Soil conditioner for saline-alkali soil

Abstract

The invention relates to a saline-alkali soil conditioner, and relates to the technical field of soil treatment, the saline-alkali soil conditioner comprises the following components by weight: 300-350 parts of modified charcoal, 100-120 parts of blue algae, 1-1.8 parts of modified gamma-polyglutamic acid, 25-30 parts of fly ash, 18-23 parts of a composite microbial preparation, and 5-10 parts of polyacrylamide; the modified biochar is prepared by modifying phosphoric acid and hydrogen peroxide; the modified gamma-polyglutamic acid is prepared through esterification modification. The saline-alkali soil conditioner provided by the invention has the effects of remarkable improvement effect and environmental friendliness.

Description

Technical Field

[0001] The present application relates to the field of soil treatment technology, and in particular to a saline-alkali soil conditioner. Background Art

[0002] Saline-alkali land refers to areas where the salt content in the soil is too high, resulting in an increase in soil pH, destruction of soil structure, and reduced water effectiveness, which in turn affects plant growth. The research and development and application of saline-alkali land conditioners are important technical means to address issues such as the deterioration of the saline-alkali ecological environment, the decline in soil quality, and the restriction of crop growth. With the development of social economy and the high demand for land resources, the development of saline-alkali land conditioners has become the key to improving land productivity, ensuring food security, and improving the ecological environment.

[0003] With the reduction of cultivated land and the decline of soil quality, the management and improvement of saline-alkali land has become an urgent need. At present, different types of saline-alkali land improvers on the market have certain limitations. Chemical improvers are quick to take effect but have potential environmental pollution risks. Biological improvers have little impact on the environment but the improvement effect is easily affected by environmental factors. Organic improvers can effectively improve soil structure but have the problem of incomplete improvement effect. Therefore, it is urgent to develop saline-alkali land improvers with significant effects and good environment. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a saline-alkali soil conditioner.

[0005] The present application provides a saline-alkali soil conditioner, which adopts the following technical solution: A saline-alkali soil conditioner comprises the following components in parts by weight: 300-350 parts of modified biochar, 100-120 parts of cyanobacteria, 1-1.8 parts of modified γ-polyglutamic acid, 25-30 parts of fly ash, 18-23 parts of composite microbial preparations, and 5-10 parts of polyacrylamide; the modified biochar is prepared by modification with phosphoric acid and hydrogen peroxide; and the modified γ-polyglutamic acid is prepared by esterification modification.

[0006] By adopting the above-mentioned technical scheme, the present applicant found during the experiment that after the soil conditioner was applied to the experimental saline-alkali land, the pH value of the experimental saline-alkali land decreased by 2.2-3.1, the salt content decreased by 0.52%-0.64%, and the water content increased by 15.11%-22.84%. This may be because the saline-alkali land soil conditioner can give full play to the synergistic effect between the components, thereby effectively improving the improvement effect on the saline-alkali land, and the amount of polyacrylamide added is small, which improves the environmental friendliness of the saline-alkali land soil conditioner.

[0007] In a specific embodiment, the saline-alkali soil conditioner includes 300 parts of modified biochar, 120 parts of cyanobacteria, 1 part of modified γ-polyglutamic acid, 30 parts of fly ash, 18 parts of composite microbial preparation, and 10 parts of polyacrylamide.

[0008] In a specific embodiment, the saline-alkali soil conditioner includes 320 parts of modified biochar, 105 parts of cyanobacteria, 1.2 parts of modified γ-polyglutamic acid, 29 parts of fly ash, 20 parts of composite microbial preparation, and 6 parts of polyacrylamide.

[0009] In a specific embodiment, the saline-alkali soil conditioner includes 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation, and 7 parts of polyacrylamide.

[0010] In a specific embodiment, the saline-alkali soil conditioner includes 350 parts of modified biochar, 100 parts of cyanobacteria, 1.8 parts of modified γ-polyglutamic acid, 25 parts of fly ash, 23 parts of composite microbial preparation, and 5 parts of polyacrylamide.

[0011] Among them, the saline-alkali land soil conditioner includes 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of polyacrylamide, which is the optimal technical solution. Compared with other technical solutions, the pH value of the improved saline-alkali land is reduced by 0.4-0.5, the salt content is reduced by 0.05%-0.06%, and the water content is increased by 5.63%-6.06%. It is possible that the preferred ratio of the saline-alkali land soil conditioner can give full play to the synergistic effect of the various components, thereby further improving the improvement effect of the saline-alkali land soil conditioner on saline-alkali land.

[0012] Preferably, the preparation method of the modified biochar comprises the following steps: S1, pyrolyzing corn stalks at 350-380°C in an inert gas environment for 1.8-2.2h to obtain biochar; S2, mixing phosphoric acid and hydrogen peroxide and adding them to water to obtain a modified solution, adding the biochar to the modified solution, oscillating at a frequency of 140-160r / min, the oscillation time is 2.5-3.5h, the oscillation temperature is 50-60°C, and then filtering, washing, and drying to obtain the modified biochar; in step S2, the mass concentration of phosphoric acid in the modified solution is 35-42%, the mass concentration of hydrogen peroxide is 10-14%, and the weight ratio of the biochar to the modified solution is (1.5-2):(11-15).

[0013] By adopting the above-mentioned technical scheme, the present application found in the experimental process that the pH value of the saline-alkali land improved by the saline-alkali land soil conditioner made from modified biochar was reduced by 1.2-2.1, the salt content was reduced by 0.22-0.33%, and the water content was increased by 8.56-16.1% compared with the unmodified biochar. This may be because the modified biochar has more acidic groups that can fully reduce the pH of the saline-alkali land, and the modified biochar has rich pore structure and strong adsorption capacity, which can effectively improve the soil structure and increase the permeability of the soil, thereby increasing the water content in the soil and reducing the salt content.

[0014] In a specific embodiment, the mass concentration of phosphoric acid in the modified solution is 42%, and the mass concentration of hydrogen peroxide is 10%.

[0015] In a specific embodiment, the mass concentration of phosphoric acid in the modified solution is 40%, and the mass concentration of hydrogen peroxide is 11%.

[0016] In a specific embodiment, the mass concentration of phosphoric acid in the modified solution is 38%, and the mass concentration of hydrogen peroxide is 12%.

[0017] In a specific embodiment, the mass concentration of phosphoric acid in the modified solution is 35%, and the mass concentration of hydrogen peroxide is 14%.

[0018] Among them, the mass concentration of phosphoric acid in the modified solution is 38%, and the mass concentration of hydrogen peroxide is 12%, which is the best technical solution. Compared with other technical solutions, the pH value of the improved saline-alkali land is reduced by 0.5-0.6, the salt content is reduced by 0.07%-0.08%, and the water content is increased by 6.25%-6.47%. It may be that when the mass concentration of phosphoric acid is 38% and the mass concentration of hydrogen peroxide is 12%, phosphoric acid and hydrogen peroxide can fully exert their synergistic effect, further optimizing the pore structure and the number of acidic groups of the modified biochar, and the components fully exert synergistic effects, thereby further improving the improvement effect of the saline-alkali land soil conditioner on the saline-alkali land.

[0019] In a specific embodiment, the weight ratio of biochar to modified solution is 1.5:15.

[0020] In a specific embodiment, the weight ratio of biochar to modified solution is 1.6:11.

[0021] In a specific embodiment, the weight ratio of biochar to modified solution is 1.7:13.

[0022] In a specific embodiment, the weight ratio of biochar to modified solution is 2:11.

[0023] Among them, the weight ratio of biochar to modified solution is 1.7:13, which is the best technical solution. Compared with other technical solutions, the pH value of the improved saline-alkali land is reduced by 0.8-0.9, the salt content is reduced by 0.09%-0.12%, and the water content is increased by 6.79%-7.54%. It may be that when the weight ratio of biochar to modified solution is 1.7:13, the pore structure and the number of acidic groups of the modified biochar are further optimized, and the synergistic effect between the components is further promoted, thereby further improving the improvement effect of the saline-alkali land soil conditioner.

[0024] Preferably, the preparation method of the modified γ-polyglutamic acid comprises the following steps: a1. stirring γ-glutamic acid and N-methylpyrrolidone in a molar ratio of (2-4):(300-500) at 75-85°C for 11-13h to obtain a mixture; a2. cooling the mixture to 55-65°C, adding sodium bicarbonate, and slowly adding ethyl bromide within 1.8-2.2h, and reacting for 20-30h; a3. taking the supernatant in step a2, adding it to water with a pH value of 1.4-1.6, precipitating, filtering, washing and drying to obtain γ-polyglutamate ethyl ester; the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid in step a2 is (11-14):(14-18):(2-4).

[0025] By adopting the above technical solution, the present application found in the experimental process that when γ-polyglutamic acid was modified by the above technical solution, the pH value of the saline-alkali land improved by the saline-alkali land soil conditioner obtained was reduced by 1.4-2.3, the salt content was reduced by 0.26-0.38%, and the water content was increased by 9.66-17.39%. It may be that the modified γ-polyglutamic acid improves its stability in the saline-alkali environment through esterification reaction. The modified γ-polyglutamic acid keeps the soil soft and permeable in the early stage, which is convenient for salt to penetrate deep into the soil. After degradation in the later stage, it plays a role of water retention and buffering, which is conducive to the modified γ-polyglutamic acid to fully exert its improvement effect and fully cooperate with other components, thereby effectively improving the improvement effect of saline-alkali land.

[0026] In a specific embodiment, the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 14:14:4.

[0027] In a specific embodiment, the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 13:15:3.5.

[0028] In a specific embodiment, the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 12:16:3.

[0029] In a specific embodiment, the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 11:18:2.

[0030] Among them, the optimal technical solution is the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid of 12:16:3. Compared with other technical solutions, the pH value of the improved saline-alkali land is reduced by 0.7-0.9, the salt content is reduced by 0.07%-0.11%, and the water content is increased by 6.47%-7.73%. It may be that when the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 12:16:3, the synergistic effect of modified γ-polyglutamic acid and other components is better, so that the prepared saline-alkali land soil conditioner has a better effect of improving saline-alkali land.

[0031] Preferably, the composite microbial preparation comprises Bacillus licheniformis, Bacillus gelatinus, Pseudomonas tenuifolia and enzyme bacteria in a weight ratio of (8-12):(6-9):(8-14):(4-6).

[0032] By adopting the above technical solution, the present application found in the experimental process that the weight ratio of Bacillus licheniformis, Bacillus jelly, Pseudomonas tenuifolia and enzyme bacteria in the composite microbial preparation is in the range of (8-12):(6-9):(8-14):(4-6) compared with 6:12:6:8 and 14:4:18:2 which are beyond the ratio range, the pH value is reduced by 0.7-1, the salt content is reduced by 0.16-0.2%, and the water content is increased by 3.93-5.86%. It may be that when the weight ratio of Bacillus licheniformis, Bacillus jelly, Pseudomonas tenuifolia and enzyme bacteria is (8-12):(6-9):(8-14):(4-6), the composite microbial preparation can give full play to the synergistic effect, thereby improving the improvement effect on saline-alkali land.

[0033] In a specific embodiment, the weight ratio of Bacillus licheniformis, Bacillus gelatinosa, Pseudomonas tenuissima and Fermentobacterium oxysporum is 8:9:8:6.

[0034] In a specific embodiment, the weight ratio of Bacillus licheniformis, Bacillus gelatinosa, Pseudomonas tenuissima and Fermentobacterium oxysporum is 9:8:10:5.5.

[0035] In a specific embodiment, the weight ratio of Bacillus licheniformis, Bacillus gelatinosa, Pseudomonas tenuissima and Fermentobacterium spp. is 10:7.5:11:5.

[0036] In a specific embodiment, the weight ratio of Bacillus licheniformis, Bacillus gelatinosa, Pseudomonas tenuissima and Fermentobacterium spp. is 12:6:14:4.

[0037] Among them, the weight ratio of Bacillus licheniformis, Bacillus gelatinous, Pseudomonas tenuifolia and enzyme bacteria is 10:7.5:11:5, which is the best technical solution. Compared with other technical solutions, the pH value of the improved saline-alkali land is reduced by 0.5-0.6, the salt content is reduced by 0.05%-0.07%, and the moisture content is increased by 6.19%-6.4%. It may be that when the weight ratio of Bacillus licheniformis, Bacillus gelatinous, Pseudomonas tenuifolia and enzyme bacteria is 10:7.5:11:5, each component can play a more synergistic role, thereby improving the improvement effect of saline-alkali land.

[0038] In summary, this application has the following beneficial technical effects: The present application prepares a saline-alkali land soil conditioner by using a certain proportion of modified biochar, cyanobacteria, modified γ-polyglutamic acid, fly ash, composite microbial preparation and polyacrylamide, and the biochar and γ-polyglutamic acid are modified separately so that the synergistic effect between the components can be fully exerted, the pH value of the saline-alkali land is reduced, the salt content of the saline-alkali land is reduced and the water content of the saline-alkali land is increased. The effect of improving the saline-alkali land is significant, the amount of polyacrylamide added is small, and it has the characteristics of being environmentally friendly. DETAILED DESCRIPTION

[0039] The specific embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.

[0040] Material Source Corn straw was purchased from Yongjia Grass Industry in Zhengyang County; Cyanobacteria were purchased from Guangdong Meixian Meiyan Cyanobacteria Co., Ltd.; Phosphoric acid, hydrogen peroxide, and sodium bicarbonate were purchased from Qingzhou Xinsheng Chemical Co., Ltd.; Fly ash was purchased from Lingshou County Shengyun Mineral Products Processing Plant, with a silicon dioxide content of 45%-65%, first-class product; Polyacrylamide was purchased from Shandong DeLan Chemical Co., Ltd.; N-Methylpyrrolidone was purchased from Shanghai Kaiyin Chemical Co., Ltd.; Ethyl bromide was purchased from Weifang Nuohai Chemical Co., Ltd.; Dodecanol and ethanol were purchased from Shanghai Better Chemical Co., Ltd.; γ-Glutamic acid, Bacillus licheniformis, Bacillus gelatinus, Pseudomonas tenuissima and Fermentobacterium zymosanus were purchased from Guangzhou True Microbiology Technology Co., Ltd.

[0041] Preparation Example 1.1 The preparation of modified biochar includes the following steps: S1. Place the quartz ark filled with corn stalks into a tube furnace and pyrolyze it at 350 °C in a nitrogen environment for 2.2 h to obtain biochar; S2. Mix 485.6 ml of phosphoric acid and 248.5 ml of hydrogen peroxide and add them to 1326 ml of water to prepare a modified solution. Add 340 g of biochar to the modified solution, oscillate at a frequency of 160 r / min for 2.5 hours at a temperature of 50°C, then filter, wash with water until the pH is close to 7.0, and then dry at 105°C for 24 hours to obtain modified biochar.

[0042] Preparation Example 1.2 The preparation of modified biochar includes the following steps: S1. Place the quartz ark filled with corn stalks into a tube furnace and pyrolyze at 380 °C in a nitrogen environment for 1.8 h to obtain biochar; S2. Mix 582.7 ml of phosphoric acid and 177.5 ml of hydrogen peroxide and add them to 1248 ml of water to prepare a modified solution. Add 340 g of biochar to the modified solution, oscillate at a frequency of 140 r / min for 3.5 hours at a temperature of 60°C, then filter, wash with water until the pH is close to 7.0, and then dry at 105°C for 24 hours to obtain modified biochar.

[0043] Preparation Example 1.3 The difference from Preparation Example 1.1 is that in step S2, phosphoric acid is 527.2 ml, hydrogen peroxide is 213 ml, and water is 1300 ml.

[0044] Preparation Example 1.4 The difference from Preparation Example 1.1 is that in step S2, phosphoric acid is 416.2 ml, hydrogen peroxide is 354.9 ml, and water is 1300 ml.

[0045] Preparation Example 1.5 The difference from Preparation Example 1.1 is that in step S2, phosphoric acid is 693.7 ml, hydrogen peroxide is 88.74 ml, and water is 1300 ml.

[0046] Preparation Example 2.1 The difference from Preparation Example 1.3 is that the weight of biochar in step S2 is 260 g.

[0047] Preparation Example 2.2 The difference from Preparation Example 1.3 is that the weight of biochar in step S2 is 472.7 g.

[0048] Preparation Example 2.3 The difference from Preparation Example 1.3 is that the weight of biochar in step S2 is 780 g.

[0049] Preparation Example 2.4 The difference from Preparation Example 1.3 is that the weight of biochar in step S2 is 130 g.

[0050] Preparation Example 3.1 The preparation of modified γ-polyglutamic acid comprises the following steps: a1. 29.43 g of γ-glutamic acid and 4821.5 ml of N-methylpyrrolidone were stirred at 85 ° C for 11 h to obtain a mixture; a2. The mixture was cooled to 65 ° C, 95.41 g of sodium bicarbonate was added, and 134.3 ml of ethyl bromide was slowly added within 1.8 h, and the reaction was continued for 30 h; a3. Take the supernatant in step a2, add it to 1500ml of water with a pH value of 1.4, precipitate, filter, wash with cold water and ether and dry in vacuo to obtain γ-polyethyl glutamate.

[0051] Preparation Example 3.2 The preparation of modified γ-polyglutamic acid comprises the following steps: a1. 58.85 g of γ-glutamic acid and 2892.9 ml of N-methylpyrrolidone were stirred at 75 ° C for 13 h to obtain a mixture; a2. The mixture was cooled to 55 ° C, 117.6 g of sodium bicarbonate was added, and 104.5 ml of ethyl bromide was slowly added within 2.2 h, and the reaction was continued for 30 h; a3. Take the supernatant in step a2, add it to 1500ml of water with a pH value of 1.6, precipitate, filter, wash with cold water and ether and dry in vacuo to obtain γ-polyethyl glutamate.

[0052] Preparation Example 3.3 The difference from Preparation Example 3.1 is that in step a2, the amount of sodium bicarbonate is 67.21 g and the amount of ethyl bromide is 79.6 ml.

[0053] Preparation Example 3.4 The difference from Preparation Example 3.1 is that in step a2, the amount of sodium bicarbonate is 134.4 g and the amount of ethyl bromide is 328.4 ml.

[0054] Preparation Example 3.5 The difference from Preparation Example 3.1 is that in step a2, the amount of sodium bicarbonate is 37.8 g and the amount of ethyl bromide is 186.6 ml.

[0055] Example 1.1 The saline-alkali soil conditioner includes: 300g modified biochar, 120g cyanobacteria, 1g modified γ-polyglutamic acid, 30g fly ash, 18g composite microbial preparation and 10g polyacrylamide, the modified biochar is the modified biochar prepared in Preparation Example 1.3, the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Example 3.3, and the composite microbial preparation includes 5.37g Bacillus licheniformis, 4.03g Bacillus gelatinus, 5.91g Pseudomonas tenuifolia and 2.69g enzyme bacteria.

[0056] Example 1.2 The saline-alkali soil conditioner includes: 350g modified biochar, 100g cyanobacteria, 1.8g modified γ-polyglutamic acid, 25g fly ash, 23g composite microbial preparation and 5g polyacrylamide, the modified biochar is the modified biochar prepared in Preparation Example 1.3, the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Example 3.3, and the composite microbial preparation includes 6.87g Bacillus licheniformis, 5.15g Bacillus gelatinus, 7.55g Pseudomonas tenuifolia and 3.43g enzyme bacteria.

[0057] Example 1.3 The saline-alkali soil conditioner includes: 330g modified biochar, 110g cyanobacteria, 1.5g modified γ-polyglutamic acid, 27g fly ash, 20g composite microbial preparation and 7g polyacrylamide, the modified biochar is the modified biochar prepared in Preparation Example 1.3, the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Example 3.3, and the composite microbial preparation includes 5.97g Bacillus licheniformis, 4.48g Bacillus gelatinus, 6.57g Pseudomonas aeruginosa and 2.99g enzyme bacteria.

[0058] Examples 2.1-2.2 The difference from Example 1.3 is that the modified biochars are the modified biochars prepared in Preparation Examples 1.1-1.2 respectively.

[0059] Example 2.3-2.4 The difference from Example 1.3 is that the modified biochar is the modified biochar prepared in Preparation Examples 1.4-1.5 respectively.

[0060] Examples 3.1-3.4 The difference from Example 1.3 is that the modified biochars are the modified biochars prepared in Preparation Examples 2.1-2.4 respectively.

[0061] Examples 4.1-4.2 The difference from Example 1.3 is that the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Examples 3.1-3.2 respectively.

[0062] Examples 4.3-4.4 The difference from Example 1.3 is that the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Examples 3.4-3.5 respectively.

[0063] Example 5.1 The difference from Example 1.3 is that the composite microbial preparation includes 4.65g of Bacillus licheniformis, 5.23g of Bacillus gelatinus, 4.65g of Pseudomonas tenuissima and 3.48g of enzyme bacteria.

[0064] Example 5.2 The difference from Example 1.3 is that the composite microbial preparation includes 6g of Bacillus licheniformis, 3g of Bacillus gelatinus, 7g of Pseudomonas tenuissima and 2g of enzyme bacteria.

[0065] Example 5.3 The difference from Example 1.3 is that the composite microbial preparation includes 3.375 g of Bacillus licheniformis, 6.75 g of Bacillus gelatinus, 3.375 g of Pseudomonas tenuissima and 4.5 g of enzyme bacteria.

[0066] Example 5.4 The difference from Example 1.3 is that the composite microbial preparation includes 6.63g of Bacillus licheniformis, 1.89g of Bacillus gelatinus, 8.53g of Pseudomonas tenuissima and 0.95g of enzyme bacteria.

[0067] Comparative Example 1.1 The saline-alkali soil conditioner includes: 250g modified biochar, 140g cyanobacteria, 0.5g modified γ-polyglutamic acid, 50g fly ash, 10g composite microbial preparation and 20g polyacrylamide, the modified biochar is the modified biochar prepared in Preparation Example 1.3, the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Example 3.3, and the composite microbial preparation includes 2.99g Bacillus licheniformis, 2.24g Bacillus gelatinus, 3.28g Pseudomonas tenuifolia and 1.49g enzyme bacteria.

[0068] Comparative Example 1.2 The saline-alkali soil conditioner includes: 400g modified biochar, 80g cyanobacteria, 2.5g modified γ-polyglutamic acid, 15g fly ash, 30g composite microbial preparation and 2g polyacrylamide, the modified biochar is the modified biochar prepared in Preparation Example 1.3, the modified γ-polyglutamic acid is the modified γ-polyglutamic acid prepared in Preparation Example 3.3, and the composite microbial preparation includes 8.96g Bacillus licheniformis, 6.72g Bacillus gelatinus, 9.85g Pseudomonas tenuifolia and 4.48g enzyme bacteria.

[0069] Comparative Example 2.1 The difference from Example 1.3 is that the modified biochar is replaced by an equal amount of unmodified biochar.

[0070] Comparative Example 2.2 The difference from Example 1.3 is that the modified γ-polyglutamic acid is replaced by an equal amount of unmodified γ-polyglutamic acid.

[0071] Performance Testing The saline-alkali soil conditioner obtained in the embodiment and the comparative example was added to the saline-alkali land at an application rate of 200 kg / mu, and the performance test was carried out according to GB / T8576, NY / T1973, and NY / T1121.11-2006 standards. The pH value of the unimproved saline-alkali land was 9.7, the salt content was 0.73%, and the water content was 10.38%. The test results are shown in Table 1.

[0072] Table 1 Test results

[0073] As can be seen from Table 1, the saline-alkali soil conditioner provided in Example 1.3 of the present application is used for improving saline-alkali land, so that the pH value of the improved saline-alkali land is 6.6, the salt content is 0.09%, and the moisture content is 33.22%, indicating that the saline-alkali soil conditioner provided in Example 1.3 of the present application has a significant effect on improving saline-alkali land.

[0074] The saline-alkali soil conditioner provided in Examples 1.1 and 1.2 of the present application is used for saline-alkali land improvement. Compared with the pH value in Example 1.3 of the present application, it is increased by 0.4 and 0.5 respectively, the salt content is increased by 0.05% and 0.06% respectively, and the water content is reduced by 5.63% and 6.06% respectively, indicating that the saline-alkali soil conditioner prepared according to the preferred weight ratio of 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of polyacrylamide provided in the present application has a better effect of improving saline-alkali land.

[0075] The saline-alkali soil conditioner provided in Examples 2.1 and 2.2 of the present application is used for saline-alkali land improvement. Compared with the pH value in Example 1.3 of the present application, the pH value is increased by 0.6 and 0.5 respectively, the salt content is increased by 0.08% and 0.07% respectively, and the water content is reduced by 6.47% and 6.25% respectively, indicating that the saline-alkali soil conditioner prepared according to the preferred weight ratio of 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of polyacrylamide provided in the present application, and the mass concentration of phosphoric acid in the modified solution is 38%, and the mass concentration of hydrogen peroxide is 12% has a better effect of improving saline-alkali land.

[0076] Compared with Example 2.1, the pH values ​​of Examples 2.3 and 2.4 of the present application are increased by 1 and 0.9, respectively, the salt contents are increased by 0.19% and 0.2%, respectively, and the moisture contents are decreased by 5.74% and 6.57%, respectively. Compared with Example 2.1, the pH values ​​of Examples 2.3 and 2.4 of the present application are increased by 1.1 and 1.2, respectively, the salt contents are increased by 0.2% and 0.21%, respectively, and the moisture contents are decreased by 5.96% and 6.79%, respectively. This indicates that the modified biochar prepared when the mass concentration range of phosphoric acid in the modified solution provided in the present application is 35-42%, and the mass concentration range of hydrogen peroxide is 10-14% has a good effect on improving the improvement effect of saline-alkali soil conditioner.

[0077] Compared with Example 1.3, the pH values ​​of Examples 3.1 and 3.2 of the present application were increased by 0.8 and 0.9, respectively, the salt contents were increased by 0.09% and 0.12%, respectively, and the moisture contents were decreased by 6.79% and 7.54%, respectively, indicating that the saline-alkali land soil conditioner prepared according to the preferred weight ratio of 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of polyacrylamide provided in the present application, the mass concentration of phosphoric acid in the modified solution is 38%, the mass concentration of hydrogen peroxide is 12%, and the weight ratio of biochar to modified solution is 1.7:13 has a better effect of improving saline-alkali land.

[0078] Compared with Example 3.1, the pH values ​​of Examples 3.3 and 3.4 of the present application were increased by 0.7 and 0.5, respectively, the salt contents were increased by 0.17% and 0.13%, respectively, and the water contents were decreased by 4.98% and 3.38%, respectively. Compared with Example 3.2, the pH values ​​of Examples 3.3 and 3.4 of the present application were increased by 0.6 and 0.4, respectively, the salt contents were increased by 0.14% and 0.1%, respectively, and the water contents were decreased by 4.23% and 2.63%, respectively. This indicates that when the weight ratio of biochar to modified solution provided in the present application is in the range of (1.5-2):(11-15), the obtained saline-alkali land soil conditioner has a good effect of improving saline-alkali land.

[0079] Compared with Example 1.3, the pH values ​​of Examples 4.1 and 4.2 of the present application were increased by 0.7 and 0.9, respectively, the salt contents were increased by 0.07% and 0.11%, respectively, and the moisture contents were decreased by 6.47% and 7.73%, respectively, indicating that when the saline-alkali land soil conditioner is a preferred weight ratio of 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of polyacrylamide, the mass concentration of phosphoric acid in the modified solution is 38%, the mass concentration of hydrogen peroxide is 12%, the weight ratio of biochar to modified solution is 1.7:13, and the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 12:16:3, the obtained saline-alkali land soil conditioner has a better effect of improving saline-alkali land.

[0080] Compared with Example 4.1, the pH values ​​of Examples 4.3 and 4.4 of the present application were increased by 0.9 and 1, respectively, the salt contents were increased by 0.2% and 0.21%, respectively, and the moisture contents were decreased by 5.96% and 6.63%, respectively. Compared with Example 4.2, the pH values ​​of Examples 4.3 and 4.4 of the present application were increased by 0.7 and 0.80, respectively, the salt contents were increased by 0.16% and 0.17%, respectively, and the moisture contents were decreased by 4.7% and 5.37%, respectively. This indicates that when the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is (11-14):(14-18):(2-4), the obtained modified γ-polyglutamic acid has an excellent effect on improving the improvement effect of saline-alkali soil conditioner.

[0081] Compared with Example 1.3, the pH values ​​of Examples 5.1 and 5.2 of the present application are increased by 0.5 and 0.6, respectively, the salt contents are increased by 0.05% and 0.07%, respectively, and the moisture contents are decreased by 6.19% and 6.4%, respectively, indicating that when the saline-alkali land soil conditioner is a preferred weight ratio of 330 parts of modified biochar, 110 parts of cyanobacteria, 1.5 parts of modified γ-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of polyacrylamide, the mass concentration of phosphoric acid in the modified solution is 38%, the mass concentration of hydrogen peroxide is 12%, the weight ratio of biochar to the modified solution is 1.7:13, the molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid is 12:16:3, and the weight ratio of Bacillus licheniformis, Bacillus gelatinus, Pseudomonas tenuifolia and enzyme bacteria is 10:7.5:11:5, the obtained saline-alkali land soil conditioner has a better effect of improving saline-alkali land.

[0082] Compared with Example 5.1, the pH values ​​of Examples 5.3 and 5.4 of the present application are increased by 0.8 and 1, respectively, the salt contents are increased by 0.18% and 0.2%, respectively, and the moisture contents are decreased by 4.14% and 5.86%, respectively. Compared with Example 5.2, the pH values ​​of Examples 5.3 and 5.4 of the present application are increased by 0.7 and 0.9, respectively, the salt contents are increased by 0.16% and 0.18%, respectively, and the moisture contents are decreased by 3.93% and 5.65%, respectively. This indicates that when the weight ratio of Bacillus licheniformis, Bacillus gelatinus, Pseudomonas aeruginosa and enzyme bacteria is in the range of (8-12):(6-9):(8-14):(4-6), the obtained saline-alkali land soil conditioner has an excellent effect of improving saline-alkali land.

[0083] Compared with Example 1.1, the pH values ​​of Comparative Examples 1.1 and 1.2 of the present application are respectively increased by 1.5 and 1.4, the salt contents are respectively increased by 0.26% and 0.25%, and the moisture contents are respectively decreased by 9.35% and 7.95%. Compared with Example 1.2, the pH values ​​of Comparative Examples 1.1 and 1.2 of the present application are respectively increased by 1.6 and 1.5, the salt contents are respectively increased by 0.25% and 0.24%, and the moisture contents are respectively decreased by 8.92% and 7.52%, indicating that when the saline-alkali land soil conditioner includes 300-350 parts of modified biochar, 100-120 parts of cyanobacteria, 1-1.8 parts of modified γ-polyglutamic acid, 25-30 parts of fly ash, 18-23 parts of composite microbial preparation and 5-10 parts of polyacrylamide, the obtained saline-alkali land soil conditioner has an excellent effect of improving saline-alkali land.

[0084] Compared with Example 1.3, the pH value of Comparative Example 2.1 of the present application increased by 2.1, the salt content increased by 0.33%, and the moisture content decreased by 16.1%, indicating that the modified biochar has a significant effect on improving the improvement effect of saline-alkali land soil conditioner.

[0085] Compared with Example 1.3, the pH value of Comparative Example 2.2 of the present application increased by 2.3, the salt content increased by 0.38%, and the water content decreased by 17.39%, indicating that modified γ-polyglutamic acid has a significant effect on improving the improvement effect of saline-alkali land soil conditioner.

Claims

1. A saline-alkali soil conditioner, characterized in that: The invention comprises the following components in parts by weight: 300-350 parts of modified biochar, 100-120 parts of cyanobacteria, 1-1.8 parts of modified gamma-polyglutamic acid, 25-30 parts of fly ash, 18-23 parts of composite microbial preparation and 5-10 parts of polyacrylamide; the modified biochar is prepared by modification with phosphoric acid and hydrogen peroxide; the modified gamma-polyglutamic acid is prepared by esterification modification.

2. The saline-alkali soil conditioner according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 330 parts of modified biochar, 110 parts of blue algae, 1.5 parts of modified gamma-polyglutamic acid, 27 parts of fly ash, 20 parts of composite microbial preparation and 7 parts of modified polyacrylamide.

3. The saline-alkali soil conditioner according to claim 1, characterized in that: The preparation method of the modified biochar comprises the following steps: S1, pyrolyzing corn straw at 350-380°C in an inert gas environment for 1.8-2.2h to obtain biochar; S2. Phosphoric acid and hydrogen peroxide are mixed and added to water to prepare a modified solution, biochar is added to the modified solution, and the solution is oscillated at a frequency of 140-160 r / min for 2.5-3.5 h at a temperature of 50-60° C., and then filtered, washed, and dried to obtain modified biochar; In the step S2, the mass concentration of phosphoric acid in the modified solution is 35-42%, the mass concentration of hydrogen peroxide is 10-14%, and the weight ratio of the biochar to the modified solution is (1.5-2):(11-15).

4. The saline-alkali soil conditioner according to claim 3, characterized in that: The mass concentration of the phosphoric acid in step S2 is 38%, and the mass concentration of the hydrogen peroxide is 12%.

5. The saline-alkali soil conditioner according to claim 3, characterized in that: The weight ratio of the biochar to the modified solution in step S2 is 1.7:

13.

6. The saline-alkali soil conditioner according to claim 1, characterized in that: The preparation method of the modified γ-polyglutamic acid comprises the following steps: a1. The molar ratio of (2-4): (300-500) of γ-glutamic acid and N-methylpyrrolidone was stirred at 75-85 ° C for 11-13h to obtain a mixture; a2. Cool the mixture to 55-65°C, add sodium bicarbonate, and slowly add ethyl bromide within 1.8-2.2h, and react for 20-30h; a3. Take the supernatant in step a2, add it to water having a pH value of 1.4-1.6, precipitate, filter, wash and dry to obtain γ-polyethyl glutamate; The molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid in step a2 is (11-14):(14-18):(2-4).

7. The saline-alkali soil conditioner according to claim 6, characterized in that: The molar ratio of sodium bicarbonate, ethyl bromide and γ-glutamic acid in step a2 is 12:16:

3.

8. The saline-alkali soil conditioner according to claim 1, characterized in that: The composite microbial preparation comprises Bacillus licheniformis, Bacillus gelatinus, Pseudomonas tenuifolia and enzyme bacteria in a weight ratio of (8-12):(6-9):(8-14):(4-6).

9. The saline-alkali soil conditioner according to claim 8, characterized in that: The weight ratio of the Bacillus licheniformis, the Bacillus gelatinus, the Pseudomonas tenuifolia and the enzyme bacteria is 10:7.5:11:5.

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