A biological method for the reclamation of alkaline saline soils

Abstract

The application relates to a biological improvement method for alkaline salinized soil, which comprises any one or more of the following modes: land leveling, land preparation, liquid soil improvement agent application, ridging, planting salt-tolerant pasture, micro-irrigation, applying biological organic nutrient liquid and acidic microbial agent. The application can comprehensively improve the main alkaline salinized soil problems of soil alkalization, nutrient imbalance, salt accumulation and soil hardening caused by secondary salinization, is economic, environment-friendly and low-carbon, simultaneously reduces the amount of chemical fertilizer by 80-100%, realizes the sustainable goals of alkali and salt reduction, fertilizer reduction and efficiency increase, low-carbon and environment-friendly improvement and utilization of saline-alkali soil, and has the advantages of non-toxicity, harmlessness, good improvement effect and no risk to the environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological improvement of saline-alkali soil, and particularly relates to a biological improvement method for alkaline salinization soil. BACKGROUND

[0002] In agricultural production activities, improper management of soil, fertilizer and water, and single planting structure often cause secondary salinization of soil, leading to soil obstacles such as increased soil pH and salt accumulation on the surface. The harm of alkaline salinization soil is as follows: (1) seed germination and growth are inhibited, which seriously affects the emergence rate; (2) soil nutrient imbalance. Long-term planting of a single variety can cause soil nutrient imbalance due to selective absorption by crops; under alkaline conditions, the availability of nutrient elements is reduced, leading to physiological nutrient imbalance in plants, for example, when the soil pH is greater than 8.5, the absorption of nitrogen is reduced, phosphorus is fixed, and the mobility is poor, leading to a decrease in the phosphorus content of soil solution, low solubility of medium elements calcium and magnesium in soil, and difficulty in absorption, and the availability of trace elements iron, boron, manganese, copper, zinc, cobalt and other elements in alkaline soil is greatly reduced, physiological diseases are more serious, and the yield and quality of crops are reduced; (3) soil microbial ecological imbalance. In alkaline salinization soil, many beneficial microorganisms are inactivated due to high salt and alkali, leading to soil microbial ecological imbalance, continuous occurrence of soil-borne diseases and pests or difficult diseases, increasing the difficulty of safe prevention and control of crop diseases and pests, leading to frequent occurrence of diseases and pests, more use of pesticides, poor prevention and control effect, and serious impact on the yield, quality and safety of agricultural products; (4) strong alkaline and saline soil has poor aggregate structure and is hard, which is not conducive to crop emergence and growth.

[0003] Common methods for improving alkaline salinization soil include water conservancy engineering measures, chemical measures and biological measures. Water conservancy engineering measures include salt washing by irrigation, salt removal by drainage, salt compression by water storage, etc. Chemical measures include the application of inorganic compounds such as ferrous sulfate, sulfur powder, ammonium sulfate, ammonium nitrate, potassium dihydrogen phosphate, directional neutralization of alkalinity and application of desulfurized gypsum or phosphogypsum, which can exchange Ca-Na ions, precipitate carbonate and bicarbonate to achieve the purpose of reducing alkalinity. Biological measures include the application of mineral humic acid, the large-scale application of farmyard manure, and the planting of salt-tolerant plants, etc. In actual application, only 1-2 obstacle factors of salinization soil are usually considered, and the measures taken are relatively single, and most of the improvement materials are inorganic components, which have no obvious effect on soil improvement and low actual use efficiency. The use of inorganic compounds such as aluminum sulfate, calcium sulfate and sulfur powder for improvement can cause aluminum toxicity and environmental risk. There are also problems such as high cost and complex operation.

[0004] Therefore, it is urgent to provide a comprehensive improvement method for alkaline salinized soil, which can quickly reduce the salt content of the soil, improve the soil fertility, reduce the amount of chemical fertilizer, promote the growth and development of crops / pasture under salt stress, and produce economic benefits. SUMMARY

[0005] In view of the problems existing in the prior art, the purpose of the present application is to provide a comprehensive, organic and ecological biological improvement technology and method for improving alkaline salinized soil, which can replace chemical fertilizers. The present application has the advantages of being non-toxic, harmless, low-carbon, good improvement effect, and no risk to the environment.

[0006] The technical solution of the present application to solve the above technical problems is as follows:

[0007] The present application provides a biological improvement method for alkaline salinized soil, comprising any one or several of (1) to (7);

[0008] (1) land leveling;

[0009] (2) land preparation;

[0010] (3) applying liquid soil conditioner;

[0011] (4) ridging;

[0012] (5) planting salt-tolerant pasture;

[0013] (6) micro-irrigation;

[0014] (7) applying biological organic nutrient solution and acidophilic microbial agent.

[0015] The beneficial effects of the above technical solution include: land leveling can make the land flat, the water and fertilizer are evenly distributed, and the overall salt and alkali reduction effect is obvious; land preparation such as deep plowing and deep tillage can break the plow pan, break the hardening, increase the soil permeability, and thus improve the efficiency of salt washing and alkali compression; applying liquid soil conditioner can significantly reduce the alkali content, and also improve the soil physical and chemical properties; ridging can break the hardening of the surface soil, increase the water, air, fertilizer and light permeability of the soil, and easily make the leached salt and alkali migrate downward; planting salt-tolerant pasture can absorb the salt content in the soil through the growth of the pasture, reduce the soil salt content, activate the rhizosphere microbial activity and population number through the metabolic activity and secretions of the root system, improve the unbalanced soil microbial ecological environment, and provide rich and high-quality organic matter for the soil and produce economic benefits; water-saving micro-irrigation can quickly reduce the salt content of the plough layer soil; applying acidophilic microbial agent can not only reduce the soil pH, but also promote the seed germination and root growth under salt stress; applying biological organic nutrient solution can replace 80-100% of the amount of inorganic chemical fertilizer.

[0016] The alkali-salinized soil improver of the present application is liquid and multipurpose.

[0017] The liquid soil improver provided by the present application combines the precise micro-irrigation salt washing technology and the planting of salt-tolerant, salt-absorbing and high-protein pasture, and other agricultural technologies for improving saline-alkali soil, and can comprehensively improve the main problems of alkali-salinized soil, such as soil alkalization, nutrient imbalance, salt accumulation, and soil hardening, caused by secondary salinization, and is both economical and environmentally friendly and low-carbon, and at the same time, the amount of alkali and fertilizer used is reduced by 80%-100%, achieving the sustainable goal of improving and utilizing saline-alkali soil with reduced alkali and salt, reduced fertilizer, increased efficiency, low carbon and environmental protection. It has the advantages of good improvement effect and sustainability.

[0018] The bio-organic nutrient solution and the acidic microbial agent are nutrient-rich and meet the nutritional needs of plant growth. They can replace 80%-100% of chemical fertilizers, avoiding the environmental negative effects and affecting the quality of agricultural products caused by the use of large amounts of chemical fertilizers.

[0019] Further, the liquid soil improver includes the bio-organic nutrient solution and the acidic microbial agent.

[0020] The bio-organic nutrient solution and the acidic microbial agent are mixed and applied. The mass ratio of the bio-organic nutrient solution to the acidic microbial agent is 10:1 to 10:3.

[0021] Further, in step (7), the mass ratio of the bio-organic nutrient solution to the acidic microbial agent is 10:2.

[0022] Further, the bio-organic nutrient solution is prepared by micro-aerobic microbial enzymolysis of livestock and poultry manure; and the acidic microbial agent is prepared by microbial fermentation of sugarcane molasses.

[0023] Further, the preparation method of the bio-organic nutrient solution includes the following steps:

[0024] (1) solid-liquid separation to remove solid residues;

[0025] (2) storing the biogas slurry after removing the solid residues and performing enzymolysis treatment;

[0026] The microbial enzyme preparation used in the enzymatic treatment process is an intracellular enzyme-containing enzyme-bacteria mixture obtained after intracellular enzymes are released from the stressed culture of Bacillus subtilis, and the preparation method of the intracellular enzyme-containing enzyme-bacteria mixture is as follows: under sterile conditions, the bacterial strain is picked from a Bacillus subtilis strain preservation slant, inoculated into a liquid culture medium, and shaken at 30 DEG C and 180 r / min for 24 h or more, when the Bacillus subtilis culture reaches an OD value of 6, stress culture is performed to make part of the bacterial bodies break and the intracellular enzymes be released; the liquid culture medium comprises 10 g of protein peptone, 5 g of yeast extract, 10 g of sodium chloride, and 1000 mL of distilled water, and is sterilized at 121 DEG C for 20 min with pH 7.0-7.2; the stress culture method comprises stopping oxygen supply, isolating oxygen, and culturing at 50 DEG C for 20 min, and then adding 5% ammonium chloride or ammonium sulfate and continuing to culture for 5 h.

[0027] In the enzymatic treatment process, the microbial enzyme preparation is added in an amount of 0.1-0.2%.

[0028] In the enzymatic treatment process, oxygen is increased, and a porous aeration head is selected as the oxygen increasing device, the number of aeration heads is configured at a ratio of 2 per square meter of the enzymatic treatment tank, the aeration head is 50 cm away from the tank bottom, an aeration pump is configured according to the volume of the enzymatic treatment tank, and the aeration amount is 0.01-0.05 vvm.

[0029] Further, the preparation method of the acidic microbial agent comprises the following steps: inoculating Bacillus amyloliquefaciens 5-25 parts by mass, Bacillus licheniformis 5-30 parts by mass, Geotrichum candidum 5-15 parts by mass, Trichoderma koningii 5-20 parts by mass, and Aspergillus niger 5-15 parts by mass into a culture medium containing 5-10% sugarcane molasses and 1-5% soybean meal solution in a ratio, stirring and mixing, and setting the initial pH value to 5.8; mechanically stirring every 1 h for 5-10 min each time, and culturing for 72 h to obtain the acidic microbial agent.

[0030] The beneficial effects of adopting the above technical solutions include that the improved formula provided by the present application is derived from an organic liquid formula obtained by microbial fermentation of organic waste generated in agricultural processing and livestock breeding, and is recycled. The preparation method of the formula is simple, and the biological organic nutrient solution and the acidic microbial agent included therein can quickly reduce the rhizosphere soil pH, improve the soil physical and chemical properties, and promote seed germination.

[0031] Further, in the process of land preparation, deep scarification / turning is performed to a depth of 40-50 cm.

[0032] The beneficial effects of adopting the above technical solutions include that the deep scarification and turning measures can break the plough pan, break the hardening, increase the soil permeability, and thus improve the efficiency of salt and alkali washing.

[0033] Further, according to the total salt content of the soil, the soil physical and chemical properties or the characteristics of the planted plants, whether to need to plant in the ridge is selected.

[0034] The beneficial effects of the above technical solution include: the ridging can break the hardened topsoil, increase the water, fertilizer and light permeability of the soil, and easily make the leached salt and alkali downwardly migrate.

[0035] Further, the salt-tolerant grass is planted in the first year, and the salt-tolerant grass includes one or more of sorghum, Sudan grass, oat grass and alfalfa; and according to the soil salt content and the soil pH value, other agricultural crop varieties are selected to be planted in the second year.

[0036] The beneficial effects of the above technical solution include: in the early stage of improvement (the first year), the salt-tolerant, high-biomass and high-protein grass varieties are selected. The growth of the grass can not only absorb the salt in the soil to reduce the soil salt content, but also activate the rhizosphere microbial activity and population number through the metabolic activity and secretion of the root system to improve the unbalanced soil microbial ecological environment. The root system and stubble of the lush grass are a high-quality source of soil organic matter. At the same time, the high-protein grass can produce considerable economic benefits.

[0037] Further, according to the soil moisture condition, a micro tank is carried out:

[0038] (1) During the seed germination period, the micro-irrigation is started immediately after sowing, and the continuous micro-irrigation is carried out for 15 days, and the total amount of each micro-irrigation is 4-5 mm; the micro-irrigation liquid is a dilute solution of acid microbial agent;

[0039] (2) After the seedling emergence, the field water holding capacity of 55% is taken as the micro-irrigation starting threshold, the micro-irrigation is started when the field water holding capacity of the plough layer soil is less than or equal to 55%, and the micro-irrigation is stopped when the field water holding capacity of the plough layer soil is higher than 55%; the micro-irrigation liquid is a dilute solution of acid microbial agent, and the total amount of each micro-irrigation is 6-7 mm; when used as a fertilizer, the micro-irrigation liquid is a dilute solution of biological organic nutrient liquid.

[0040] The beneficial effects of the above technical solution include: the micro-irrigation technology based on the soil moisture condition threshold can quickly reduce the salt content of the plough layer soil. The technology aims to quickly reduce the surface salt and alkali during the seed germination period, promotes the seed germination, quickly leaches the salt and alkali through the continuous, high-frequency and small-amount micro-irrigation technology, reduces the salt content of the surface soil, maintains the high water potential of the plant rhizosphere, and avoids the harm of physiological water deficiency of the seed under the medium and heavy salt and alkali stress. The precise micro-irrigation salt reduction technology combined with the use of acid microbial agent as the micro-irrigation liquid can reduce the salt and alkali, promote the formation of a low-salt and low-alkali microenvironment in the rhizosphere, and ensure that the plant seeds can germinate in the non-salt and alkali stress rhizosphere microenvironment. After the seedling emergence, the micro-irrigation technology based on the soil moisture condition threshold can not only meet the water and fertilizer needs of the plant, but also continue to reduce the salt and alkali to achieve the technical purpose of crop yield increase. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 Ridging diagram (only for illustration). DETAILED DESCRIPTION

[0042] The principles and features of the present application are described below in conjunction with the accompanying drawings, which are provided only for explanation of the present application and are not intended to limit the scope of the present application.

[0043] The present application provides a biological improvement method for alkaline salinized soil, comprising the following steps:

[0044] (1) Land leveling: to reduce salt and alkali accumulation in low-lying areas, for example, a laser land leveler can be used to level the land, with a deviation of ±3 cm.

[0045] (2) Soil preparation: to increase soil permeability, deep scarification / furrowing 40-50 cm, and harrowing.

[0046] (3) Apply liquid soil amendment:

[0047] Uniformly apply liquid soil amendment on each mu of alkaline salinized saline-alkali soil. The liquid soil amendment comprises biological organic nutrient solution and acidic microbial inoculant;

[0048] The biological organic nutrient solution and the acidic microbial inoculant are mixed and applied. The mass ratio of the biological organic nutrient solution to the acidic microbial inoculant can be 10:2.

[0049] (4) Mix: after applying the liquid soil amendment (3-5 days), mix the plough layer soil (25-30 cm) and the liquid soil amendment by rotary tillage, and then harrow.

[0050] (5) Ridging: to improve water and salt transport efficiency, whether to plant with ridges is selected according to the level of total salt content in the soil, the soil physical and chemical properties, or the characteristics of the planted plants. For example, sunflower, corn, and sorghum need to be planted with ridges according to the characteristics of the crops. When the total salt content of the soil is ≥0.5%, and the soil is heavy and sticky, planting with ridges is required, otherwise, no ridges can be selected.

[0051] The ridge height can be 15 cm, the ridge width can be 40-90 cm, and the ridge spacing can be 160-180 cm.

[0052] (6) Planting salt-tolerant pasture:

[0053] In the first year, salt-tolerant, salt-absorbing, high-biomass, and high-protein pasture varieties are selected, and preferred salt-tolerant pasture varieties include but are not limited to sorghum, Sudan grass, oat grass, alfalfa, etc.

[0054] When the soil salt content is reduced to 0.4% or below and the soil pH is restored to about 7.5 in the second year, other crops that are not tolerant to salt and alkali but are necessary can be selected for planting.

[0055] (7) Micro-irrigation, salt reduction, salt pressure reduction and alkali reduction:

[0056] The soil moisture content is monitored by using a field water holding capacity monitoring system.

[0057] ① Seed germination period: micro-irrigation is started immediately after sowing, and continuous micro-irrigation is performed for 15 days, with a total amount of 4-5 mm each time; the micro-irrigation liquid is an acid microbial agent diluent, and the acid microbial agent diluent is prepared by diluting the acid microbial agent and irrigation water at a mass ratio of 1:2. ② After germination, the field water holding capacity of 55% is used as the micro-irrigation starting threshold, and micro-irrigation is started when the field water holding capacity of the plough layer soil is ≤55%, and stopped when the field water holding capacity of the plough layer soil is higher than 55%; the micro-irrigation liquid is an acid microbial agent diluent, and the total amount of each micro-irrigation is 6-7 mm.

[0058] The acid microbial agent diluent is prepared by diluting the acid microbial agent and irrigation water at a mass ratio of 1:2 to 1:10.

[0059] (8) Application of biological organic nutrient liquid. According to the fertilizer requirement law of the planted crops, timely topdressing is performed. The biological organic nutrient liquid is a mixed liquid of biological organic nutrient liquid obtained by micro-aerobic microbial enzymolysis treatment of livestock and poultry manure and urine and acid microbial agent. The mass ratio of the biological organic nutrient liquid to the acid microbial agent is 10:2.

[0060] The topdressing amount is determined according to the fertilizer requirement law of the planted plants. For example, for planting hybrid sorghum, which is harvested 3 times a year, the fertilizer requirement law is that the base fertilizer is 6 kg of nitrogen, and after each harvest, 6 kg of nitrogen fertilizer is topdressed twice, a total of 30 kg of nitrogen fertilizer is needed. The nitrogen content of the biological organic nutrient liquid + acid microbial agent mixed liquid is 0.06%. Therefore, about 10 tons / acre of biological organic nutrient liquid + acid microbial agent mixed liquid is needed for each topdressing.

[0061] The biological organic nutrient liquid + acid microbial agent provided by the application can meet the nutrient requirements of most plant growth, and no inorganic fertilizer needs to be added.

[0062] Alkaline salinized soil refers to cultivated land or abandoned land soil with a pH of ≥8.5, a salt content of ≥0.5%, and an organic matter content of ≤0.5%.

[0063] The biological organic nutrient liquid provided by the present application is derived from the liquid fermentation residue of livestock and poultry manure which is insufficiently anaerobically fermented and incompletely degraded in a biogas engineering, and is obtained by micro-aerobic microbial enzymolysis treatment. The organic matter content in the biological organic nutrient liquid is ≤50 g / L, the total nutrient (N+P2O5+K2O) is ≥1 g / L, the water-soluble small molecular organic matter is ≥1 g / L, and the pH is 5.5-8.5. Specifically, the biological organic nutrient liquid is prepared by referring to the method described in the Chinese invention patent (application publication number CN 114656042A) with the liquid fermentation residue which is insufficiently anaerobically fermented and incompletely degraded as the raw material. The name of the invention patent is: a low-emission microbial enzymolysis treatment method for low-concentration biogas liquid. In the original patent application, the biological organic nutrient liquid is used to solve the problems of seedling burning and soil hardening caused by direct application of biogas liquid to the field, to reduce the transformation and emission of ammonia nitrogen, to ensure the stability of nitrogen nutrients in the biogas liquid, and to achieve the purpose of odorless, tasteless, and effective field utilization. The present application applies the organic nutrient liquid to the biological improvement of alkaline salinized soil, and achieves remarkable improvement effect in balancing nutrition, replacing chemical fertilizers, and improving crop quality.

[0064] The preparation method of the biological organic nutrient liquid comprises the following steps:

[0065] ① solid-liquid separation to remove solid residues;

[0066] ② store the biogas liquid after removing the solid residues in a suitable biogas liquid storage tank or temporary storage pool, then transport the biogas liquid to a biogas liquid enzymolysis pool, transport the microbial enzyme preparation into the enzymolysis pool by a transport pump, mix and uniformize the biogas liquid and the microbial enzyme preparation, use an oxygenation device to oxygenate the biogas liquid, and perform micro-aerobic microbial enzymolysis treatment;

[0067] ③ control the micro-aerobic microbial enzymolysis treatment time of the biogas liquid, and when the color changes from turbid green to clear red-brown, the microbial enzymolysis treatment process is completed, the biogas liquid is pumped to an enzymolysis liquid temporary storage pool, and finally the biogas liquid is treated by field application through a suitable transport pump.

[0068] In the method, the microbial enzyme preparation is an enzyme-bacteria mixture containing intracellular enzymes obtained after intracellular enzymes released by stress culture of Bacillus subtilis, and the enzyme-bacteria mixture is prepared by the following method: under sterile conditions, bacteria are picked from a Bacillus subtilis strain preservation slant and inoculated into a liquid medium, and then cultured at 30°C with a rotation speed of 180 r / min for more than 24 hours; when the Bacillus subtilis culture reaches an OD value of 6, stress culture is performed to make part of the bacterial bodies break and release intracellular enzymes; the formula of the liquid medium is as follows: 1000 mL of distilled water, 10 g of proteose peptone, 5 g of yeast extract, 10 g of sodium chloride, pH 7.0-7.2, and sterilized at 121°C for 20 minutes; further, the stress culture method is as follows: stop oxygen supply, isolate oxygen, and then culture at 50°C for 20 minutes; then, 5% ammonium chloride or ammonium sulfate is added and the culture is continued for 5 hours; the microbial enzyme preparation in step ② is added in an amount of 0.1-0.2%; further, the oxygenation device in step ② is a porous aeration head, the number of aeration heads is two per square meter, the distance between the aeration head and the bottom of the pool is 50 cm, an aeration pump is configured according to the volume of the enzyme hydrolysis pool, and the aeration amount is 0.01-0.05 vvm.

[0069] The acid microbial agent provided by the application is a composite microbial agent containing 5-25 parts by mass of Bacillus subtilis, 5-30 parts by mass of Bacillus licheniformis, 5-15 parts by mass of Geotrichum candidum, 5-20 parts by mass of Trichoderma koningii, and 5-15 parts by mass of Aspergillus niger. The acid microbial agent is prepared by the following aerobic fermentation method: the bacteria of each strain of the composite bacteria are inoculated into a culture medium containing 5-10% sugarcane molasses and 1-5% soybean meal solution in the above-mentioned proportions, respectively, and stirred and mixed uniformly, and the initial pH value is 5.8. Mechanical stirring is performed every 1 hour, and each stirring lasts for 5-10 minutes, during which the pH value gradually decreases and tends to be stable; the mixed solution produces gas, and the color gradually changes to yellow and turbid. After 72 hours of culture, the bubbles gradually disappear, and the microbial fermentation is completed, and the acid microbial agent is obtained, and the pH value is 3.9. The temperature during the preparation process is 25-30°C.

[0070] The beneficial effects of the application include:

[0071] (1) The integrated technology of the application can quickly reduce the pH of the rhizosphere soil by applying the acid microbial agent combined with precise water-saving micro-irrigation technology, so that the microenvironment of the plant rhizosphere can become a neutral pH environment suitable for seed germination and growth under the condition of high pH of the overall soil; the soil physical and chemical properties are improved, and the availability of large, medium and trace elements that cannot be utilized or are passivated due to alkaline salinization in the soil is improved; beneficial microorganisms and their metabolites such as growth-promoting hormones are provided; and biological organic nitrogen sources such as biological organic acids, amino acids, and polypeptides produced by fermentation of molasses and soybean meal can be directly utilized by microorganisms and crops.

[0072] (2) Acidic microbial agent promotes seed germination. It is found that the acidic microbial agent contains active substances that promote seed germination, and can promote the germination and rooting of pasture seeds under saline-alkali stress.

[0073] (3) Rapidly reduce the salt content of the plough layer soil by the micro-irrigation technology based on the soil moisture content threshold control. The technology aims to rapidly reduce the surface salt-alkali and promote seed germination by the continuous, high-frequency and low water consumption micro-irrigation technology to rapidly leach the salt-alkali and reduce the salt content of the surface soil, maintain the high water potential of the plant rhizosphere and avoid the physiological water deficiency of the plant seeds under the moderate to severe salt-alkali stress, which leads to the seed non-germination. The precision micro-irrigation salt reduction technology combined with the use of the acidic microbial agent as the micro-irrigation liquid improves the salt and alkali reduction efficiency, promotes the rapid formation of the low salt and alkali microenvironment in the rhizosphere and ensures the germination of the plant seeds in the non-salt-alkali stress rhizosphere microenvironment. After the emergence, the micro-irrigation technology based on the soil moisture content threshold control can meet the water and fertilizer needs of the plants and continue to reduce the salt and alkali to achieve the technical purpose of crop yield increase.

[0074] (4) Micro-aerobic microbial enzymolysis technology. The micro-aerobic microbial enzymolysis technology changes the livestock and poultry manure liquid rich in nutrients but not directly returned to the field due to incomplete fermentation into the agricultural organic nutrient liquid that can be directly returned to the field. The nutrient liquid can be used as base fertilizer and topdressing to provide the nutrient demand of plant growth. It can replace 80%-100% of the inorganic fertilizer use amount.

[0075] (5) Planting salt-alkali tolerant pasture. In the early stage of improvement (the first year), the salt-alkali tolerant, high biomass and high protein pasture varieties are selected. The growth of the pasture can absorb the salt in the soil, reduce the soil salt content, activate the rhizosphere microbial activity and population number through the metabolic activity and secretion of the root system and improve the unbalanced soil microbial ecological environment. The root system and stubble of the lush growing pasture are a kind of high-quality soil organic matter source. At the same time, the high protein pasture can also produce considerable economic benefits.

[0076] The present application can comprehensively improve the problems of the secondary salinization soil, such as soil alkalization, salt content reduction, nutrient balance, soil compaction improvement and soil microbial community proportion imbalance, by integrating the above five biological saline-alkali soil improvement technologies aiming at the main obstacle factors of the alkaline salinized soil. The improvement formula is green and organic, the improvement method is environmentally friendly, low-carbon and efficient. In the first year, the soil is improved and planted at the same time, and the fertilizer use amount is reduced by 80%-100%. After one growing season of improvement by using the technical and improvement method of the present application, the original severe alkaline salinized plough layer soil can be improved into the light to non-salinized soil, which is suitable for planting other crops that are not resistant to salt-alkali.

[0077] The following will be introduced by specific examples.

[0078] Example 1 Xinjiang strong alkaline salinization farmland soil improvement

[0079] Original soil physical and chemical indicators: soil pH 9-9.5; soil salt content 0.8-1%; organic matter content <0.5%.

[0080] (1) Level the land, reduce salt and alkali accumulation in low-lying areas. Use a laser land leveler to level the land.

[0081] (2) Soil preparation, increase soil permeability. Deep scarification / turning 50 cm; harrowing.

[0082] (3) Apply liquid soil amendment. Apply liquid soil amendment evenly on each mu of alkaline salinization saline-alkali land, the liquid soil amendment contains acid microbial agent and biological organic nutrient solution; the biological organic nutrient solution and the acid microbial agent are mixed and applied, the mass ratio of the biological organic nutrient solution to the acid microbial agent is 10:2. The biological organic nutrient solution is obtained by micro-aerobic microbial enzymolysis of livestock and poultry manure; the acid microbial agent is obtained by microbial fermentation of sugarcane molasses.

[0083] (4) Mix the liquid soil amendment. After applying the liquid soil amendment (3-5 days), spin tillage to mix the soil in the plough layer (25-30 cm) and the liquid soil amendment, and then harrow.

[0084] (5) Raising ridges. Mechanically raise ridges. As shown in Figure 1 , the ridge spacing d1 = 180 cm, d2 = d3 = d5 = d6 = 10 cm, the ridge width d4 = 50 cm, and the ridge height h = 15 cm.

[0085] (6) Planting salt-tolerant grass. The grass variety is an annual multiple-cut hybrid sorghum. Drill seeding. The seeding amount is 1.75 kg / mu. The row spacing and plant spacing are 20 cm x 10 cm. The seeding depth is 2-3 cm. Seed 2 rows per ridge (50 cm wide). Lay 1 micro-irrigation belt between the two rows.

[0086] (7) Micro-irrigation salt washing, salt pressing, and alkali reduction.

[0087] ① Immediately after seeding, start micro-irrigation on the crops using micro-irrigation. Continuous micro-irrigation for 15 days; the total amount of each micro-irrigation is 4-5 mm; the micro-irrigation liquid is a dilution liquid of acid microbial agent and irrigation water (or organic nutrient solution, used as base fertilizer) at a mass ratio of 1:2.

[0088] ② After germination, take 55% of the field water holding capacity as the micro-irrigation starting threshold, start micro-irrigation when the soil water holding capacity of the plough layer is ≤55%, and stop micro-irrigation when the soil water holding capacity of the plough layer is higher than 55%; the micro-irrigation liquid is a dilution liquid of acid microbial agent and irrigation water at a mass ratio of 1:2, and the total amount of each micro-irrigation is 6-7 mm.

[0089] (8) Topdressing biological organic nutrient liquid. The fertilizer is biological organic nutrient liquid and acid microorganism agent (mass ratio 5:1) obtained by micro-aerobic microorganism enzymolysis treatment of livestock and poultry manure. The total amount of each topdressing is 10 tons per mu. (1) When the pasture is grown to 50 cm (generally 40 days after sowing), topdressing is performed once. (2) After each harvest of pasture, topdressing is performed immediately; when the regenerative pasture is grown to 100 cm, topdressing is performed again. The biological organic nutrient liquid + acid microorganism agent of the present application can meet the nutrient needs of most plant growth, and there is no need to add inorganic fertilizers.

[0090] (9) Harvesting. The pasture variety of the present application is an annual multiple cutting hybrid sorghum. In this embodiment, three crops are harvested per year. The first crop is harvested 60-65 days after emergence, when the plant height is 1.8-2 m; the second and third crops are harvested 30-35 days after the previous crop, respectively. Each time, the stubble is left 10 cm. When the soil temperature is lower than 12℃, the hybrid sorghum stops growing.

[0091] (10) Post-harvest treatment of pasture. After the pasture is harvested, it is broken into a pit for ensiling or wrapped for ensiling.

[0092] The bio-organic nutrient liquid is derived from the liquid-state fermentation residual of livestock and poultry manure liquid that is insufficiently anaerobically fermented in a biogas project and incompletely degraded, and is obtained by micro-aerobic microbial enzymolysis treatment. The bio-organic nutrient liquid has an organic matter content of ≤50 g / L, a total nutrient (N+P2O5+K2O) content of ≥1 g / L, a water-soluble small-molecule organic matter content of ≥1 g / L, and a pH of 5.5-8.5. Specifically, the bio-organic nutrient liquid is prepared according to the method of Chinese patent CN 114656042 using the liquid-state fermentation residual that is insufficiently anaerobically fermented and incompletely degraded as a raw material: (1) solid-liquid separation to remove solid residues; (2) storing the biogas liquid after removing the solid residues in a suitable biogas liquid storage tank or temporary storage pool, then transporting the biogas liquid to a biogas liquid enzymolysis pool, transporting microbial enzyme preparations into the enzymolysis pool by a delivery pump to mix and uniformize the biogas liquid, and performing micro-aerobic microbial enzymolysis treatment by using an oxygenation device to oxygenate the biogas liquid; (3) controlling the micro-aerobic microbial enzymolysis treatment time of the biogas liquid, and when the color changes from turbid green to clear red-brown, the microbial enzymolysis treatment process is completed, the biogas liquid is pumped to an enzymolysis liquid temporary storage pool, and finally, the bio-organic nutrient liquid is treated by suitable delivery pumps and is applied to the field; the microbial enzyme preparations are enzyme and bacteria mixed liquid containing intracellular enzymes released after stress culture of Bacillus subtilis, and the enzyme and bacteria mixed liquid containing intracellular enzymes is prepared by: under sterile conditions, picking bacteria from a Bacillus subtilis strain preservation slant, inoculating the bacteria into a liquid culture medium, and oscillating and culturing at 30℃ and a rotation speed of 180 r / min for 24 h or more; when the Bacillus subtilis culture reaches an OD value of 6, stress culture is performed to make part of the bacterial bodies break and release intracellular enzymes; the liquid culture medium formula includes: 10 g of proteose peptone, 5 g of yeast extract, 10 g of sodium chloride, 1000 mL of distilled water, and pH 7.0-7.2, and sterilization at 121℃ for 20 min; further, the stress culture method is: stopping oxygen supply, isolating oxygen, culturing at 50℃ for 20 min, adding 5% ammonium chloride or ammonium sulfate, and continuing to culture for 5 h; the microbial enzyme preparation addition amount in step (2) is 0.1-0.2%; further, the oxygenation device in step (2) is a porous aeration head, the number of aeration heads is configured as two per square meter, the aeration head distance from the pool bottom is 50 cm, an aeration pump is configured according to the volume of the enzymolysis pool, and the aeration amount is 0.01-0.05 vvm.

[0093] The acid microorganism agent is a compound agent containing 20% Bacillus subtilis var. amyloliquefaciens, 25% Bacillus licheniformis, 20% Geotrichum candidum, 20% Trichoderma koningii and 15% Aspergillus niger (all by mass percentage). The acid microorganism agent is prepared by aerobic fermentation as follows: the compound bacteria of each strain are inoculated into a culture medium containing 5% sugarcane molasses and 1% soybean meal solution by mass percentage, stirred and mixed, and the initial pH value is 5.8. The culture is stirred mechanically every 1 hour for 5-10 minutes each time, during which the pH value gradually decreases and tends to be stable; the mixed solution produces gas, and the color gradually changes to yellow and turbid. After 72 hours of culture, the bubbles gradually disappear, the microorganism fermentation is completed, and the acid microorganism agent is obtained, with a pH value of 3.9.

[0094] The physicochemical indexes of the soil after using the improved formula and improved method of the application are detected, and the detection results are shown in Table 1. As can be seen from Table 1, after using the improved formula and improved method of the application, the physicochemical properties of the plough layer soil change as follows:

[0095] After the liquid soil conditioner and the soil are uniformly mixed, the pH of the plough layer soil decreases by 0.18 units, the soil salt content remains unchanged, and the organic matter of the plough layer soil increases by 0.05% (from 0.33% to 0.38%).

[0096] On the 15th day after sowing, the soil pH and salt content are significantly changed by using the precise micro-irrigation frequency, micro-irrigation amount and micro-irrigation liquid of the application. The pH decreases from 9.08 of the original soil to 8.05, with a decrease of 11.3%; the soil salt content decreases from 0.89% of the original soil to 0.51%, with a decrease of 42.7%. The soil salinity decreases from severe to moderate. The organic matter content increases from 0.38% of the original soil to 0.39% at the same period.

[0097] After the production is completed, the pH decreases from 9.08 of the original soil to 7.08, with a decrease of 22%; the salt content decreases from 0.89% of the original soil to 0.41%, with a decrease of 53.9%; and the soil organic matter content increases by 0.08%. At the end of the production cycle, the degree of salinization of the actual plough layer (0-20 cm) soil has been improved from severe (0.89%) of the original to mild (0.41%), and the soil pH has been improved from strong alkaline (9.08) to slightly neutral (7.08).

[0098] Table 1 Change of salt content and organic matter of plough layer soil

[0099]

[0100] Although the hybrid sorghum variety selected in Example 1 is a relatively salt-tolerant forage grass, it cannot germinate and grow in the original saline-alkali soil of the present application. After using the liquid soil conditioner and soil improvement technology of the present application, a technical effect of 95% emergence rate, 6 tons per mu yield and 13.4% protein content of hybrid sorghum is achieved (Table 2).

[0101] Table 2 Forage yield and quality

[0102]

[0103]

[0104] As can be seen from the data in Tables 1 and 2, within 15 days after sowing, the salt-alkali content of the plough layer soil is reduced from the original pH 9.01 and salt content 0.89% to pH 8.05 and salt content 0.51%, and the degree of salinization is changed from severe alkaline saline soil to medium-light saline soil. After a production period, the plough layer soil is improved from severe salinization (pH 9.01, salt content 0.89%) to light salinization (pH 7.08, salt content 0.41%) (Table 1), and at the same time of soil improvement, a technical effect of 95% emergence rate, 6 tons per mu yield and 13.4% protein content of hybrid sorghum and 100% reduction of fertilizer usage is achieved (Table 2). It is shown that the biological improvement formula and improvement technology of the present application for severe alkaline salinized soil is effective.

[0105] In summary, the liquid soil conditioner and soil improvement technology of the present application can quickly reduce the pH and salt content of the soil.

[0106] To further demonstrate the beneficial effects of the method provided by the present application, Experiments 1 to 5 are provided.

[0107] Experiment 1 Influence of different saline-alkali land improvement measures on the efficiency of reducing alkalinity and salt

[0108] The present application uses land leveling, deep scarification and ridging measures for saline-alkali land improvement, which is the main component of achieving the technical effect of the present application. In order to illustrate the importance of these measures, in Experiment 1, the salt-reducing and alkalinity-reducing efficiency of Example 1 is compared with those of Comparative Examples 1 to 3.

[0109] Comparative Example 1: uneven land, other steps same as Example 1;

[0110] Comparative Example 2: no deep scarification, other steps same as Example 1;

[0111] Comparative Example 3: no ridging, other steps same as Example 1.

[0112] The experimental results of the influence of different improvement measures on the pH and total salt content of the plough layer soil are shown in Table 3.

[0113] Compared with Example 1, Comparative Example 1 does not adopt the land leveling measure. The experiment proves that uneven land can cause uneven distribution of water and fertilizer, and the low-lying place can cause water and fertilizer accumulation, and the salinity and alkalinity increase significantly, and the difficulty of governance and improvement increases. In Comparative Example 1, the soil of the low-lying land accounting for 15%-20% of the total area increases the difficulty of governance and improvement due to the increase of salinity and alkalinity caused by water and fertilizer accumulation, and at the end of production, the pH reduction (1.01) is 0.99 pH units less than that (2.00) of Example 1; the reduction of total salt (0.22%) is 0.26% less than that (0.48%) of Example 1.

[0114] Comparative Example 2 does not adopt the deep scarification and deep ploughing measure. The deep scarification and deep ploughing measure can break the plough pan, break the hardening, increase the soil permeability, and thus improve the efficiency of salt leaching and alkali compression. Compared with Example 1, at the end of the production cycle, the salt reduction (0.21%) and alkali reduction (0.63) of Comparative Example 2 are 0.27% and 1.37 pH units lower than those (0.48%) and (2.00) of Example 1, respectively.

[0115] Comparative Example 3 does not adopt the ridging measure. The ridging can break the hardening of the surface soil, increase the water permeability, air permeability, fertilizer permeability and light permeability of the soil, and easily make the leached salt and alkali migrate downward. Compared with Example 1, at the end of the production cycle, the salt reduction (0.18%) and alkali reduction (0.53) of Comparative Example 3 are 0.30% and 1.47 pH units lower than those (0.48%) and (2.00) of Example 1, respectively.

[0116] Table 3 Influence of different improvement measures on pH and total salt content of plough layer soil

[0117]

[0118]

[0119] From the above experimental results, it can be seen that land leveling, deep scarification and deep ploughing and ridging are effective measures for improving alkaline and saline soil.

[0120] Experiment 2 Influence of different soil improvement formulations or micro-irrigation methods on salt leaching and alkali reduction effect and forage quality

[0121] In this experiment, the salt leaching and alkali reduction effects of Example 1 and Comparative Example 4 or Comparative Example 5 are compared respectively.

[0122] Comparative Example 4: solid organic fertilizer + mineral humic acid alkali compression agent is used as base fertilizer instead of liquid soil improvement agent (liquid biological organic nutrient solution + acid microorganism agent) in Example 1, and the others are the same as Example 1.

[0123] The solid organic fertilizer is prepared by a four-stage fermentation method using cow dung and enzyme-bacteria complex fermentation agent (Chinese invention patent CN 113582736 B). Specifically, different high-lignin waste is crushed to a particle size of <5 cm, and then mixed with cow dung in a barrel mixer for 10-15 minutes, with the mass ratio of high-lignin waste to cow dung being 1:7. During the mixing process, 5‰ of the enzyme-bacteria complex fermentation agent is added, which contains lignin-degrading complex bacterial agent and crude intracellular enzyme extract of Bacillus licheniformis. After mixing, the moisture content of the agricultural and forestry waste material is adjusted to 55%, the carbon-nitrogen ratio is adjusted to 25:1, and the bulk density is adjusted to 500 kg / m 3 . The fermentation raw material is obtained. The fermentation raw material is placed in a fermentation container, and a high-pressure aeration pipe connected to an air pump is installed at the bottom of the fermentation container. The air supply is controlled by an air flow meter.

[0124] The raw material fermentation step: the fermentation raw material is not turned over and transported during the fermentation process, and the fermentation period is 25-35 days. The fermentation is divided into four stages, and the temperature and high-pressure air supply are controlled for each of the four fermentation stages.

[0125] A. Temperature rising and high oxygen stage: adjust the temperature of the raw material to rapidly rise above 65°C, the air supply of the high-pressure aeration pipe is 0.42-0.47 m 3 / h / m 3, and the fermentation time is 4-6 days.

[0126] B. High temperature and low oxygen stage: control the temperature of the compost raw material to be maintained at 70-80°C, adjust the air supply to be 0.20-0.25 m 3 / h / m 3 , and the fermentation time is 6-9 days.

[0127] C. Temperature decreasing and low oxygen stage: control the temperature of the compost raw material to gradually decrease to below 40°C, adjust the air supply to be 0.05-0.15 m 3 / h / m 3 , and the fermentation time is 7-10 days.

[0128] D. Normal temperature and standing stage: control the temperature of the compost raw material to decrease to normal temperature, stop aeration, and stand for 7-10 days to complete the fermentation.

[0129] The mineral humic acid alkali agent is the YiTuLong alkali agent produced by Xinjiang Ruifengde.

[0130] Comparative Example 5: Use conventional drip irrigation instead of the optimized micro-irrigation method of Example 1, with the drip irrigation frequency and amount being 6-7 mm every 3 days. The other conditions are the same as those of Example 1.

[0131] The experimental results of the effects of different improvement formulations or micro-irrigation or drip irrigation methods on salt washing and alkali reduction and pasture yield are shown in Table 4.

[0132] The comparative example 4 uses solid organic fertilizer + mineral humic acid press alkali agent as base fertilizer formula, and its alkali reduction effect reduces pH by 1.07 at the end of the experiment, and the soil pH is still alkaline (pH 8.01), while the alkali reduction effect of example 1 after applying liquid organic nutrient solution + acidic microbial agent is significant, and the pH is reduced by 2 units at the end of the experiment, and the soil is neutral (pH 7.08). The salt reduction effect of comparative example 4 and example 1 is comparable, and it is possible that both use the same precision salt washing micro-irrigation mode, but the seedling emergence rate (68%), tillering number (3) and yield per mu (4.5 tons) of the pasture of comparative example 4 are all significantly lower than the seedling emergence rate (95%), tillering number (5) and yield per mu (6 tons) of example 1.

[0133] The comparative example 5 uses conventional drip irrigation, drip irrigation frequency and drip irrigation amount, i.e. drip irrigation every 3 days, and the drip irrigation amount is 6-7 mm each time. The results show that the total salt content of comparative example 5 is only reduced by 0.08% at the end of production, and the soil total salt content remains at a high level of 0.81%; the pH is reduced by 0.07 units, and the soil pH remains at a high level of 9.01. The salt reduction and alkali reduction effects of example 1 are significantly higher than those of comparative example 5. At the end of the experiment, the soil pH of example 1 has been reduced to neutral (pH 7.08), and the soil salt content has been reduced to light (0.41%). At the same time, the seedling emergence rate (70%), tillering number (3) and yield per mu (4.6 tons) of the pasture of comparative example 5 are all lower than the seedling emergence rate (95%), tillering number (5) and yield per mu (6 tons) of example 1. Obviously, the acid liquid modification formula of the present application combined with the precision micro-irrigation mode ensures the technical effects of rapid salt reduction and alkali reduction, high seedling emergence rate and high yield of the pasture of example 1.

[0134] Table 4 Effect of different modification formulas or micro-irrigation modes on salt washing and alkali reduction and pasture yield

[0135]

[0136] Table 3 Effect of different modification formulas or micro-irrigation modes on salt washing and alkali reduction and pasture yield

[0137] In order to obtain the stable acidic microbial agent in example 1, the effects of different fermentation times on the pH, color and odor of the acidic microbial agent were compared, and the optimal fermentation time was obtained.

[0138] As shown in Table 5, when the room temperature is fermented to 72h, the color of the fermentation liquid changes from dark brown to light yellow brown, the taste changes from thick sugar taste to sour taste, the gas production stops, the pH stabilizes at 3.88, the fermentation is completed, and the acidic microbial agent of the present application is obtained.

[0139] Table 5 Effect of different fermentation times on the pH of the acidic microbial agent

[0140] In order to obtain the stable acidic microbial agent in example 1, the effects of different fermentation times on the pH, color and odor of the acidic microbial agent were compared, and the optimal fermentation time was obtained.

[0141]

[0142] Experiment 4: Acidic microbial agent promotes seed germination test

[0143] The acidic microbial agent of the present application not only neutralizes the alkalinity of saline-alkali soil, but also promotes seed germination.

[0144] In this experiment, treatments 1 to 8 were set up. Different solutions were sprayed on the original alkaline saline-alkali soil of Example 1, and seed germination tests were carried out on the soil. After the test, the soil pH and total salt content were detected, and the seed germination rate was calculated.

[0145] Treatment 1: non-saline-alkali distilled water control group;

[0146] Treatment 2: spray the original alkaline saline-alkali soil of Example 1 with acidic microbial agent (pH 3.88);

[0147] Treatment 3: spray the original alkaline saline-alkali soil of Example 1 with organic nutrient solution;

[0148] Treatment 4: spray the original alkaline saline-alkali soil of Example 1 with mixed solution (organic nutrient solution and acidic microbial agent mixed in a mass ratio of 10:1);

[0149] Treatment 5: spray the original alkaline saline-alkali soil of Example 1 with mixed solution (organic nutrient solution and acidic microbial agent mixed in a mass ratio of 10:2);

[0150] Treatment 6: spray the original alkaline saline-alkali soil of Example 1 with mixed solution (organic nutrient solution and acidic microbial agent mixed in a mass ratio of 10:3);

[0151] Treatment 7: spray the original alkaline saline-alkali soil of Example 1 with mixed solution (organic nutrient solution and high-temperature boiled acidic microbial agent mixed in a mass ratio of 10:2);

[0152] Treatment 8: spray the original alkaline saline-alkali soil of Example 1 with distilled water.

[0153] The experimental results are shown in Table 6. Treatment 1 served as a control; the germination rate of seeds in non-saline distilled water was ≥95%, indicating normal seed germination. Treatment 2 showed a germination rate ≤20% in acidic microbial inoculant (pH 3.88), indicating that the acidic microbial inoculant (pH 3.88) inhibited seed germination. Treatment 3 showed a germination rate ≥94% in organic nutrient solution, indicating that the organic nutrient solution did not inhibit seed germination. Treatment 4, using a 10:1 mixture of organic nutrient solution and acidic microbial inoculant sprayed on the soil of Example 1, increased the seed germination rate to 40%, higher than the results of Treatment 8 (seed germination rate ≤20%), indicating that the 10:1 mixture of organic nutrient solution and acidic microbial inoculant had a certain promoting effect on seed germination under high salinity conditions. Treatment 5, using a 10:2 mixture of organic nutrient solution and acidic microbial agent sprayed on the soil of Example 1, resulted in a seed germination rate of 60%, indicating that this 10:2 mixture had a good promoting effect on seed germination under high salt (0.86%) conditions. Treatment 6, using a 10:3 mixture of organic nutrient solution and acidic microbial agent sprayed on the soil of Example 1, resulted in a seed germination rate that decreased to 55%. This indicates that the 10:2 mixture in Treatment 5 had the best effect on promoting seed germination. Treatment 7, using a 10:2 mixture of organic nutrient solution and acidic microbial agent that had been boiled at high temperature, resulted in a seed germination rate of 35% in Treatment 7. Compared with Treatment 5, Treatment 7 had the same mixing ratio, soil pH, and soil salt content; the only difference was that the acidic microbial agent in Treatment 7 had been treated at high temperature. The seed germination rate in Treatment 7 was only 35%, lower than that in Treatment 5 (60%). This indicates that acidic microbial agents contain heat-sensitive active substances that promote seed germination. These substances are deactivated after heating, ultimately leading to a decrease in seed germination rate.

[0154] The results showed that strong acid (pH 3.88), strong alkali (pH 9.01) and / or high salt (0.86%) inhibited seed germination; the microbial agent of the present invention contains heat-sensitive active substances that promote seed germination and can promote seed germination and growth under salt and alkali stress; the promoting effect of the microbial agent on seed germination is more significant after dilution at a ratio of 10:2.

[0155] Table 6 compares the effects of different treatments of acidic microbial agents on seed germination.

[0156]

[0157]

[0158] Notes: 1. Seed germination substrate: treated under the conditions of treatments 1 to 8 respectively. 2. Microbial agent: the acidic microbial agent of Example 1, pH 3.88. 3. Organic nutrient solution: the organic nutrient solution of Example 1, pH 6.6.

[0159] Experiment 5 Effectiveness of salt and alkali-intolerant pasture grass

[0160] The steps of this example, except for the selection of salt and alkali-intolerant corn silage varieties, are exactly the same as those of Example 1, including the soil and implementation steps.

[0161] The original soil physical and chemical indicators are: soil pH 9-9.5; soil salt content 0.8-1%; organic matter content <0.5%.

[0162] (1) Level the land to reduce salt and alkali accumulation in low-lying areas. Use a laser land leveler to level the land.

[0163] (2) Increase soil permeability by deep scarification / turning 50 cm; harrow.

[0164] (3) Apply liquid soil conditioner. Apply liquid soil conditioner evenly over each mu of alkaline and saline-alkali land. The liquid soil conditioner contains:

[0165] 10 tons of bio-organic nutrient solution obtained by micro-aerobic microbial enzymolysis of livestock and poultry manure;

[0166] 2 tons of acidic microbial agent obtained by microbial fermentation of sugarcane molasses.

[0167] The bio-organic nutrient solution and acidic microbial agent can be mixed and applied sequentially or separately.

[0168] (4) Mix the liquid soil conditioner. After applying the liquid soil conditioner (3-5 days), spin to mix the soil layer (25-30 cm) and the liquid soil conditioner, and then harrow.

[0169] (5) Raising ridges. Mechanically raise ridges. Ridges are 15 cm high, 50 cm wide, and 180 cm apart.

[0170] (6) Planting salt and alkali-intolerant pasture grass. The pasture grass variety is annual corn silage. Drill. The planting density per mu is 6500-7000 plants. The row spacing is 60 cm x 18 cm. The seeding depth is 4-5 cm. Plant one row per ridge. Lay one micro-irrigation belt.

[0171] (7) Micro-irrigation to wash salt and press salt to reduce alkali. ① Start micro-irrigation immediately after planting. Continuous micro-irrigation for 15 days; the total amount of each micro-irrigation is 4-5 mm; the micro-irrigation liquid is a dilution of acidic microbial agent and irrigation water at a mass ratio of 1:2. ② After germination, use 55% of the field water holding capacity as the micro-irrigation starting threshold. When the soil water holding capacity of the plough layer is ≤55%, start micro-irrigation; when the soil water holding capacity of the plough layer is higher than 55%, stop micro-irrigation; the micro-irrigation liquid is a dilution of acidic microbial agent and irrigation water at a mass ratio of 1:2, and the total amount of each micro-irrigation is 6-7 mm.

[0172] (8) Topdressing with bio-organic nutrient solution. The fertilizer is the bio-organic nutrient solution obtained by microaerobic microbial enzymatic hydrolysis of livestock and poultry manure according to the present invention, and acidic microbial inoculants. The total amount of fertilizer applied each time is 10 tons / mu. Topdressing is applied once when the corn reaches the small trumpet stage (8 leaves unfolded) and again 8-10 days before tasseling. The bio-organic nutrient solution + acidic microbial inoculants of the present invention can meet the nutritional needs of most plant growth, and there is no need to add inorganic fertilizers.

[0173] (9) Harvesting.

[0174] (10) Post-harvest processing of forage. After the whole corn plant is harvested, it is crushed and put into a cellar for silage or wrapped for silage.

[0175] The experimental results of the effects of soil improvement on the emergence rate, yield, and protein content of silage corn are shown in Table 7. Silage corn cannot germinate and grow in the original strongly alkaline and saline soil. Compared with the salt-tolerant hybrid sorghum of Example 1, silage corn is not tolerant of salt and alkali, but can grow in slightly saline soil (salt content ≤0.4%, pH ≤8.5). After using the liquid soil conditioner and improvement measures provided by this invention, silage corn can germinate and grow in the improved soil, with a seed emergence rate of 67%, a total plant biomass yield (fresh yield per mu) of 3 tons, and a protein content (dry basis) of 6.5%, showing significant effects. It can be seen that after soil improvement using the method provided by this invention, crops that are originally unsuitable for growing in strongly alkaline and saline soil can grow in the improved soil, achieving the goal of increasing yield and income, further demonstrating that the technology of this invention is rapid and effective in improving strongly alkaline and saline soil.

[0176] Table 7. Effects of soil improvement on emergence rate, yield, and protein content of silage maize.

[0177]

[0178] In summary, the integrated technology provided by this invention can rapidly improve the physicochemical properties of alkaline saline soils, reducing salinity and alkali. In the early stages of seed germination, it rapidly reduces the pH and salt content of the root zone soil, ensuring seed germination and emergence. At the end of the growth cycle (6 months), the integrated technology can improve severely alkaline saline soils into slightly saline soils suitable for most non-salt-tolerant crops. Simultaneously, the emergence rate, yield, and quality of selected salt-tolerant hybrid sorghum are significantly improved. Notably, while improving severely alkaline saline soils, selected non-salt-tolerant silage corn can also germinate and grow, yielding 3 tons of whole plants with 6.5% protein content per acre. The improved formula of this invention is organic and ecological, meeting the nutritional needs of hybrid sorghum and silage corn, and 100% replacing the use of inorganic fertilizers. It is innovative.

[0179] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A biological improvement method for alkaline salinized soil, characterized in that, Includes items (1) to (7); (1) Flat ground; (2) Land preparation; (3) Apply liquid soil conditioner, which includes biological organic nutrient solution and acidic microbial agent; the mass ratio of biological organic nutrient solution to acidic microbial agent is 10:2; the biological organic nutrient solution is prepared by microaerobic microbial enzymatic hydrolysis of livestock and poultry manure. The preparation method of biological organic nutrient solution includes the following steps: Solid-liquid separation to remove solid residue; The biogas slurry after solids removal is stored and then subjected to enzymatic hydrolysis. The microbial enzyme preparation used in the enzymatic hydrolysis process is a mixture of enzymes and bacteria containing intracellular enzymes, obtained by stress-cultured Bacillus subtilis to release intracellular enzymes. The preparation method of the enzyme-bacterial mixture containing intracellular enzymes includes: under aseptic conditions, picking bacteria from the Bacillus subtilis strain preservation slant, inoculating it into liquid culture medium, and incubating it at 30°C with shaking at 180 r / min for more than 24 hours. When the Bacillus subtilis reaches an OD value of 6, it is subjected to stress culture to cause partial cell rupture and release of intracellular enzymes. The liquid culture medium formula includes: per 1000 mL of distilled water, 1 part peptone... 0g, yeast extract 5g, sodium chloride 10g, pH 7.0-7.2, sterilized at 121℃ for 20min; the stress culture method includes: stopping oxygen supply, isolating oxygen, culturing at 50℃ for 20min, adding 5% ammonium chloride or ammonium sulfate, and continuing culture for 5h; during the enzymatic hydrolysis process, the amount of microbial enzyme preparation added is 0.1-0.2%; during the enzymatic hydrolysis process, oxygen is added, and the oxygenation device is a porous aeration head, with the number of aeration heads configured at a ratio of 2 per square meter of enzymatic hydrolysis tank, the aeration head is 50cm from the bottom of the tank, and the aeration pump is configured according to the volume of the enzymatic hydrolysis tank, with an aeration rate of 0.01-0.05vvm; Acidic microbial inoculants are prepared by microbial fermentation of sugarcane molasses; The preparation method of acidic microbial inoculant includes the following steps: Inoculate each of the following microorganisms into a culture medium containing 5-10% sugarcane molasses and 1-5% soybean meal solution according to the following ratio: 5-25 parts by weight of Bacillus subtilis, 5-30 parts by weight of Bacillus licheniformis, 5-15 parts by weight of Geotrichum candelilla, 5-20 parts by weight of Trichoderma koningii, and 5-15 parts by weight of Aspergillus niger. Stir and mix well, with an initial pH of 5.

8. Mechanically stir once every hour for 5-10 minutes each time, and incubate for 72 hours to obtain an acidic microbial inoculant with a pH of 3.

9. (4) Ridging; (5) Plant salt-tolerant forage grasses; (6) Micro-irrigation; (7) Apply biological organic nutrient solution and acidic microbial agents as top dressing.

2. The biological improvement method for alkaline saline soil according to claim 1, characterized in that, During land preparation, deep loosening / turning should be carried out to a depth of 40-50cm.

3. A biological improvement method for alkaline saline soil according to claim 1 or 2, characterized in that, Whether or not ridge planting is necessary depends on the total salt content of the soil, the soil's physical and chemical properties, or the characteristics of the plant.

4. A biological improvement method for alkaline saline soil according to claim 1 or 2, characterized in that, In the first year, salt-tolerant forage grasses are planted, including one or more of sorghum, Sudan grass, oat grass, and alfalfa; in the second year, other agricultural and economic crops are selected for planting based on soil salinity and pH.

5. A biological improvement method for alkaline saline soil according to claim 1 or 2, characterized in that, Micro-irrigation should be carried out based on soil moisture conditions: (1) During the seed germination period, micro-irrigation should begin immediately after sowing and continue for 15 days, with a total amount of 4-5 mm each time; the micro-irrigation solution is a diluted solution of acidic microbial inoculant; (2) After emergence, the field water holding capacity is 55% as the threshold for micro-irrigation. Micro-irrigation is started when the field water holding capacity of the topsoil is ≤55% and stopped when the field water holding capacity of the topsoil is higher than 55%. The micro-irrigation solution is a diluted solution of acidic microbial agent, and the total amount of micro-irrigation each time is 6-7mm.

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