-solubilizing function has the same method of use, so only the above examples are used as an example for illustration.

It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods adopted are the same as those in the embodiments, in order to avoid repeating , the invention describes preferred embodiments. While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (5)

1. A corn stalk biochar that can repair nitrogen and phosphorus non-point source pollution is characterized in that it is made of the following raw material components in parts by weight: 50 to 200 parts of corn stalk charcoal, 0.1 to 0.5 parts of microbial bacterial agent; The microbial agent is yeast powder, phosphorus-dissolving functional bacteria powder or a mixture of the two; The corn stalk charcoal is made according to the following method: crush corn stalks into straw fragments, add 5% calcium chloride solution for soaking for 36-48 hours, filter and dry the straw fragments, and then carbonize. Obtain corn stover charcoal; The phosphate-solubilizing functional bacterium is a bacillus having the function of degrading phosphorus. 2. The corn stalk biochar capable of repairing nitrogen and phosphorus non-point source pollution according to claim 1, characterized in that, the carbonization adopts a tube furnace for carbonization, nitrogen gas is introduced for atmosphere protection during carbonization, and the heating rate is 25° C. /min, maintain 1h after reaching 650°C, and cool to room temperature. 3. A method utilizing corn stalk biochar to remediate nitrogen and phosphorus non-point source pollution according to claim 1, comprising the following steps: S1, weighing each raw material component according to the following parts by weight: 50-200 parts of corn stalk charcoal, 0.1-0.5 part of microbial agent; mixing the weighed components to obtain corn stalk biochar; S2, application of corn stalk biochar S21, select an area in the farm as a manure accumulation area, dig ditches in the manure accumulation area and the farmland around the farm, and fill the ditches with corn stalk biochar; S22, spread corn straw biochar evenly in the manure accumulation area and the farmland area around the farm without digging ditches, and plow, with a plowing depth ≥ 20cm; in S22, the amount of corn straw biochar is changed in the following way: 4 The year is a cycle; the dosage in the first year of each cycle is 20-40kg per mu, and the dosage in the second to fourth years is 1/2 of the dosage in the previous year; S3, pile up feces in the feces accumulation area, and plant crops in the farmland around the farm to remediate nitrogen and phosphorus non-point source pollution. 4. The method for repairing nitrogen and phosphorus non-point source pollution according to claim 3, characterized in that, the width of the ditch is 5-10 cm, and the depth is 100-200 cm. 5. The method for repairing nitrogen and phosphorus non-point source pollution according to claim 3, wherein the ditches extend in a direction perpendicular to the direction of groundwater runoff, and all ditches are arranged at intervals along the direction of groundwater runoff, with an interval of 5 ~50m.