Modifier for soda saline-alkali soil and preparation method thereof

Abstract

The invention belongs to the technical field of soda saline-alkali soil improvement, and particularly relates to a modifier for soda saline-alkali soil and a preparation method of the modifier. The invention provides a soda saline-alkali soil improver which comprises the following components: humic acid, charcoal, polyglutamic acid, dilute nitric acid, phosphogypsum, a microbial agent and molasses. The modifier can play roles in improving the soil structure and physicochemical properties of the soda saline-alkali soil, enhancing the adaptability and tolerance of crops to adverse environments, improving the productivity of the soda saline-alkali soil and the like; the organic compound fertilizer is prepared from the modifier, urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate and composted animal dung, so that the salt content and alkali content of the soda saline-alkali soil can be reduced, the adaptability and tolerance of crops to the unfavorable environment of the soda saline-alkali soil can be improved, and the growth and development of the crops and the yield improvement are promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of soda saline-alkali land improvement, and in particular relates to a soda saline-alkali land improver and a preparation method thereof. Background Art

[0002] Soda saline-alkali land refers to land with excessive accumulation of saline-alkali components on the surface, which contains a large amount of sodium carbonate and sodium bicarbonate. The large accumulation of these salts in the soil will lead to high soil pH, damage to soil structure, reduced air permeability and water permeability, and reduced effectiveness of nutrients. Soil with high salt and alkalinity content makes it difficult for plants to absorb inorganic nutrients and water, which is not conducive to the growth and development of organisms, resulting in waste of soil resources and reduced crop yields, and thus causing direct or indirect economic losses.

[0003] At present, there are many improvement measures for the treatment of saline-alkali land, including physical improvement: leveling the land, deep plowing and drying, adding soil to suppress alkali, etc.; water conservancy project improvement: including drainage and irrigation matching, storing fresh water to suppress salt, irrigation to wash salt, etc.; biological improvement: planting salt-tolerant plants, applying microbial fertilizers, etc.; chemical improvement: applying gypsum, superphosphate, humic acid, silicon-calcium minerals, etc.; comprehensive treatment measures: including the comprehensive use of physical, chemical, and microbial methods, but they have the disadvantages of high cost, slow effect, and difficulty in large-scale promotion and application.

[0004] Therefore, there is an urgent need for a method for efficiently improving soda saline-alkali land. Summary of the invention

[0005] The purpose of the present invention is to provide a soda saline-alkali land modifier, which can effectively improve the soil structure and physical and chemical properties of the soda saline-alkali land, enhance the adaptability and tolerance of crops to adverse environments, and improve the productivity of the soda saline-alkali land.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides a soda saline-alkali land improver, comprising the following components in parts by mass: 20-30 parts of humic acid, 15-25 parts of biochar, 4-8 parts of polyglutamic acid, 1-4 parts of dilute nitric acid, 8-16 parts of phosphogypsum, 5-10 parts of microbial agent and 0.8-2.4 parts of molasses.

[0008] Preferably, the humic acid includes one or more of lignite, weathered coal and peat.

[0009] Preferably, the biochar is obtained by calcining organic matter; the organic matter includes straw and / or livestock manure.

[0010] Preferably, the microbial agent includes one or more of Bacillus subtilis, Bacillus licheniformis, Trichoderma harzianum and Bacillus firmus.

[0011] The present invention also provides a method for preparing the improver, comprising the following steps:

[0012] (1) mixing humic acid and dilute nitric acid at 80-100° C. to obtain activated humic acid;

[0013] (2) mixing the biochar, molasses, and microbial agent, and drying to obtain a mixture;

[0014] (3) The mixture, activated humic acid, phosphogypsum and polyglutamic acid are mixed at 45-55° C. to obtain an improver.

[0015] Preferably, in step (1), the mixing time is 20 to 40 minutes.

[0016] Preferably, in step (2), the drying is low-temperature drying; the drying temperature is 10 to 30° C., and the drying time is 4 to 6 hours.

[0017] The present invention also provides an organic compound fertilizer for improving soda saline-alkali land, comprising the following components: urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate, decomposed poultry and livestock manure and an improver;

[0018] The weight ratio of the urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate, decomposed poultry and livestock manure and the improver is 25-35:18-26:30-40:1-6:30-40:8-14.

[0019] The improver is the improver described.

[0020] As a preference, the method comprises the following steps:

[0021] The improver, urea, diammonium phosphate, potassium sulfate, polyferric sulfate and decomposed poultry and livestock manure are mixed to obtain an organic compound fertilizer.

[0022] The present invention also provides a method for improving soda saline-alkali land, comprising the following steps:

[0023] 1) spreading the organic compound fertilizer in the soda saline-alkali land, ploughing to a depth of 20 to 30 cm, and balancing for 2 to 4 days to obtain the initially treated soda saline-alkali land;

[0024] 2) Irrigate the initially treated soda saline-alkali land and balance it for 5 to 10 days to obtain improved saline-alkali land.

[0025] Beneficial effects of the present invention:

[0026] The present invention prepares a soda saline-alkali land improver by mixing humic acid, biochar, polyglutamic acid, dilute nitric acid, phosphogypsum, microbial agent and molasses, wherein the humic acid can reduce the pH and exchangeable sodium ion content of the soda saline-alkali land through adsorption, exchange and acid-base neutralization, thereby improving the soil physical and chemical properties, and after activating the humic acid with dilute nitric acid, the cation exchange capacity of the humic acid can be improved, and the ability of the humic acid to absorb and store potassium ions can be improved, thereby improving the utilization rate of potassium fertilizer; however, the absorption capacity of the humic acid to phosphorus ions can be reduced, resulting in the loss of phosphorus fertilizer; mixing the activated humic acid with polyglutamic acid can reduce the loss of phosphorus fertilizer, and the polyglutamic acid can help crops in the soda saline-alkali land maintain normal ion balance, reduce the crop transpiration rate, and improve the immunity of the crops, thereby enhancing the crops' resistance to salt damage, drought and pests and diseases. Resistance; Biochar can improve the soil structure of soda saline-alkali land, enhance the nutrient content and water retention capacity, and effectively control the migration and accumulation of salt; Phosphogypsum is rich in nutrients such as phosphorus and potassium, which can provide certain nutrient support for crops while improving the soil, promote crop growth and development, and improve the productivity of soda saline-alkali land; Microbial agents mainly based on Bacillus subtilis, Bacillus licheniformis, Trichoderma harzianum and Bacillus firmus release specific active substances and metabolites, participate in chemical reactions in the soil of soda saline-alkali land, convert soluble salts into insoluble salts, thereby reducing soil pH and helping to adjust the soil microenvironment; Molasses can not only provide nutrients for microbial agents, but also improve the soil structure of soda saline-alkali land and enhance water retention performance, while improving the absorption and utilization efficiency of nutrients by crops and promoting crop growth and development. The present invention combines the above components, and the prepared improver can play the role of improving the soil structure and physical and chemical properties of soda saline-alkali land, enhancing the adaptability and tolerance of crops to adverse environments, and improving the productivity of soda saline-alkali land;

[0027] The present invention prepares an organic compound fertilizer from improver, urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate and decomposed poultry and livestock manure, which can not only reduce the salt content and alkali content of soda saline-alkali land, but also supplement and balance the content of mineral elements in the soda saline-alkali land, increase the organic components and humus content in the soil, thereby improving the adaptability and tolerance of crops to the adverse environment of soda saline-alkali land, promoting crop growth and development and increasing yield. DETAILED DESCRIPTION

[0028] The present invention provides a soda saline-alkali land improver, comprising the following components in parts by weight:

[0029] Humic acid 20-30 parts, preferably 23-27 parts, more preferably 25 parts;

[0030] 15 to 25 parts of biochar, preferably 18 to 22 parts, more preferably 20 parts;

[0031] 4 to 8 parts of polyglutamic acid, preferably 5 to 7 parts, more preferably 6 parts;

[0032] 1 to 4 parts of dilute nitric acid, preferably 2 to 3 parts, more preferably 2.5 parts;

[0033] 8 to 16 parts of phosphogypsum, preferably 10 to 14 parts, more preferably 12 parts;

[0034] 5 to 10 parts of microbial agent, preferably 7 to 8 parts, more preferably 7.5 parts;

[0035] The amount of molasses is 0.8 to 2.4 parts, preferably 1.2 to 2.0 parts, and more preferably 1.6 parts.

[0036] In the present invention, the humic acid comprises one or more of lignite, weathered coal and peat, preferably lignite and / or peat, more preferably lignite and peat;

[0037] The mass ratio of peat to lignite is 1:1 to 3, more preferably 1:2;

[0038] If the humic acid is lignite, weathered coal and peat, the mass ratio of lignite, weathered coal and peat is 1-3:1-3:1, preferably 2:2:1.

[0039] In the present invention, the biochar is obtained by calcining organic matter; the organic matter includes straw and / or livestock manure, preferably straw and livestock manure;

[0040] The mass ratio of the straw to livestock manure is 1:0.5-1.5, and more preferably 1:1.

[0041] In the present invention, the calcination temperature is 300-400°C, preferably 330-370°C, and more preferably 350°C;

[0042] The calcination time is preferably 2 to 4 hours, more preferably 2.5 to 3.5 hours, and more preferably 3 hours;

[0043] The straw is corn straw and / or wheat straw, preferably corn straw and wheat straw;

[0044] The mass ratio of the corn straw to the wheat straw is 1:0.5-1.5, preferably 1:1;

[0045] The livestock excrement is cow dung and / or sheep dung, preferably cow dung and sheep dung;

[0046] The mass ratio of the cow dung to the sheep dung is 1:2-4, and more preferably 1:3.

[0047] In the present invention, the microbial agent includes one or more of Bacillus subtilis, Bacillus licheniformis, Trichoderma harzianum and Bacillus firmus, preferably Bacillus subtilis, Bacillus licheniformis, Trichoderma harzianum and Bacillus firmus;

[0048] The mass ratio of the Bacillus subtilis, Bacillus licheniformis, Trichoderma harzianum and Bacillus firmus is 1:2-6:1-3:0.2-0.8, preferably 1:3-5:1.3-2.7:0.4-0.6, and more preferably 1:4:2:0.5.

[0049] In the present invention, the Bacillus subtilis is Bacillus subtilis strain LD1, purchased from the General Microbiological Center of China Microbiological Culture Collection Administration, with a collection number of CGMCC No. 14680;

[0050] The initial concentration of Bacillus subtilis was 1×10 7 ~10 9 CFU / g, preferably 1×10 8 CFU / g;

[0051] The Bacillus licheniformis is Bacillus licheniformis BL-09, purchased from the General Microbiological Center of China Microbiological Culture Collection Administration, with a collection number of CGMCC No. 5686;

[0052] The initial concentration of Bacillus licheniformis was 1×10 6 ~9×10 7 CFU / g, preferably 4.5×10 7 CFU / g;

[0053] The Trichoderma harzianum is Trichoderma harzianum HN-2, purchased from China Center for Type Culture Collection, with a collection number of CCTCC No.M2010119;

[0054] The initial concentration of Trichoderma harzianum is 1 to 5×10 10 CFU / g, preferably 2.5×10 10 CFU / g;

[0055] The Bacillus firmus is Bacillus firmus QR-2, purchased from the General Microbiological Center of China National Microbiological Culture Collection Committee, with a collection number of CGMCC No. 18408;

[0056] The initial concentration of Bacillus firmus is 3 to 9×107 CFU / g, preferably 6×10 7 CFU / g.

[0057] In the present invention, the initial concentration of the dilute nitric acid is 10-20 wt %, preferably 13-17 wt %, and more preferably 15 wt %.

[0058] The present invention also provides a method for preparing the improver, comprising the following steps:

[0059] (1) mixing humic acid and dilute nitric acid at 80-100° C. to obtain activated humic acid;

[0060] (2) mixing the biochar, molasses, and microbial agent, and drying to obtain a mixture;

[0061] (3) The mixture, activated humic acid, phosphogypsum and polyglutamic acid are mixed at 45-55° C. to obtain an improver.

[0062] In the present invention, in step (1), the humic acid needs to be crushed to 50-60 mesh, preferably 53-57 mesh, and more preferably 55 mesh before mixing the humic acid and dilute nitric acid;

[0063] The mixing time is 20 to 40 minutes, preferably 25 to 35 minutes, and more preferably 30 minutes;

[0064] The mixing temperature is preferably 85 to 95°C, more preferably 90°C.

[0065] In the present invention, in step (2), the drying is low-temperature drying; the drying temperature is 10 to 30°C, preferably 15 to 25°C, and more preferably 20°C;

[0066] The drying time is 4 to 6 hours, preferably 4.5 to 5.5 hours, and more preferably 5 hours.

[0067] In the present invention, in step (3), the mixing temperature is preferably 48-52°C, more preferably 50°C.

[0068] The present invention also provides an organic compound fertilizer for improving soda saline-alkali land, comprising the following components: urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate, decomposed poultry and livestock manure and an improver;

[0069] The weight ratio of the urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate, decomposed poultry and livestock manure and the improver is 25-35:18-26:30-40:1-6:30-40:8-14, preferably 28-32:20-24:33-37:3-4:33-37:10-12, and more preferably 30:22:35:3.5:35:11.

[0070] The improver is the improver described.

[0071] In the present invention, the steps of preparing the decomposed livestock excrement are as follows:

[0072] The present invention also provides a method for preparing the organic compound fertilizer, comprising the following steps:

[0073] The improver, urea, diammonium phosphate, potassium sulfate, polyferric sulfate and decomposed poultry and livestock manure are mixed to obtain an organic compound fertilizer.

[0074] The present invention also provides a method for improving soda saline-alkali land, comprising the following steps:

[0075] 1) spreading the organic compound fertilizer in the soda saline-alkali land, ploughing to a depth of 20 to 30 cm, and balancing for 2 to 4 days to obtain the initially treated soda saline-alkali land;

[0076] 2) Irrigate the initially treated soda saline-alkali land and balance it for 5 to 10 days to obtain improved saline-alkali land.

[0077] In the present invention, in step 1), the application rate of the organic compound fertilizer is 150-250 kg / mu, preferably 180-220 kg / mu, and more preferably 200 kg / mu.

[0078] The deep tillage depth is preferably 23 to 27 cm, more preferably 25 cm;

[0079] In step 1), the equilibration time is preferably 3 days.

[0080] In the present invention, in step 2), the irrigation is sprinkler irrigation, and the irrigation amount is 50-80 cm 3 / mu, preferably 60-70cm 3 / mu, more preferably 65cm 3 / mu.

[0081] In step 2), the equilibration time is preferably 6 to 9 days, preferably 8 days.

[0082] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0083] The Bacillus subtilis strain LD1 in the embodiments of the present invention and the comparative examples was purchased from the General Microbiological Center of the China National Microbiological Culture Collection Committee with a deposit number of CGMCC No.14680; Bacillus licheniformis BL-09 was purchased from the General Microbiological Center of the China National Microbiological Culture Collection Committee with a deposit number of CGMCC No.5686; Trichoderma harzianum HN-2 was purchased from the China Center for Type Culture Collection with a deposit number of CCTCC No.M2010119; Bacillus firmus QR-2 was purchased from the General Microbiological Center of the China National Microbiological Culture Collection Committee with a deposit number of CGMCC No.18408; Bacillus megaterium TY006 was purchased from the General Microbiological Center of the China National Microbiological Culture Collection Committee with a deposit number of CGMCC No.11053;

[0084] The livestock manure composting agents in the examples and comparative examples of the present invention were purchased from Henan Yuebao Biotechnology Co., Ltd.

[0085] Example 1 A soda saline-alkali land improver

[0086] Biochar: 100 kg of straw (corn straw and wheat straw mixed in a mass ratio of 1:1) and 100 kg of livestock manure (cow manure and sheep manure mixed in a mass ratio of 1:3) were mixed and calcined at 300 °C to obtain biochar;

[0087] Microbial agent: 1×10 8 CFU / g Bacillus subtilis LD11.5kg, 4×10 7 CFU / g Bacillus licheniformis BL-096kg, 2×10 10 CFU / g Trichoderma harzianum HN-23kg and 6×10 7 CFU / g Bacillus firmus QR-20.75kg was mixed and prepared;

[0088] (1) 8 kg of peat and 16 kg of lignite were mixed and crushed to a particle size of 50 mesh, and then 3 kg of 15% dilute nitric acid was added and mixed at 100° C. for 30 min to obtain activated humic acid;

[0089] (2) 20 kg of biochar, 2 kg of molasses and 8 kg of microbial agent were mixed and low-temperature dried at 20° C. for 5 h to obtain a mixture;

[0090] (3) The mixture, activated humic acid, 10 kg of phosphogypsum and 4 kg of polyglutamic acid were mixed at 50° C. to obtain an improver.

[0091] Example 2 A soda saline-alkali land improver

[0092] Biochar: 100 kg of straw (corn straw and wheat straw mixed at a mass ratio of 1:1.5) and 50 kg of cow dung were mixed and calcined at 250 °C to obtain biochar;

[0093] Microbial agent: 1×10 7 CFU / g Bacillus subtilis LD11kg, 1×10 7 CFU / g Bacillus licheniformis BL-095kg, 5×10 10 CFU / g Trichoderma harzianum HN-21kg and 8×10 7 CFU / g Bacillus firmus QR-20.8kg was mixed and prepared;

[0094] (1) 6 kg of peat, 12 kg of lignite and 12 kg of weathered coal were mixed and crushed to a particle size of 60 mesh, and then 4 kg of 10% dilute nitric acid was added and mixed at 90° C. for 40 min to obtain activated humic acid;

[0095] (2) 15 kg of biochar, 0.8 kg of molasses and 6 kg of microbial agent were mixed and low-temperature dried at 10° C. for 6 h to obtain a mixture;

[0096] (3) The mixture, activated humic acid, 15 kg of phosphogypsum and 6 kg of polyglutamic acid were mixed at 45° C. to obtain an improver.

[0097] Example 3 A soda saline-alkali land improver

[0098] Biochar: 100 kg of straw (corn straw and wheat straw mixed in a mass ratio of 1:1) and 150 kg of livestock manure (cow manure and sheep manure mixed in a mass ratio of 1:2) were mixed and calcined at 400 °C to obtain biochar;

[0099] Microbial agent: 1×10 7 CFU / g Bacillus subtilis LD11kg, 9×10 7 CFU / g Bacillus licheniformis BL-096kg, 1×10 10 CFU / g Trichoderma harzianum HN-23kg and 3×10 7 CFU / g Bacillus firmus QR-20.8kg was mixed and prepared;

[0100] (1) 10 kg of peat and 10 kg of lignite were mixed and crushed to a particle size of 55 mesh, and then 2 kg of 15% dilute nitric acid was added and mixed at 80° C. for 25 min to obtain activated humic acid;

[0101] (2) 25 kg of biochar, 2.4 kg of molasses and 10 kg of microbial agent were mixed and low-temperature dried at 15° C. for 4 h to obtain a mixture;

[0102] (3) The mixture, activated humic acid, 10 kg of phosphogypsum and 8 kg of polyglutamic acid were mixed at 55° C. to obtain an improver.

[0103] Example 4 An organic compound fertilizer for improving soda saline-alkali land

[0104] Preparation of decomposed livestock manure: 0.2 kg of livestock manure composting agent and 100 kg of livestock manure (cow manure and sheep manure mixed in a mass ratio of 1:3) were mixed, piled and fermented at 60° C. for 60 days to obtain decomposed livestock manure;

[0105] 11 kg of the improver described in Example 1, 30 kg of urea, 22 kg of diammonium hydrogen phosphate, 35 kg of potassium sulfate, 3.5 kg of polyferric sulfate and 35 kg of decomposed poultry and livestock manure were mixed to obtain an organic compound fertilizer.

[0106] Example 5 An organic compound fertilizer for improving soda saline-alkali land

[0107] The preparation of decomposed livestock excrement is the same as in Example 4;

[0108] 10 kg of the improver described in Example 2, 28 kg of urea, 24 kg of diammonium hydrogen phosphate, 33 kg of potassium sulfate, 4 kg of polyferric sulfate and 37 kg of decomposed poultry and livestock manure were mixed to obtain an organic compound fertilizer.

[0109] Example 6 An organic compound fertilizer for improving soda saline-alkali land

[0110] The preparation of decomposed livestock excrement is the same as in Example 4;

[0111] 8 kg of the improver described in Example 3, 32 kg of urea, 26 kg of diammonium hydrogen phosphate, 37 kg of potassium sulfate, 3 kg of polyferric sulfate and 33 kg of decomposed poultry and livestock manure were mixed to obtain an organic compound fertilizer.

[0112] Comparative Example 1: An organic compound fertilizer for improving soda saline-alkali land

[0113] Referring to Example 4, the difference from Example 4 is that during the preparation of the improver, no dilute nitric acid is added to activate the humic acid, and the other steps are the same as Example 4.

[0114] Comparative Example 2: An organic compound fertilizer for improving soda saline-alkali land

[0115] Reference Example 4 is different from Example 4 in that: in the process of preparing the improving agent, Bacillus firmus QR-2 is replaced by Bacillus megaterium TY006, and the other steps are the same as Example 4.

[0116] Comparative Example 3: An organic compound fertilizer for improving soda saline-alkali land

[0117] Referring to Example 4, the difference from Example 4 is that in the process of preparing the improver, polyglutamic acid is not added, and the other steps are the same as Example 4.

[0118] Comparative Example 4: An organic compound fertilizer for improving soda saline-alkali land

[0119] Reference Example 4 is different from Example 4 in that: in the process of preparing the organic compound fertilizer, no polyferric sulfate is added, and the other steps are the same as Example 4.

[0120] Comparative Example 5: An organic compound fertilizer for improving soda saline-alkali land

[0121] Reference Example 4 is different from Example 4 in that no modifier is added during the preparation of the organic compound fertilizer, and the other steps are the same as Example 4.

[0122] Example 7 Improvement of soda saline-alkali land

[0123] The experimental field in this embodiment is the Hongqipao experimental base of the Daqing Branch of Heilongjiang Academy of Agricultural Sciences.

[0124] Improvement of soda saline-alkali land:

[0125] 1) Spreading the organic compound fertilizers described in Examples 4 to 6 and Comparative Examples 1 to 5 in the test field at a spreading rate of 200 kg / mu, deep ploughing to 30 cm, and balancing for 3 days to obtain initially treated soda saline-alkali land;

[0126] 2) Sprinkler irrigation is carried out on the initially treated soda saline-alkali land, with a sprinkler irrigation volume of 60m 3 / mu, balanced for 8 days, and the improved saline-alkali land was obtained.

[0127] Corn was planted on the improved saline-alkali land. The corn variety was Tiannong No. 9, and routine management was carried out during the planting process.

[0128] The germination rate of corn was counted, the yield of corn was measured at the maturity stage of corn and soil samples (0-20 cm) were collected. The collected soil samples were naturally air-dried and passed through a 2 mm sieve. The physical and chemical indicators of the soil (pH value, salt content, organic matter, total nitrogen, alkaline potassium, available phosphorus, and effective potassium content) were measured. The measurement results are shown in Tables 1-2.

[0129] Measurement methods of physical and chemical indicators:

[0130] Soil pH value: Soil pH was measured according to the potentiometric method (HJ 962-2018);

[0131] Salt content: calculated by the summation method of eight ions;

[0132] Soil organic matter, alkaline nitrogen, available phosphorus, and quick-acting potassium content: The soil organic matter content was determined by potassium dichromate oxidation-external heating method; the alkaline nitrogen content was measured by alkaline diffusion method; the effective phosphorus content was determined by sodium bicarbonate solution extraction and molybdenum antimony colorimetry; the quick-acting potassium content was determined by ammonium acetate extraction-flame photometer and EDTA-ammonium acetate exchange method;

[0133] Table 1 Physical and chemical properties of soil before and after improvement

[0134]

[0135] Table 2 Germination rate and yield of corn

[0136] Germination rate (%) Yield (kg / mu) Example 4 98.76 678.94 Example 5 98.57 670.86 Example 6 98.43 670.42 Comparative Example 1 76.94 569.83 Comparative Example 2 86.78 598.42 Comparative Example 3 79.37 576.54 Comparative Example 4 85.42 590.97 Comparative Example 5 50.34 406.83

[0137] As shown in Table 1 and Table 2, after the soda saline-alkali land was improved by the organic compound fertilizer described in Examples 4 to 6, the physical and chemical properties of the soil were significantly improved, which was specifically manifested in the decrease of soil pH value, increase of organic matter, alkaline nitrogen, effective phosphorus and available potassium content, and decrease of soil salt content; at the same time, the germination rate and yield of corn planted on the improved saline-alkali land were also significantly improved. In particular, compared with Example 4, the organic compound fertilizer without the addition of the modifier in Comparative Example 5 had a poor improvement effect on the soda saline-alkali land, which further proved the application effect of the modifiers in Examples 1 to 3 and the organic compound fertilizer described in Examples 4 to 6 in the improvement of soda saline-alkali land.

[0138] As can be seen from the above embodiments, the present invention provides a soda saline-alkali land modifier and a preparation method thereof. The prepared modifier can improve the soil structure and physical and chemical properties of the soda saline-alkali land, enhance the adaptability and tolerance of crops to adverse environments, and improve the productivity of the soda saline-alkali land; the present invention prepares the modifier, urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate and decomposed poultry and livestock manure into an organic compound fertilizer, which can not only reduce the salt content and alkali content of the soda saline-alkali land, but also improve the adaptability and tolerance of crops to the adverse environment of the soda saline-alkali land, and promote the growth and development of crops and increase yield.

[0139] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A soda saline-alkali land improver, characterized in that: The invention comprises the following components in parts by weight: 20-30 parts of humic acid, 15-25 parts of biochar, 4-8 parts of polyglutamic acid, 1-4 parts of dilute nitric acid, 8-16 parts of phosphogypsum, 5-10 parts of microbial agent and 0.8-2.4 parts of molasses.

2. The improver according to claim 1, characterized in that The humic acid includes one or more of lignite, weathered coal and peat.

3. The improver according to claim 2, characterized in that The biochar is obtained by calcining organic matter; the organic matter includes straw and / or livestock manure.

4. The improver according to claim 3, characterized in that The microbial agent includes one or more of Bacillus subtilis, Bacillus licheniformis, Trichoderma harzianum and Bacillus firmus.

5. The method for preparing the improver according to any one of claims 1 to 4, characterized in that: The steps include: (1) mixing humic acid and dilute nitric acid at 80-100° C. to obtain activated humic acid; (2) mixing the biochar, molasses, and microbial agent, and drying to obtain a mixture; (3) The mixture, activated humic acid, phosphogypsum and polyglutamic acid are mixed at 45-55° C. to obtain an improver.

6. The preparation method according to claim 5, characterized in that: In step (1), the mixing time is 20 to 40 minutes.

7. The preparation method according to claim 6, characterized in that: In step (2), the drying is low-temperature drying; the drying temperature is 10 to 30° C., and the drying time is 4 to 6 hours.

8. An organic compound fertilizer for improving soda saline-alkali land, characterized in that: The invention comprises the following components: urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate, decomposed poultry and livestock manure and improver; The weight ratio of the urea, diammonium hydrogen phosphate, potassium sulfate, polyferric sulfate, decomposed poultry and livestock manure and the improver is 25-35:18-26:30-40:1-6:30-40:8-14. The improver is the improver according to any one of claims 1 to 4.

9. The method for preparing the organic compound fertilizer according to claim 8, characterized in that: The steps include: The improver, urea, diammonium phosphate, potassium sulfate, polyferric sulfate and decomposed poultry and livestock manure are mixed to obtain an organic compound fertilizer.

10. A method for improving soda saline-alkali land, characterized in that: The steps include: 1) spreading the organic compound fertilizer according to claim 8 in the soda saline-alkali land, ploughing to a depth of 20 to 30 cm, and balancing for 2 to 4 days to obtain the initially treated soda saline-alkali land; 2) Irrigate the initially treated soda saline-alkali land and balance it for 5 to 10 days to obtain improved saline-alkali land.

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