Method for improving saline and alkaline farmland

Abstract

The application provides a saline-alkali farmland improvement method, and belongs to the technical field of saline-alkali soil remediation, which comprises the following steps: irrigating and soaking the saline-alkali farmland to be improved, stirring and plowing the saline-alkali farmland, and irrigating or drip irrigating the saline-alkali farmland by cooperating with the application of microbial inoculants; adjusting the salinity of the saline-alkali farmland by using active calcium fertilizer; plowing the saline-alkali farmland after the salinity adjustment, and planting crops; field management according to the growth habits of the crops; harvesting the crops, and post-treating the saline-alkali farmland after the harvesting; the field management comprises applying stress-resistant foliar fertilizer and amino acid mother liquor to the crops in the middle and late growth periods of the crops. The method can effectively block salt, supplement water and fertilizer, has a good improvement effect on the saline-alkali farmland, reduces the salt-alkali stress on the crops, and is matched with a high-value crop planting scheme, so that the yield and stress resistance of the crops on the saline-alkali farmland are improved, and the utilization rate and economic benefits of the saline-alkali farmland are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of saline-alkali soil remediation, and particularly relates to a method for improving saline-alkali farmland. BACKGROUND

[0002] The saline-alkali land is a kind of salt accumulation, which refers to the land that the salt contained in the soil affects the normal growth of crops. The saline-alkali land can be divided into light, moderate and severe saline-alkali land, and the essence of its formation is mainly the redistribution of various soluble salts in the horizontal and vertical directions, so that the salt gradually accumulates in the soil surface layer in the salt accumulation area. Therefore, the saline-alkali land is a kind of obstacle land that the excessive enrichment of salt leads to soil degradation. The soil type of the saline-alkali land includes the saline soil and the alkaline soil, and the saline-alkali land is the general term of the soil with the salt content of more than 0.1% and the alkalization degree of more than 15% and less than 20%. The saline-alkali land belongs to the reserve resource of cultivated land. Because the salt contained in the soil of the saline-alkali farmland is very high, it affects the normal growth of crops, and the economic benefit of the saline-alkali farmland for planting traditional crops is low. The salinization of the farmland soil obviously seriously restricts the sustainable use of water and soil resources and the improvement of crop yield. Therefore, the current urgent problem to be solved is to study the scheme and mechanism of the saline-alkali land treatment, to regulate the physical and chemical properties of the soil, to improve the crop yield and to reduce the improvement cost.

[0003] There are various methods for improving the saline-alkali farmland in the prior art. The commonly used methods include the water improvement method, the physical improvement method, the chemical improvement method and the biological improvement method. The water improvement method is to drain the salt through the underground infiltration pipe according to the law of water and salt movement, and to combine the ditch drainage to prevent the salt from returning, but the engineering quantity is large. The physical improvement method is to destroy the soil capillary action and to block the further accumulation of the salt to the surface by leveling the land, adding the soil, pressing the sand, loosening the soil and lifting the field, but the engineering quantity is large and the cost is high. The chemical improvement method is to add the chemical substances to the soil to reduce the pH and the alkalization degree of the soil and to improve the soil structure. The main chemical improvement agents include the gypsum, the phosphogypsum, the desulfurization gypsum, the sulfur, the humic acid, the furfural residue and the like. The chemical improvement agents can achieve very significant improvement effect on the severe saline-alkali land, but the introduced chemical substances further destroy the microbial community structure of the soil and are not conducive to the nutrient absorption of the crops. The biological improvement method mainly uses the microbial fertilizer to improve the soil, which is conducive to the repair of the soil environment and has been widely applied, but the treatment effect is also limited by the saline-alkali environment.

[0004] Therefore, how to improve the saline-alkali farmland and configure the improvement and planting scheme of the saline-alkali farmland for planting the high value-added crops and improve the yield of the crops in the saline-alkali farmland is one of the important ways to improve the economic benefit of the saline-alkali farmland. SUMMARY

[0005] The application provides a saline-alkali farmland improvement method to solve the problems of poor improvement effect, large engineering quantity, high cost, low yield of matched crops and insignificant economic benefits in the prior art.

[0006] Specifically, the application provides a saline-alkali farmland improvement method, which comprises the following steps.

[0007] 1) providing a field soaking treatment, performing field soaking and stirring and field leveling on the saline-alkali farmland to be improved, and simultaneously performing water irrigation or drip irrigation by applying a microbial agent;

[0008] 2) performing a salinity adjustment treatment on the saline-alkali farmland subjected to the field soaking treatment by using an active calcium fertilizer, and the active calcium fertilizer is a silicon-calcium-magnesium fertilizer;

[0009] 3) performing field leveling on the saline-alkali farmland subjected to the salinity adjustment treatment, and planting crops;

[0010] 4) performing field management according to the growth habits of the planted crops; and

[0011] 5) harvesting the crops, and performing post-treatment on the saline-alkali farmland after the harvesting.

[0012] Further improvement, the field management comprises applying an anti-stress foliar fertilizer and an amino acid mother liquor to the crops in the middle and late growth periods of the crops, the amino acid mother liquor is a concentrated solution remaining after removing bacterial protein and purifying amino acids from a fermentation liquor of an amino acid production bacterium, and the use amount of the amino acid mother liquor is 200-800 L / acre.

[0013] Through the above technical solution, the saline-alkali farmland is subjected to the improvement measures of field soaking, salinity adjustment, matched planting, field management and harvesting and post-treatment of the crops, the salinity and alkalinity in the soil are reduced, the effects of salt blocking, water supplementing and fertilizer supplementing are achieved, the soil health degree is improved, the planting scheme of high-value-added crops is matched, the seedling rate, yield and stress resistance of the crops planted on the saline-alkali farmland are effectively improved, the crops of salt-tolerant type or salt-sensitive type can grow smoothly on the saline-alkali farmland, and the utilization rate of the saline-alkali land is improved.

[0014] Further improvement, the amino acid mother liquor is a valine mother liquor, the valine mother liquor is a concentrated solution remaining after removing bacterial protein and purifying valine from a fermentation liquor of a valine production bacterium, and the valine production bacterium is Xanthobacter or Corynebacterium glutamicum.

[0015] Further improvement, the application method of the amino acid mother liquor is as follows: the amino acid mother liquor is filled in an application tank, is diluted 1000 times by combining with irrigation water, and is applied to the soil environment of the root zone of the crops.

[0016] In the technical scheme, the valine mother liquor contains other small amounts of by-products such as alanine and isoleucine produced by microbial fermentation in addition to valine. Using the valine mother liquor to improve the soil environment of saline-alkali land not only reduces resource waste and consumption, but also reduces pollution discharge and sewage treatment capacity, and provides crops with a variety of nutrients, which helps to improve crop yield, realizes comprehensive utilization of valine fermentation products, and improves the comprehensive benefits of valine fermentation products. The application of the valine mother liquor is not limited to the middle and late stages of crop growth, and can also be applied to saline-alkali soil before sowing, which is beneficial to improve the field germination rate and emergence rate of crops and improve the flavor of crops.

[0017] Further improvement, the step of bubble field processing is: the saline-alkali farmland to be improved is irrigated and the bubble field is 2-3 times, the water volume of each bubble field is 5-8 cm water layer height above the soil surface, each bubble field is 2-5 days, and the last day of each bubble field is stirred and the stirring depth is 15-20 cm, and the soil is settled for 2-3 days after each stirring and settling, and then the water is drained and new water is irrigated for the next bubble field.

[0018] In the technical scheme, the method of irrigating and bubble field and stirring and field is used, which can make the salt and alkali in the surface soil fully dissolved in water and discharged from the farmland. At the same time of irrigating and bubble field, the microbial agent is used to improve the farmland, which can not only quickly reduce the pH value of the soil through acid-base neutralization, but also help the soil to form a granular structure through metabolic activity, increase the soil permeability, improve the structure and tillage of the soil, provide healthy growth conditions for crops, quickly and effectively break the soil obstacles, restore the soil health, and improve the stress resistance of crops.

[0019] Further improvement, the microbial agent in the bubble field processing is irrigated or drip irrigated with water each time the water is irrigated, and the usage is 2-4 kg / acre; the microbial agent includes bacillus subtilis and bacillus pumilus FM4B, and the number of live bacteria is 2-5 billion / mL; the ratio of the number of live bacteria of bacillus subtilis and bacillus pumilus FM4B in the microbial agent is 1:1-5.

[0020] In the technical scheme, the bacillus subtilis and bacillus pumilus FM4B in the microbial agent can quickly increase the number of beneficial biological bacteria in the soil after use, and their metabolic activity can enhance the soil granular structure and stimulate the growth of crop roots. In addition, bacillus pumilus FM4B can inhibit the spread of soil-borne diseases such as fusarium pathogens, and can greatly improve the field emergence rate of crops and reduce the use of chemical pesticides.

[0021] Further improvement, the step of adjusting salinity treatment is: all the water in the bubble field treatment is discharged, then the active calcium fertilizer is uniformly mixed with the surface layer of the saline-alkali farmland, and then the film is covered on the soil to keep it moist for 1-3 days, and then the surface layer is leached; the thickness of the surface layer is 5-15 cm.

[0022] In the prior art, phosphogypsum or desulfurization gypsum is usually used to mix with the surface layer, which can improve the alkalinity of part of the soil, but also forms a large amount of insoluble calcium salt such as calcium sulfate deposited in the soil, which is not conducive to the nutrient absorption of crops and has a certain negative impact on the quality of crop products. Therefore, by applying active calcium fertilizer which can be absorbed by crops, combined with film mulching and leaching measures, the harmful components such as heavy metals and chloride ions deposited in the soil are reduced, the water retention of the soil is increased, and the salt content and conductivity of the farmland soil are effectively reduced.

[0023] In the above technical solution, the active calcium fertilizer is used to adjust the salinity, which can reduce the soil conductivity of the saline-alkali farmland, change the sodium clay into calcium clay, and remove the harmful ions such as sodium ions in the soil through leaching, so that the content of sodium ions in the soil is reduced by more than 50%, the pH value of the soil is reduced, and the formation of soil aggregate structure is promoted, the permeability of the soil is increased, the use amount is small, and the residual active calcium can be directly absorbed by crops. At the same time, it will not cause the deposition of heavy metals and chloride ions in the soil, which can effectively improve the saline-alkali soil and is economic and environmentally friendly.

[0024] Further improvement, the use method of the active calcium fertilizer is to dilute 500-1000 times and spray; the use amount of the active calcium fertilizer is 1-3 g / kg for light saline-alkali soil, 3-6 g / kg for moderate saline-alkali soil, and 6-10 g / kg for heavy saline-alkali soil. The active calcium fertilizer is convenient to use, and the soil can quickly absorb it after spraying. A large amount of active free calcium, silicon and magnesium ions can react with carbonate and bicarbonate in saline-alkali soil to form calcium salt, which can quickly replace sodium ions in the soil. Sodium ions are washed away by leaching, reducing the alkalinity of the soil. The residual active ions after application can also be directly absorbed by crops, without causing environmental pollution.

[0025] Further improvement, before planting crops, base fertilizer is applied to the soil, the base fertilizer is at least one of chemical fertilizer and compound microbial fertilizer; the compound microbial fertilizer contains bacillus pumilus, and the viable count of the compound microorganism is 500-700 million / gram, and the use amount is 80-85 kg / acre; the composition and use amount of the chemical fertilizer are: urea 20 kg / acre, diammonium phosphate 20 kg / acre, and potassium sulfate 5 kg / acre.

[0026] In the above technical solution, the base fertilizer can supplement the important mineral elements carried out by the previous crop, after the base fertilizer enters the soil, the growth of the microorganism in the soil is promoted, the stable aggregate structure of the soil is formed rapidly, and a large amount of nutrient substances are provided for the crop, and the soil fertility is improved, and the material guarantee for the continuous high yield and high quality of the crop is provided.

[0027] Further improvement, the harvesting includes forage storage harvesting, forage harvesting or product harvesting.

[0028] Further improvement, the post-processing operation is that after the crop is harvested, the amino acid mother liquor during the crop management is supplemented into the soil of the saline-alkali farmland, the supplementing amount of the amino acid mother liquor is 500-800L / mu, and after being diluted by 1000 times, it is sprayed or flood irrigation. After the crop is harvested, the valine mother liquor is applied to the soil, the acid substances in the amino acid mother liquor are used to realize the improvement and treatment of the saline-alkali land, the nutrient substances in the valine mother liquor are rich in types, the total nitrogen content of the soil is improved, the pH value and the total salt content of the soil are reduced, and the crop germination and growth are promoted.

[0029] Further improvement, the above improvement method can be used for the saline-alkali farmland with a salt content of not less than 3 ‰ and an alkalization degree of not less than 15 %, and is especially suitable for the saline-alkali farmland in the Hetao region. After the improvement method is used for the saline-alkali farmland, the matched crop can produce products with high yield, high quality, good storage, and sufficient flavor. Through the measures of field soaking, salt adjustment, matched planting, crop field management, harvesting and post-processing, the saline-alkali farmland is improved, the soil health degree is improved, the crops of salt-alkali tolerant type or salt-alkali sensitive type can grow smoothly on the saline-alkali farmland, and the yield is also significantly improved.

[0030] The saline-alkali farmland improvement method provided by the application has the following beneficial effects compared with the prior art.

[0031] 1) The improvement method uses a biological-chemical-physical combined method to reduce the salinity and alkalinity of the soil of the saline-alkali farmland, and when used for improving the saline-alkali farmland, the method can effectively block salt, supplement water and fertilizer, reduce the salt-alkali stress on the crop, and match the planting scheme of the high-value-added crop, so that the crop cultivation protection measures can be realized, the crop planting emergence rate and yield of the saline-alkali farmland can be effectively improved, the amount of owned farmland can be increased, and the utilization rate of the saline-alkali land can be improved.

[0032] 2) In the method, the microbial agent, the active calcium fertilizer and the amino acid mother liquor are used in combination to reduce the alkalinity of the soil, reduce the salt content, change the structure and physicochemical properties of the soil, increase the types of beneficial microorganisms and soil nutrients in the soil, and improve the soil fertility; at the same time, the anti-stress foliar fertilizer is used to enhance the stress resistance of the crop and promote the growth of the crop, so that the yield of the crop is improved and the stress resistance of the crop is enhanced.

[0033] 3) The effect of the improved method lasts long, improves the saline-alkali farmland soil without affecting the continuous planting of crops, effectively improves the soil quality and crop yield, improves the soil fertility and the buffering capacity to salt, alkali and harmful ions, is a protective improvement combined with cultivation, and can be applied to the planting of salt-tolerant crops and crops with poor salt tolerance but high added value. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0035] Figure 1 It is a single-dish comparison chart of sunflowers in the improved group 2 and the control group 2 in Example 5.

[0036] Figure 2 It is a comparison chart of the effects of different methods on the total salt content and the alkali degree of farmland in Example 5.

[0037] Figure 3 It is a comparison chart of sorghum ears in the improved group 2 and the control group 1 in Example 6.

[0038] Figure 4 It is a comparison chart of corn cobs in the improved group 1 and the control group 1 in Example 7. DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort also belong to the protection scope of the present application.

[0040] In the following examples, the test materials and reagents used, unless otherwise specified, can be obtained from commercial channels. If the specific technology or condition is not specified in the examples, it can be carried out according to the technology or condition described in the literature in the art or according to the product instruction.

[0041] In the specific embodiments of the present application, the valine production bacteria used are Corynebacterium glutamicum (purchased from China Industrial Microbial Strain Preservation and Management Center, strain number: CICC 20887).

[0042] In the specific embodiment of the present application, the improved method is tested in Hetao region for rapid improvement and quality improvement and yield increase of saline-alkali land.

[0043] In one specific embodiment of the present application, a saline-alkali land improvement method is provided, comprising the following steps:

[0044] 1) Field soaking treatment: the saline-alkali land to be improved is irrigated and soaked, the soaking frequency is 2-3 times, the water layer height above the soil surface is 5-8 cm each time, the soaking time is 2-5 days each time, and the last day of each soaking is followed by slurry stirring and field leveling, the slurry stirring depth is 15-20 cm, the slurry stirring and field leveling is followed by 2-3 days of sedimentation, then the water is drained and new water is irrigated for the next soaking. During each irrigation and soaking, microbial inoculant is used for water irrigation or drip irrigation of the saline-alkali land.

[0045] Preferably, during the sedimentation period after each slurry stirring and field leveling, the water layer height above the soil surface is maintained at 4-7 cm and cannot be dry. The pH value of the microbial inoculant is not higher than 4.3.

[0046] 2) Salinity adjustment: active calcium fertilizer is used to improve the soil. Specifically, the water used for field soaking treatment is drained, then the active calcium fertilizer is uniformly mixed with the topsoil layer of the saline-alkali land, and then the soil is covered with film and kept moist for 1-3 days, and then the topsoil layer is treated by leaching, the thickness of the topsoil layer is 5-15 cm.

[0047] Preferably, the active calcium fertilizer is silicon calcium magnesium fertilizer, and the pH value is 5.5-6.0.

[0048] Further, for moderate or severe saline-alkali land, when adjusting the salinity, dilute and spray an inorganic acid solution together with the active calcium fertilizer, the inorganic acid content in the inorganic acid solution is 0.5-2 wt%, and the inorganic acid is one of hydrochloric acid, sulfuric acid and nitric acid. The use amount of the inorganic acid solution is 50-70 mL per mu. The addition of the inorganic acid solution when adjusting the salinity of the topsoil layer with the active calcium fertilizer can improve the saline-alkali land with different degrees of salt damage, especially for reducing the alkalinity of moderate and severe saline-alkali land.

[0049] Further preferably, after the leaching treatment, amino acid mother liquor is applied to the topsoil layer, which is consistent with the amino acid mother liquor applied during the middle and late growth stages of crops. More preferably, the amino acid mother liquor is valine mother liquor. The application amount of the above-mentioned amino acid mother liquor is 200-400 L per mu. The application of the amino acid mother liquor to the saline-alkali soil before sowing of crops is beneficial to improve the field germination rate and emergence rate of crops and improve the flavor of crops.

[0050] 3) Matching planting: according to the crops to be planted, the soil is prepared, after the preparation is completed, base fertilizer is applied to the soil, and then the crops are planted according to the habits of the crops to be planted. The base fertilizer is at least one of chemical fertilizer and compound microbial fertilizer. The compound microbial fertilizer contains Bacillus brevis, and the viable count of the compound microorganism is 5-7 billion / gram, and the usage amount is 80-85 kg / acre. The composition and usage amount of the chemical fertilizer are: urea 20 kg / acre, diammonium phosphate 20 kg / acre, and potassium sulfate 5 kg / acre.

[0051] Preferably, examples of the preparation of the soil include, but are not limited to, making ridges, making beds, flat work, and making ridges. Examples of crops include, but are not limited to, sunflowers, peppers, sorghum, Chinese cabbage, corn, tomatoes, licorice, and honeydew melon.

[0052] 4) Crop field management: according to the growth habits of the crops planted, the field is managed, the soil is supplemented when the soil condition of the crops is not good, the water is drained when there is too much precipitation, and the stress-resistant foliar fertilizer and the amino acid mother liquor are applied to the crops in the middle and late growth periods of the crops. In the middle and late growth periods of the crops, the stress-resistant foliar fertilizer is used to improve the osmotic regulation ability of the crops and alleviate the salt stress. The amino acid mother liquor is an acidic substance, and has high nitrogen content, phosphorus content and amino acid content. In view of the defects of high pH value, high total salt content and low organic matter content of the saline-alkali soil, the amino acid mother liquor is used for topdressing, which can achieve the effects of saline-alkali soil treatment and promoting the healthy growth of crops, and is beneficial to the yield and production of crops.

[0053] Preferably, the usage amount of the stress-resistant foliar fertilizer is 50-60 mL / acre, and the stress-resistant foliar fertilizer is sprayed after being diluted by 1000 times.

[0054] Preferably, the valine content in the valine mother liquor is not less than 40 g / L; more preferably, the valine content is 40-50 g / L. And, the free amino acid content in the valine mother liquor is 65-80%.

[0055] More specifically, the preparation method of the valine mother liquor is as follows: the fermentation broth of the valine production strain is sterilized, then the fermentation broth is acidified to reduce the pH value to 4.5-5.5, then the bacterial protein is removed by ceramic membrane filtration to obtain a filtered clear liquid; then the filtered clear liquid is concentrated under reduced pressure to obtain a valine crude product and a valine mother liquor. The sterilization operation condition is: sterilization at 80-100℃ for 10-30 min. The concentration under reduced pressure is carried out at 60-100℃, and the concentration multiple is 10-20 times. The fermentation broth is acidified by phosphoric acid. The ceramic membrane filtration uses a ceramic membrane with a pore size of 10-75 nm, an inlet membrane pressure of 0.1-0.4 MPa, and a flux of 4-7 L / min / m 2The fermentation liquid is flocculated and denatured by phosphoric acid to remove water-soluble proteins in the fermentation liquid, so that the bacterial cells and most of the proteins are removed in the membrane filtration process, and the separation of valine and impurity amino acids is facilitated, the impurity amino acids are maximally reserved in the valine mother liquor, the phosphoric acid can avoid the damage of strong acids such as hydrochloric acid and sulfuric acid, and can provide phosphorus elements for crops, and can help to improve the quality of crops.

[0056] The preparation method of the fermentation liquid of the valine-producing bacteria is as follows: the secondary seed liquid of the valine-producing bacteria is inoculated into the fermentation medium at an inoculation amount of 1-10%, the fermentation temperature is 30-35°C, the fermentation is carried out until the OD value is less than 3, the antioxidant sodium erythorbate is added, and the fermentation is continued until the glucose content in the fermentation liquid is ≤2g / L, and then the fermentation is stopped, thereby obtaining the fermentation liquid of the valine-producing bacteria. The activation of the valine-producing bacteria, the culture of the primary seed liquid and the culture of the secondary seed liquid are all conventional fermentation operations, which can be completed by those skilled in the art, and will not be described here.

[0057] 5) Harvesting and post-processing: the crops are harvested, and after harvesting, the amino acid mother liquor during crop management is supplemented into the soil of the saline-alkali farmland. Preferably, the amino acid mother liquor is a valine mother liquor. The supplementing amount of the above-mentioned amino acid mother liquor is 500-800L / acre.

[0058] In another specific embodiment of the present application, a method for planting crops on saline-alkali farmland is provided, which comprises the following steps:

[0059] 1) Improvement and pretreatment of saline-alkali farmland: the saline-alkali farmland is sequentially subjected to ponding treatment and salt adjustment treatment.

[0060] The specific steps of the ponding treatment are as follows: the saline-alkali farmland to be improved is subjected to ponding, the water layer height above the soil surface is 5-8cm, the ponding time is 2-5 days, and the last day of each ponding is subjected to stirring and soil leveling, the stirring depth is 15-20cm, the soil is precipitated for 2-3 days after each stirring and soil leveling, then the water is drained and new water is poured for the next ponding. During the precipitation period after each stirring and soil leveling, the water layer height above the soil surface should be maintained at 4-7cm, and cannot be dry. During each ponding, microbial inoculum is used for irrigation or drip irrigation with water, and the use amount of the microbial inoculum is 2-4kg / acre. The microbial inoculum comprises Bacillus subtilis and Brevibacillus brevis FM4B, and the viable bacterial count is 2-5×10 8 / mL. The ratio of the viable bacterial count of Bacillus subtilis to that of Brevibacillus brevis FM4B in the microbial inoculum is 1:1-5. The pH value of the microbial inoculum is not higher than 4.3.

[0061] The specific steps of the salt adjustment treatment are as follows: all the water used for the soaking treatment is drained, then the active calcium fertilizer is uniformly mixed with the surface layer of the saline-alkali soil, and then the soil is covered with a film and kept moist for 1-3 days, and then the surface layer is treated by leaching, and the thickness of the surface layer is 5-15 cm. The active calcium fertilizer is a silicon calcium magnesium fertilizer, and the pH value is 5.5-6.0. The use method of the active calcium fertilizer is to be sprayed after being diluted by 500-1000 times.

[0062] Preferably, after the leaching treatment is completed, amino acid mother liquor is applied to the surface layer, and the amino acid mother liquor is consistent with the amino acid mother liquor applied during the middle and late growth periods of the crops. More preferably, the amino acid mother liquor is a valine mother liquor.

[0063] 2) Crop planting: according to the crops to be planted, the soil is prepared, after the preparation is completed, base fertilizer is applied to the soil, and then the crops are planted according to the habits of the crops to be planted. The base fertilizer is at least one of chemical fertilizer and compound microbial fertilizer.

[0064] The compound microbial fertilizer contains Bacillus pumilus, and the viable count of the compound microorganism is 5-7 billion / gram, and the usage amount is 80-85 kg / acre. The composition and usage amount of the chemical fertilizer are: urea 20 kg / acre, diammonium phosphate 20 kg / acre, and potassium sulfate 5 kg / acre.

[0065] Examples of the soil preparation include but are not limited to ridging, bed making, flat planting, and ridge making. Examples of the crops include but are not limited to sunflower, pepper, sorghum, Chinese cabbage, corn, tomato, licorice, and honeydew melon.

[0066] 3) Field management: field management is performed according to the growth habits of the planted crops, soil moisture is supplemented when the soil moisture of the crops is poor, drainage is performed when there is excessive rainfall, and stress resistance foliar fertilizer and amino acid mother liquor are applied to the crops during the middle and late growth periods of the crops. The usage amount of the stress resistance foliar fertilizer is 50-60 mL / acre, and the stress resistance foliar fertilizer is sprayed after being diluted by 1000 times. The above-mentioned amino acid mother liquor is a concentrated liquid obtained by removing bacterial protein and purifying amino acid from the fermentation broth of an amino acid production strain. The usage amount of the amino acid mother liquor is 200-800 L / acre. The application method of the amino acid mother liquor is: the amino acid mother liquor is loaded into an application tank, diluted by 1000 times by combining with irrigation water, and then applied to the soil environment of the root zone of the planted crops.

[0067] 4) Harvesting: the crops are harvested, and the harvesting includes green storage harvesting as feed, harvesting as feed, or harvesting as products.

[0068] 5) Post-treatment: after the crops are harvested, the amino acid mother liquor during the crop management period is supplemented to the soil of the saline-alkali land. Preferably, the amino acid mother liquor is a valine mother liquor. The supplemented amount of the amino acid mother liquor is 500-800 L / acre, and the amino acid mother liquor is sprayed or flood irrigated after being diluted by 1000 times.

[0069] In another specific embodiment of the present application, there is provided a use of a valine mother liquor in improving saline-alkali farmland, wherein the valine mother liquor is used at least in one of the following periods: before planting crops, during the growth of crops, at the late growth stage of crops, and after harvesting crops.

[0070] The valine mother liquor is applied to the soil of the saline-alkali farmland. The use amount of the valine mother liquor is 200-800 L / acre.

[0071] The specific application method of the valine mother liquor is as follows: the valine mother liquor is loaded into an application tank, diluted 1000 times by combining with irrigation water, and then applied to the soil environment of the root zone of the crops. The content of valine in the valine mother liquor is not less than 40 g / L, preferably 40-50 g / L; and the content of free amino acids in the valine mother liquor is 65-80%.

[0072] Before planting the crops, at least one of the following operations is further included: soaking the seeds with the valine mother liquor, and soaking the seedlings with the valine mother liquor.

[0073] The use of the valine mother liquor in improving the saline-alkali farmland includes the following steps: according to the crops to be planted, the soil is prepared, after the preparation is completed, the valine mother liquor is applied to the soil, and then the crops are planted according to the habits of the crops to be planted.

[0074] In addition to valine, the valine mother liquor also contains other small amounts of by-products such as alanine and isoleucine produced by microbial fermentation. When the valine mother liquor is used to improve the saline-alkali farmland, it can optimize the soil, make the beneficial microorganisms reproduce normally, promote the healthy growth of plants, increase the yield, improve the taste of crops, strengthen the immunity of crops, and improve the disease resistance and stress resistance of crops. Therefore, when the valine mother liquor is used to improve the saline-alkali farmland, it can achieve the effects of improving the saline-alkali land and promoting the healthy growth of crops, which is beneficial to the yield and production of crops.

[0075] The present application will be further described in detail in conjunction with the following examples. However, it should be understood that the examples are for illustrative purposes only and are not intended to limit the scope of the present application.

[0076] Example 1:

[0077] A method for improving saline-alkali farmland includes the following steps:

[0078] 1) soaking treatment: the saline-alkali farmland to be improved is soaked with water, the soaking frequency is 2 times, the water amount of each soaking is 5 cm water layer height above the soil surface, each soaking lasts for 3 days, and the last day of each soaking is for stirring and ploughing, the stirring depth is 15 cm, after each stirring and ploughing, the soil is deposited for 2 days, then the water is drained and new water is poured for the next soaking. During the deposition period after each stirring and ploughing, the water layer height above the soil surface is kept at 4 cm, and cannot be dry. During each soaking, microbial agent is used for irrigation or drip irrigation of the saline-alkali farmland, the use amount of the microbial agent is 2 kg / mu. The microbial agent contains bacillus subtilis and bacillus pumilus FM4B, and the viable count is 200 million / mL. The ratio of the viable count of bacillus subtilis to bacillus pumilus FM4B in the microbial agent is 1:1.5. The pH value of the microbial agent is not higher than 4.3.

[0079] 2) adjusting salinity: all the water used for soaking is drained, then the active calcium fertilizer is uniformly mixed with the topsoil layer of the saline-alkali farmland, and then the soil is covered and kept moist for 2 days, and then the topsoil layer is treated by leaching, the thickness of the topsoil layer is 10 cm. The active calcium fertilizer is silicon calcium magnesium fertilizer, and the pH value is 5.5-6.0. The use method of the active calcium fertilizer is to be sprayed after being diluted by 1000 times.

[0080] When the moderate or severe saline-alkali land is adjusted for salinity, an inorganic acid solution is diluted and sprayed together with the active calcium fertilizer, the inorganic acid content in the inorganic acid solution is 2wt%, the inorganic acid is hydrochloric acid, and the use amount of the inorganic acid solution is 50 mL / mu.

[0081] 3) matching planting: according to the crops to be planted, the soil is prepared, after the soil preparation, base fertilizer is applied to the soil, and then the crops are planted according to the habits of the crops to be planted. The base fertilizer is chemical fertilizer, and the composition and use amount of the chemical fertilizer are: urea (containing N 46%) 20 kg / mu, diammonium phosphate (containing N 18%, containing P2O5 46%) 20 kg / mu, potassium sulfate (containing K2O 50%) 5 kg / mu. The soil preparation includes but is not limited to making ridges, making beds, flat planting, and making ridges, etc. The crops include but are not limited to sunflower, pepper, sorghum, Chinese cabbage, corn, tomato, licorice, and honeydew melon, etc.

[0082] 4) crop field management: according to the growth habits of the crops, the field is managed, when the crop conditions are not good, the soil is supplemented, when the precipitation is too much, the water is drained, and during the middle and late growth periods of the crops, resistance foliar fertilizer and amino acid mother liquor are applied to the crops. The use amount of the resistance foliar fertilizer is 50 mL / mu, and it is sprayed after being diluted by 1000 times.

[0083] The amino acid mother liquor is a valine mother liquor, and the use amount of the valine mother liquor is 600 L / mu. The application method is as follows: the valine mother liquor is loaded into an application tank, combined with irrigation water to dilute 1000 times, and then applied to the soil environment of the root zone of the crop planting. The content of valine in the valine mother liquor is 42 g / L. Moreover, the content of free amino acid in the valine mother liquor is 69%.

[0084] 5) Harvesting and post-processing: the crops are harvested, including forage storage harvesting, forage harvesting or product harvesting. After the crop is harvested, the valine mother liquor during crop management is supplemented into the soil of the saline-alkali farmland, and the supplemented amount of the valine mother liquor is 500 L / mu, which is sprayed or flood irrigated after being diluted by 1000 times. Example 2:

[0085] A saline-alkali farmland improvement method, based on example 1, further comprises:

[0086] In step 2), after the leaching treatment is completed, the valine mother liquor is applied to the topsoil layer, and the application amount of the valine mother liquor is 200 L / mu.

[0087] In step 3), base fertilizer is applied to the soil, and the base fertilizer is a compound microbial fertilizer, the compound microbial fertilizer contains Bacillus pumilus, and the viable count of the compound microorganism is 500 million / gram, and the use amount is 80 kg / mu. Example 3:

[0088] A method for planting crops on saline-alkali farmland, comprising the following steps:

[0089] 1) Improvement pretreatment of saline-alkali farmland: the saline-alkali farmland is sequentially subjected to ponding treatment and salt adjustment treatment.

[0090] The specific steps of the ponding treatment are as follows: the saline-alkali farmland to be improved is subjected to ponding, the number of ponding is 3 times, the water amount of each ponding is to have a water layer height of 5 cm above the soil surface, each ponding lasts for 3 days, and at the end of each ponding, slurry stirring and field leveling are performed, the stirring depth of slurry stirring and field leveling is 17 cm, after each slurry stirring and field leveling, the soil is deposited for 2 days, then the water is drained and new water is poured for the next ponding. During the deposition period after each slurry stirring and field leveling, the water layer height above the soil surface should be maintained at 4 cm, and cannot be dry.

[0091] During each ponding, microbial agent is used for water irrigation or drip irrigation of the saline-alkali farmland, and the use amount of the microbial agent is 4 kg / mu. The microbial agent contains Bacillus subtilis and Bacillus pumilus FM4B, and the viable count is 250 million / mL. The ratio of the viable count of Bacillus subtilis and Bacillus pumilus FM4B in the microbial agent is 1:2.

[0092] The specific steps of the salt adjustment treatment are as follows: all the water in the soaking field treatment is discharged, then the active calcium fertilizer is uniformly mixed with the surface soil layer of the saline-alkali farmland, and then the film mulching and moisture preservation are performed on the soil for 2 days, and then the surface soil layer is subjected to leaching treatment, and the thickness of the surface soil layer is 5 cm. The active calcium fertilizer is a silicon calcium magnesium fertilizer, and the pH value is 5.5-6.0. The use method of the active calcium fertilizer is to be sprayed after being diluted by 1000 times.

[0093] 2) Crop planting: according to the crops to be planted, the soil is prepared, after the preparation is completed, base fertilizer is applied to the soil, and then the crops are planted according to the habits of the crops to be planted. The base fertilizer is chemical fertilizer, and the composition and the use amount of the chemical fertilizer are as follows: urea (containing N 46%) 20 kg / mu, diammonium phosphate (containing N 18%, containing P2O5 46%) 20 kg / mu, potassium sulfate (containing K2O 50%) 5 kg / mu.

[0094] 3) Field management: according to the growth habits of the crops planted, field management is performed, when the crop moisture condition is not good, the soil moisture is supplemented, when the precipitation is too much, the water is drained, and the anti-stress foliar fertilizer and the amino acid mother liquor are applied to the crops in the middle and late growth periods of the crops. The use amount of the anti-stress foliar fertilizer is 50 mL / mu, and the spraying is performed after being diluted by 1000 times. The above-mentioned amino acid mother liquor is valine mother liquor, and the use amount is 500 L / mu. The application method is as follows: the valine mother liquor is loaded into an application tank, combined with irrigation water, diluted by 1000 times, and applied to the soil environment of the root zone of the crop planting.

[0095] 4) Harvesting: the crops are harvested, and the harvesting includes forage green storage harvesting, forage harvesting or product harvesting.

[0096] 5) Post-treatment: after the crops are harvested, the amino acid mother liquor during the crop management is supplemented into the soil of the saline-alkali farmland, the above-mentioned amino acid mother liquor is valine mother liquor, the supplemented amount is 500 L / mu, and the spraying or flooding irrigation is performed after being diluted by 1000 times. Example 4:

[0097] The use of a valine mother liquor in improving saline-alkali farmland, the application steps comprising: according to the crops to be planted, the soil is prepared, after the preparation is completed, the valine mother liquor is applied to the soil, and then the crops are planted according to the habits of the crops to be planted. The use amount of the above-mentioned valine mother liquor is 600 L / mu, and the application method is as follows: the valine mother liquor is loaded into an application tank, combined with irrigation water, diluted by 1000 times, and applied to the soil environment of the root zone of the crop planting. The content of valine in the above-mentioned valine mother liquor is 42 g / L; and the content of free amino acid in the valine mother liquor is 69%. Example 5:

[0098] Sunflower planting test: the sunflower variety is edible sunflower variety SH361.

[0099] 5.1: The test site is located in Ganzhaomiao Test Base of Bayannur Agricultural and Pastoral Science Institute. The altitude is 1035 m, the average annual temperature is 3.7-7.6℃, the sunshine hours are 3100-3300h, the frost-free period is 126d, the average annual precipitation is 188mm, the evaporation is 2030-3180mm, and it is a typical continental monsoon climate in the Hetao Irrigation Area. The test site is flat, convenient for irrigation and drainage, and after harvesting, irrigation is carried out in late October after fall plowing to preserve soil moisture. Sunflower is planted in large and small rows, with a large row of 100 cm, a small row of 40 cm, a plant spacing of 60 cm, and 56 plants per row, and the plots are separated by ridges.

[0100] Test group setting: Select the same area of the test site in the same large area, and set it as modified group 1, modified group 2, control group 1 and control group 2, and the area of each group is 328m 2 (long 33.5m, wide 9.8m). The modified group 1 is cultivated and planted according to example 1. The modified group 2 is cultivated and planted according to example 4. The control group 1 is cultivated and planted according to example 1, but when the crop field management is carried out, the stress-resistant foliar fertilizer is applied to the crop in the middle and late growth stages, and the valine mother liquor is not applied. The control group 2 is cultivated and planted according to example 4, but the chemical fertilizer (the composition and amount of the chemical fertilizer are consistent with example 1) is applied to the soil, and the valine mother liquor is not applied.

[0101] In this example, the composite microbial fertilizer is the Fengman Dadi composite microbial fertilizer purchased from Bayannur Huaheng Biotechnology Co., Ltd. The stress-resistant foliar fertilizer is the Fenglibao amino acid water-soluble fertilizer purchased from Qinhuangdao Fengrui Biological Technology Development Co., Ltd. In the valine mother liquor, the valine content is 42g / L, the aspartic acid content is 5g / L, the threonine content is 1g / L, the glutamic acid content is 10g / L, the glycine content is 3g / L, the alanine content is 5g / L, the tyrosine content is 1g / L, the phenylalanine content is 1g / L, the arginine content is 1g / L, the free amino acid content is 69%, and the pH value is 5.1 (detection method NY1429-2010).

[0102] 5.2: Test main indicators and methods

[0103] (1) Soil indicators: Before sowing and land preparation, five-point sampling method is used to collect 0-20cm soil samples to measure soil organic matter, total nitrogen, available phosphorus, available potassium, total salt, pH value and alkalization degree. After crop harvesting, 0-20cm soil samples are collected to measure soil organic matter, total nitrogen, available phosphorus, available potassium, total salt, pH value and alkalization degree. Soil samples are measured by Bayannur Agricultural and Pastoral Science Institute.

[0104] (2) Crop indicators:

[0105] Growth and development traits: sunflower survival rate in seedling stage. Height, stem diameter, disc diameter, and chlorophyll SPAD value of 10 consecutive sunflowers in each group were investigated in mature stage.

[0106] Yield: yield was measured in 3 typical areas in harvest stage, 10 meters of double film (14 meters of sunflower) were continuously sampled in each area, and the sunflower yield was calculated by weighing the naturally dried seeds. 2

[0107] (3) Sunflower quality (taste) index: sunflower seeds in each group were randomly selected, and 30 taste testers were randomly selected for taste investigation, scoring 1-10 points (1 point for the worst, 10 points for the best), and taking the average value.

[0108] 5.3: Test results and analysis

[0109] (1) Effect of different methods on sunflower growth

[0110] Table 1

[0111]

[0112] By comparing the results of improved group 1 and control group 1, improved group 2 and control group 2 in table 1, it was found that the improved group 1 had the best effect on the growth of sunflower, and the use of valine mother liquor was beneficial to improve the yield of sunflower, increase the survival rate of sunflower in saline-alkali environment, increase the stem diameter and disc diameter of sunflower, reduce the probability of lodging by reducing the plant height, delay leaf senescence by increasing chlorophyll content (SPAD value of chlorophyll is positively correlated with chlorophyll content), prolong the photosynthesis time and improve the photosynthesis rate, increase the dry matter accumulation, and the flavor of the group treated with valine mother liquor is better.

[0113] Figure 1 The single disc of sunflower in improved group 2 and control group 2 was compared. It was found from the figure that the single disc diameter of sunflower treated with valine mother liquor was larger, which indicated that valine mother liquor was helpful to increase the single disc grain number and grain weight, and improve the yield of sunflower.

[0114] (2) Effect of different methods on physical and chemical properties of cultivated soil

[0115] Table 2

[0116]

[0117] Figure 2 ​The effects of different methods on the total salt content and alkali degree of the cultivated land are compared in the following figures. Before the test, the total salt content of the cultivated land was 3.0 g / kg, and the alkali degree was 16.3%. After the test, the total salt content of the cultivated land in the improvement group 1 was 1.2 g / kg, and the alkali degree was 12.7%. The total salt content of the cultivated land in the improvement group 2 was 1.5 g / kg, and the alkali degree was 13.8%. The total salt content of the cultivated land in the control group 1 was 1.4 g / kg, and the alkali degree was 13.3%. The total salt content of the cultivated land in the control group 2 was 1.9 g / kg, and the alkali degree was 15.9%.

[0118] It is found by comparing the results of the improvement group 1 and the control group 1, and the improvement group 2 and the control group 2 in Table 2 that the improvement group 1, the control group 1 and the improvement group 2 can significantly improve the total nitrogen content of the soil, activate the phosphorus nutrient to a certain extent, reduce the soil pH value and the total salt content, and also reduce the alkali degree of the cultivated land soil. Among them, using only the valine mother liquor for improvement in the improvement group 2 can also significantly reduce the salinization degree of the cultivated land, which expands the use of the valine mother liquor. Example 6

[0119] Sorghum planting test

[0120] 6.1: The test site is located in the Ganzhaomiao test base of the Bayannur Agricultural and Pastoral Science Institute. The soil is prepared according to the growth habit of sorghum and the corresponding test cultivated land is set up. The fertilizers such as bacterial fertilizer, foliar fertilizer, and valine mother liquor used are consistent with those in Example 5.

[0121] Test group setting: Select the same area of test land in the same area and set it as the improvement group 1, the improvement group 2 and the control group 1. The improvement group 1 is improved and planted according to Example 1. The improvement group 2 is improved and planted according to Example 4. The control group 1 is improved and planted according to Example 4, but the chemical fertilizer (the composition and amount of use are consistent with those in Example 1) is applied to the soil without applying the valine mother liquor.

[0122] 6.2: Test main indicators and methods

[0123] (1) Soil indicators: Before sowing and soil preparation and after crop harvesting, five-point sampling method is used to collect 0-20 cm soil samples to measure the total salt, pH value and alkali degree of the soil. The soil samples are measured by the Bayannur Agricultural and Pastoral Science Institute.

[0124] (2) Crop indicators: growth and development traits: diameter, chlorophyll SPAD value, plant height, ear length, ear diameter, ear weight.

[0125] 6.3: Test results and analysis

[0126] Table 3

[0127]

[0128] Figure 3 The contrast chart of the ear of sorghum of the improvement group 2 and the control group 1. It is found from the chart that the ear of sorghum treated by the valine mother liquor is fuller and thicker, which shows that the valine mother liquor is helpful to improve the growth traits and yield of sorghum.

[0129] It is found from the results of the improvement group 1, the improvement group 2 and the control group 1 in table 3 that the improvement group 1 has the best effect on the growth of sorghum and the best effect on the improvement of the salinization of farmland soil; the use of the valine mother liquor in the improvement group 2 is beneficial to improve the yield of sorghum and also has a certain effect on the improvement of the salinization of farmland. Example 7

[0130] Corn planting test:

[0131] 7.1: The test site is located in the Ganzhaomiao test base of the Bayannur Institute of Agricultural and Pastoral Science. The soil is prepared according to the growth habit of corn and the corresponding test farmland is set. The fertilizers such as bacterial fertilizer, foliar fertilizer and valine mother liquor used are consistent with those in example 5.

[0132] Test group setting: select the same area of test land in the same area, and set them as the improvement group 1 and the control group 1 respectively. The improvement group 1 is planted according to the farmland improvement in example 4. The control group 1 is planted according to the farmland improvement in example 4, but the chemical fertilizer (the composition and amount of the chemical fertilizer are consistent with those in example 1) is applied to the soil, and the valine mother liquor is not applied.

[0133] 7.2: The test mainly measures the crop indexes: growth and development traits: measure the ear length, ear thickness, ear weight, bare tip length, axis weight and 200 grain weight.

[0134] 7.3: Test results and analysis

[0135] Table 4

[0136]

[0137] Figure 4 The contrast chart of the corn cob of the improvement group 1 and the control group 1. It is found from the chart and the data in table 4 that the corn cob treated by the valine mother liquor is longer and thicker, which shows that the valine mother liquor is helpful to promote the growth and development of the plant and improve the yield of corn and other crops.

[0138] It should be noted that in the present application, the concentration, ratio and the like not specially mentioned are weight concentration, weight ratio and the like, which are the writing habits commonly used by those skilled in the art, so they will not be described in detail in the present application.

[0139] It should be noted that in the present application, the detailed steps of some operations are not described in detail, but belong to the prior art known to those skilled in the art, so they will not be described here.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for improving saline-alkali arable land, characterized in that, include: We provide paddy field treatment, which involves irrigating and soaking saline-alkali farmland that needs improvement, and stirring the soil to prepare the land. At the same time, we apply microbial agents for irrigation or drip irrigation. The salinity of the saline-alkali cultivated land that has undergone the aforementioned paddy field treatment is adjusted by using active calcium fertilizer, wherein the active calcium fertilizer is a silicon-calcium-magnesium fertilizer; The salinity-adjusted farmland is prepared and crops are planted. Field management shall be carried out in accordance with the growth habits of the planted crop; and, The crops were harvested, and the saline-alkali farmland was post-treated after harvesting. The steps of the paddy field treatment are as follows: the saline-alkali farmland that needs to be improved is irrigated and soaked 2-3 times. The amount of water used for each soaking is such that the water layer is 5-8cm above the soil surface. Each soaking lasts 2-5 days. On the last day of each soaking, the paddy field is stirred and prepared. The stirring depth is 15-20cm. After each stirring and preparation, the soil is allowed to settle for 2-3 days. Then the water is drained and fresh water is added for the next soaking. The steps for adjusting salinity are as follows: drain all the water used for soaking the field, then mix the active calcium fertilizer evenly with the topsoil of the saline-alkali cultivated land, cover the soil with a film to retain moisture for 1-3 days, and then rinse the topsoil layer; the thickness of the topsoil layer is 5-15cm. The field management includes applying stress-resistant foliar fertilizer and amino acid stock solution to the crop during the mid- and late-stage growth stages. The amino acid stock solution is a concentrated liquid remaining after removing bacterial protein and purifying amino acids from the fermentation broth of amino acid-producing bacteria. The amount of amino acid stock solution used is 200-800 L / mu. The amount of stress-resistant foliar fertilizer used is 50-60 mL / mu, diluted 1000 times before spraying. The method of applying the amino acid mother liquor is as follows: the amino acid mother liquor is placed in an application tank, diluted 1000 times with irrigation water, and applied to the root zone soil environment of the crop planting area with the water. The amino acid mother liquor is valine mother liquor, which is the concentrated liquid remaining after removing bacterial protein and purifying valine from the fermentation broth of valine-producing bacteria; the valine-producing bacteria are either *Bacillus flavus* or *Corynebacterium glutamicum*. The valine content in the valine mother liquor is not less than 40 g / L, and the free amino acid content in the valine mother liquor is 65-80%.

2. The method for improving saline-alkali farmland according to claim 1, characterized in that, The microbial agent used in the paddy field treatment is applied at a rate of 2-4 kg / mu during each irrigation or drip irrigation. The microbial agent includes Bacillus subtilis and Bacillus brevis FM4B, with a viable count of 200-500 million / mL. The ratio of viable Bacillus subtilis to Bacillus brevis FM4B in the microbial agent is 1:1-5.

3. The method for improving saline-alkali farmland according to claim 1, characterized in that, The active calcium fertilizer is applied by spraying after diluting it 500-1000 times; the dosage of the active calcium fertilizer is 1-3g / kg for mildly saline-alkali land, 3-6g / kg for moderately saline-alkali land, and 6-10g / kg for severely saline-alkali land.

4. The method for improving saline-alkali farmland according to claim 1, characterized in that, Before planting the crops, base fertilizer is applied to the soil. The base fertilizer is at least one of chemical fertilizer and compound microbial fertilizer. The compound microbial fertilizer contains Bacillus shortiflorus, and the number of live microorganisms is 500-700 million / gram. The amount used is 80-85 kg / mu. The composition and amount of the chemical fertilizer are: urea 20 kg / mu, diammonium phosphate 20 kg / mu, and potassium sulfate 5 kg / mu.

5. The method for improving saline-alkali farmland according to claim 1, characterized in that, The harvesting includes harvesting for silage, harvesting as feed, or harvesting as a product.

6. The method for improving saline-alkali farmland according to claim 1 or 5, characterized in that, The post-treatment operation is as follows: after crop harvesting, amino acid stock solution used during crop management is added to the soil of saline-alkali cultivated land; the amount of amino acid stock solution added is 500-800L / mu, diluted 1000 times and then sprayed or flooded.

Images