Method for improving saline-alkali soil by using biomass modifier in cooperation with guest soil

Abstract

The present application relates to the technical field of soil improvement, and particularly relates to a method for improving saline-alkali soil by using biomass modifier and guest soil in cooperation. The method for improving saline-alkali soil by using biomass modifier and guest soil in cooperation comprises the following steps: deep ploughing the saline-alkali soil to be improved, uniformly laying the guest soil, then scattering and applying the biomass modifier, and rotary ploughing; and irrigating and leaching salt 1-2 times. The present application can not only reduce the use amount of the guest soil and the engineering improvement cost, but also significantly improve the soil cation exchange capacity by using the biomass modifier, adsorb sodium ions and reduce the alkalization degree. The present application realizes the multi-dimensional cooperation of the guest soil and the biomass modifier, improves the leaching salt efficiency and blocks the salt return channel. The present application can realize the standardization of the plough layer in the same year, the planting and utilization in the same year, forms a short-term and quick-acting and long-term and stable-acting improvement mode, and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a method for synergistically improving saline-alkali land using biomass amendments and imported soil. Background Technology

[0002] Saline-alkali land is a type of salt accumulation, referring to soil where the salt content affects the normal growth of crops. Saline-alkali land can be divided into slightly saline-alkali land, moderately saline-alkali land, and severely saline-alkali land. Its formation is mainly due to the redistribution of various soluble salts in the horizontal and vertical directions on the ground, resulting in the gradual accumulation of salts in the surface layer of the soil in the salt-accumulating area.

[0003] Currently, topsoil mulching is the most common and rapid method for reducing salinity in saline-alkali land improvement. This involves laying low-salinity soil on the surface of the land to create a suitable topsoil environment for cultivation. However, topsoil mulching alone involves a massive amount of work, with high transportation and construction costs. Furthermore, since the topsoil only covers the surface, it fails to block the return of salts from the lower layers via capillary water, leading to frequent salt return and making the improvement effect unsustainable. Ordinary straw, compost, and other organic matter degrade slowly and have few active functional groups, thus reducing their effectiveness in reducing sodium content. ＋ It has weak adsorption and ion exchange capacity; although soil conditioners such as gypsum and phosphogypsum can replace exchangeable sodium on soil colloids through ion exchange and reduce alkalinity, their effect on improving soil structure is limited, soil aggregates recover slowly, water permeability and air permeability are poor, and excessive application can easily cause secondary pollution.

[0004] Saline-alkali soil is a type of degraded soil, and its reclamation is of great significance for solving the world's food problem. Traditional saline-alkali land management is costly and uses a single management model, especially water conservancy and engineering measures, which are even more expensive. Furthermore, crops grown on saline-alkali land yield low output and low income, leading to low enthusiasm for planting.

[0005] In response to the problems of low organic matter content, compaction, dryness, lack of granular structure, limited microbial diversity, and high salinity in saline-alkali soils, the current improvement of saline-alkali land lacks a synergistic mechanism for rapid salt reduction and long-term salt inhibition. Moreover, the improvement cycle is long, the cost is high, and the effective period is short, which has become an urgent technical problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for synergistic improvement of saline-alkali land using biomass conditioners and imported soil.

[0007] A method for synergistically improving saline-alkali land using biomass conditioner and imported soil includes the following steps: deep plowing the saline-alkali land to be improved, evenly spreading imported soil, then applying biomass conditioner, rotary tilling (so that the biomass conditioner and imported soil are evenly combined in the 0-20cm topsoil layer); irrigating with salt 1-2 times.

[0008] Preferably, the imported soil is high-quality topsoil with a salt content ≤1.2g / kg, pH=7.0-8.0, and a texture of medium loam or light loam, which is obtained by removing impurities and then crushing and sieving.

[0009] Preferably, the deep tillage depth is 25-30cm.

[0010] Preferably, the thickness of the topsoil is 10-15cm.

[0011] Preferably, the application rate of the biomass conditioner is 900-1500 kg / mu.

[0012] Preferably, the irrigation water volume is ≥30m³. 3 / mu.

[0013] Preferably, the biomass conditioner is prepared using the following steps: agricultural and forestry waste is crushed, water is added, EM bacteria are introduced, and pre-fermentation is carried out at 30-40℃ for 5-10 days, turning the pile every 2 days during this period. The waste is then dehydrated, dried, and kept in an anaerobic environment at 400-500℃ for 1-2 hours. After cooling to room temperature, the waste is added to a phosphoric acid solution, and urea is added. The mixture is stirred at 60-80℃ for 1-2 hours, filtered, washed, dried, and pulverized. The waste is then added to a Tris-HCl buffer solution with a pH of 8.5-9.5, and dopamine hydrochloride is added and stirred for 2-3 hours. The mixture is then filtered, washed, and added to water. Compound microbial agents and trehalose are added, and the mixture is shaken at 25-30℃ for 1-2 hours. The mixture is then filtered, freeze-dried, and attapulgite powder and humus are added and mixed evenly.

[0014] This invention employs a combination of pre-fermentation and pyrolysis to form multi-level porous biochar, which not only provides a high specific surface area but also promotes ion transport and water migration. Furthermore, a polydopamine coating layer is used to construct a functional interface rich in catechol groups on the biochar surface, enhancing its ion exchange capacity for sodium ions. Simultaneously, it provides a colonization site for microorganisms, immobilizing them to continuously metabolize and produce acid and secrete extracellular polysaccharides in the topsoil, promoting soil aggregate formation and blocking capillary water return channels. Finally, the combination of phosphoric acid and urea introduces phosphate groups and nitrogen-containing functional groups onto the biochar surface, significantly enhancing the absorption of sodium ions from the soil. ＋ Its ion exchange and adsorption capacity can be combined with topsoil covering and irrigation salt leaching to significantly reduce the surface salt content in a short period of time.

[0015] This invention utilizes phosphorus and nitrogen-modified biochar and humus to replenish organic matter, attapulgite powder to enhance water and fertilizer retention, and composite microorganisms to promote soil aggregate structure reconstruction and improve the permeability and aeration of the topsoil, thereby inhibiting salt accumulation at its source. The synergistic effect of these components overcomes the shortcomings of traditional soil improvement measures, such as short-lasting effects and singular methods, achieving long-term and sustainable improvement of saline-alkali land.

[0016] More preferably, the mass ratio of agricultural and forestry waste, EM agent, urea, dopamine hydrochloride, compound microbial agent, trehalose, attapulgite powder, humus, and phosphoric acid solution is 50-80:1-2:2-5:1-5:1-4:0.5-2:2-6:1-5:200-400.

[0017] More preferably, the concentration of the phosphoric acid solution is 5-12 wt%.

[0018] More preferably, after the agricultural and forestry waste is crushed, water is added to adjust the moisture content to 50-70%.

[0019] More preferably, the mass fraction of the phosphoric acid solution is 5-12%.

[0020] More preferably, the agricultural and forestry waste is at least one of corn stalks, wheat stalks, mushroom residue, and branches.

[0021] More preferably, the compound microbial agent includes: Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, Candida utilis, and Halomonas.

[0022] Compared with existing technologies, the present invention has the following advantages: This invention not only reduces the amount of topsoil used and lowers engineering modification costs, but also significantly increases soil cation exchange capacity, adsorbs sodium ions, and reduces alkalinity by utilizing biomass amendments. This invention achieves multi-dimensional synergy between topsoil and biomass amendments, improving salt leaching efficiency and blocking salt return channels. It can achieve the goal of reaching the standard in the same year and be planted and utilized in the same year, forming a short-term rapid effect and a long-term stable effect improvement model, which is suitable for large-scale promotion and application. Attached Figure Description

[0023] Figure 1 This is a comparison chart of pH and organic matter content of soils in Example 5, Comparative Example 1, and Comparative Example 2.

[0024] Figure 2 This is a comparison chart of the topsoil salinity and alkalinity of soils in Example 5, Comparative Example 1, and Comparative Example 2.

[0025] Figure 3 The graph shows a comparison of the survival rate and yield of alfalfa in Example 5, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0027] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0028] The topsoil used below was obtained by removing impurities, crushing, and sieving high-quality topsoil with a salt content of 0.83 g / kg, pH=7.5, and a light loam texture. The EM inoculant used below was purchased from Shandong Yihao Biotechnology Co., Ltd., with a viable bacteria content ≥2 billion CFU / g. The dopamine hydrochloride used below was purchased from Wuhan Fengtai Weiyuan Technology Co., Ltd. The humus soil used below was purchased from Shandong Chenchen Biotechnology Co., Ltd., with a pH of 6.5-7.8, humic acid 7-9%, and organic matter 18-24%.

[0029] The compound microbial agent used below was purchased from Shandong Yihao Biotechnology Co., Ltd., and includes: Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, Candida utilis, and Halomonas; among which, the viable count of Bacillus subtilis is 4 × 10⁻⁶. 9 cfu / g, viable count of Bacillus megaterium was 9 × 10⁻⁶ 8 cfu / g, viable count of Bacillus mucilaginosus was 6 × 10⁻⁶. 8 cfu / g, viable count of Candida utilis was 4 × 10⁻⁶. 8 cfu / g, viable count of Halomonas was 7 × 10⁻⁶ 9 cfu / g. Example 1

[0030] A method for synergistically improving saline-alkali land using biomass conditioner and topsoil includes the following steps: deep plowing of the saline-alkali land to be improved to a depth of 25 cm; evenly spreading a 10 cm thick layer of topsoil, then applying the biomass conditioner (at a rate of 900 kg / mu), followed by rotary tillage; and irrigating once with 30 m³ of water. 3 / mu.

[0031] The biomass conditioner is prepared using the following steps: 50 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 50%. 1 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 30℃ for 5 days, turning it over every 2 days. The mixture is then dehydrated, dried, and kept at 400℃ in an anaerobic environment for 1 hour. After cooling to room temperature, it is added to 200 kg of a 5% (w / w) phosphoric acid solution. 2 kg of urea is added, and the mixture is stirred at 60℃ for 1 hour. The mixture is then filtered, washed, dried, and pulverized through a 100-mesh sieve. Finally, it is added to 200 kg of... Add 1 kg of dopamine hydrochloride to a Tris-HCl buffer solution with pH = 8.5-9.5, stir at 100 r / min for 2 h, filter, wash, and then add to 200 kg of deionized water. Continue to add 1 kg of compound microbial agent and 0.5 kg of trehalose, shake at 25℃ for 1 h, filter, freeze dry, add 2 kg of attapulgite powder and 1 kg of humus soil and mix evenly. Example 2

[0032] A method for synergistically improving saline-alkali land using biomass amendment and topsoil includes the following steps: deep plowing the saline-alkali land to be improved to a depth of 26 cm; evenly spreading a 12 cm thick layer of topsoil, then applying the biomass amendment (at a rate of 1500 kg / mu), followed by rotary tillage; and irrigating once with 50 m³ of water. 3 / mu.

[0033] The biomass conditioner is prepared using the following steps: 80 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 70%. 2 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 40℃ for 10 days, turning it over every 2 days. The mixture is then dehydrated, dried, and kept at 500℃ in an anaerobic environment for 2 hours. After cooling to room temperature, it is added to 400 kg of a 12% phosphoric acid solution. 5 kg of urea is added, and the mixture is stirred at 80℃ for 2 hours. The mixture is then filtered, washed, dried, and pulverized through a 100-mesh sieve. Finally, it is added to 400 kg of... Add 5 kg of dopamine hydrochloride to a Tris-HCl buffer solution with pH = 8.5-9.5, stir at 400 r / min for 3 h, filter, wash, and then add to 400 kg of deionized water. Continue to add 4 kg of compound microbial agent and 2 kg of trehalose, shake at 30℃ for 2 h, filter, freeze dry, add 6 kg of attapulgite powder and 5 kg of humus soil and mix evenly. Example 3

[0034] A method for synergistically improving saline-alkali land using biomass amendment and topsoil includes the following steps: deep plowing the saline-alkali land to be improved to a depth of 28 cm; evenly spreading a 14 cm thick layer of topsoil, then applying the biomass amendment (at a rate of 1000 kg / mu), followed by rotary tillage; and irrigating twice to leach salt, with each application using 35 m³ of water. 3 / mu.

[0035] The biomass conditioner is prepared using the following steps: 70 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 55%. 1.8 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 33℃ for 9 days, turning it over every 2 days. After dehydration and drying, the mixture is kept at 420℃ in an anaerobic environment for 100 minutes, cooled to room temperature, and then added to 260 kg of a 10% phosphoric acid solution. 3 kg of urea is added, and the mixture is stirred at 75℃ for 80 minutes. After filtration, washing, drying, and crushing, the mixture is passed through a 100-mesh sieve. Finally, it is added to 340 kg of... Add 2 kg of dopamine hydrochloride to a Tris-HCl buffer solution with pH = 8.5-9.5, stir at 300 r / min for 140 min, filter, wash, and then add to 340 kg of deionized water. Continue to add 2 kg of compound microbial agent and 1.8 kg of trehalose, shake at 27℃ for 100 min, filter, freeze dry, add 3 kg of attapulgite powder and 4 kg of humus soil and mix evenly. Example 4

[0036] A method for synergistically improving saline-alkali land using biomass amendment and topsoil includes the following steps: deep plowing of the saline-alkali land to be improved to a depth of 29 cm; evenly spreading a 13 cm thick layer of topsoil, then applying a biomass amendment (at a rate of 1400 kg / mu), followed by rotary tillage; and irrigating twice to leach salt, with each application using 45 m³ of water. 3 / mu.

[0037] The biomass conditioner is prepared using the following steps: 60 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 65%. 1.2 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 37℃ for 7 days, turning it over every 2 days. After dehydration and drying, the mixture is kept at 480℃ in an anaerobic environment for 80 minutes, cooled to room temperature, and then added to 340 kg of a 6% phosphoric acid solution. 4 kg of urea is added, and the mixture is stirred at 65℃ for 100 minutes. The mixture is then filtered, washed, dried, and pulverized through a 100-mesh sieve. Finally, it is added to 260 kg of... Add 4 kg of dopamine hydrochloride to a Tris-HCl buffer solution with pH = 8.5-9.5, stir at 200 r / min for 160 min, filter, wash, and then add to 260 kg of deionized water. Continue to add 3 kg of compound microbial agent and 1 kg of trehalose, shake at 29℃ for 80 min, filter, freeze dry, add 5 kg of attapulgite powder and 2 kg of humus soil and mix evenly. Example 5

[0038] A method for synergistically improving saline-alkali land using biomass amendment and topsoil includes the following steps: deep plowing of the saline-alkali land to be improved to a depth of 30 cm; evenly spreading a 15 cm thick layer of topsoil, then applying a biomass amendment (at a rate of 1200 kg / mu), followed by rotary tillage; and irrigating twice to leach salt, with each application using 40 m³ of water. 3 / mu.

[0039] The biomass conditioner is prepared using the following steps: 65 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 60%. 1.5 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 35℃ for 8 days, turning it over every 2 days. After dehydration and drying, the mixture is kept at 450℃ in an anaerobic environment for 90 minutes, cooled to room temperature, and then added to 300 kg of 8% (w / w) phosphoric acid solution. 3.5 kg of urea is added, and the mixture is stirred at 70℃ for 90 minutes. The mixture is then filtered, washed, dried, and pulverized through a 100-mesh sieve. Finally, it is added to 300 kg of... Add 3 kg of dopamine hydrochloride to a Tris-HCl buffer solution with pH = 8.5-9.5, stir at 250 r / min for 150 min, filter, wash, and then add to 300 kg of deionized water. Continue to add 2.5 kg of compound microbial agent and 1.5 kg of trehalose, shake at 28℃ for 90 min, filter, freeze dry, add 4 kg of attapulgite powder and 3 kg of humus soil and mix evenly.

[0040] Comparative Example 1 A method for synergistically improving saline-alkali land using biomass amendment and topsoil includes the following steps: deep plowing of the saline-alkali land to be improved to a depth of 30 cm; evenly spreading a 15 cm thick layer of topsoil, then applying the biomass amendment (at a rate of 1200 kg / mu), followed by rotary tillage; and irrigating twice with 40 m³ of water each time. 3 / mu.

[0041] The biomass conditioner is prepared using the following steps: 65 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 60%. 1.5 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 35℃ for 8 days, turning it over every 2 days. The mixture is then dehydrated, dried, and kept at 450℃ in an anaerobic environment for 90 minutes. After cooling to room temperature, it is pulverized and passed through a 100-mesh sieve. Then, it is added to 300 kg of Tris-HCl buffer solution with a pH of 8.5-9.5. 3 kg of dopamine hydrochloride is added, and the mixture is stirred at 250 r / min for 150 minutes. The mixture is filtered, washed, and then added to 300 kg of deionized water. 2.5 kg of compound microbial inoculant and 1.5 kg of trehalose are added, and the mixture is shaken at 28℃ for 90 minutes. The mixture is then filtered, freeze-dried, and 4 kg of attapulgite powder and 3 kg of humus are added and mixed thoroughly.

[0042] Comparative Example 2 A method for synergistically improving saline-alkali land using biomass amendment and topsoil includes the following steps: deep plowing of the saline-alkali land to be improved to a depth of 30 cm; evenly spreading a 15 cm thick layer of topsoil, then applying the biomass amendment (at a rate of 1200 kg / mu), followed by rotary tillage; and irrigating twice with 40 m³ of water each time. 3 / mu.

[0043] The biomass conditioner is prepared using the following steps: 65 kg of corn stalks are crushed and passed through an 80-mesh sieve. Water is added to adjust the moisture content to 60%. 1.5 kg of EM (Effective Microorganisms) inoculant is added, and the mixture is pre-fermented at 35℃ for 8 days, turning it over every 2 days. The mixture is then dehydrated, dried, and kept at 450℃ in an anaerobic environment for 90 minutes. After cooling to room temperature, it is added to 300 kg of 8% phosphoric acid solution, along with 3.5 kg of urea. The mixture is stirred at 70℃ for 90 minutes, filtered, washed, dried, and pulverized through a 100-mesh sieve. Then, it is added to 300 kg of deionized water, along with 2.5 kg of compound microbial inoculant and 1.5 kg of trehalose. The mixture is shaken at 28℃ for 90 minutes, filtered, freeze-dried, and then 4 kg of attapulgite powder and 3 kg of humus are added and mixed thoroughly.

[0044] A comparative experiment was conducted on a severely soda saline-alkali land in Daqing City, Heilongjiang Province. The severely soda saline-alkali land had a pH of 9.2, a topsoil salt content of 6.3 g / kg, an alkalinity ESP of 32%, and an organic matter content of 7.8 g / kg.

[0045] Alfalfa (Zhongmu No. 3) was used as the test variety, and a split-plot design was adopted so that each plot was 3×3m. After the experimental plot was leveled, the method of Example 5 was used in Example 5, the method of Comparative Example 1 was used in Comparative Example 1, and the method of Comparative Example 2 was used in Comparative Example 2. The seeding rate was 1.75 kg / mu.

[0046] Thirty days later, soil samples were taken from each group using a five-point sampling method (organic matter content was determined according to NY / T 1121.6-2006 "Soil Testing Part 6: Determination of Soil Organic Matter"; topsoil salinity was determined according to NY / T 1121.16-2006 "Soil Testing Part 16: Determination of Total Water-Soluble Salts in Soil"; cation exchange capacity was determined according to NY / T 295-1995 "Determination of Cation Exchange Capacity and Exchangeable Bases in Neutral Soils"; and exchangeable sodium ion content was determined according to NY / T 1121.5-2006 "Soil Testing Part 5: Determination of Cation Exchange Capacity and Exchangeable Bases in Calcareous Soils"). The survival rate of alfalfa was then measured. After the alfalfa was ready for harvest, the yield of each group was measured.

[0047] Basicity = Exchangeable sodium ion content ÷ Cation exchange capacity × 100%.

[0048] like Figure 1 and Figure 2 As shown, the soil in Example 5 group had the lowest pH, the highest organic matter content, and the lowest salt content and alkalinity in the topsoil layer, which was significantly better than the comparative example, confirming that the method in Example 5 can effectively improve the saline-alkali state.

[0049] like Figure 3 As shown, the survival rate and yield of alfalfa in Example 5 were the highest, significantly better than the control group, confirming that the method of Example 5 can effectively improve the saline-alkali state and promote plant growth.

[0050] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A method for synergistically improving saline-alkali land using biomass amendments and imported soil, characterized in that, The process includes the following steps: deep plowing of the saline-alkali land to be improved, evenly spreading topsoil, then applying biomass conditioner, and rotary tilling; irrigating with salt 1-2 times.

2. The method for synergistic improvement of saline-alkali land using biomass amendment and imported soil according to claim 1, characterized in that, The topsoil is made from high-quality topsoil with a salt content of ≤1.2g / kg, pH=7.0-8.0, and a texture of medium loam or light loam. After removing impurities, the topsoil is crushed and sieved.

3. The method for synergistic improvement of saline-alkali land using biomass amendments and imported soil as described in claim 1, characterized in that, The depth of deep plowing is 25-30cm.

4. The method for synergistic improvement of saline-alkali land using biomass amendment and imported soil according to claim 1, characterized in that, The thickness of the topsoil should be 10-15cm.

5. The method for synergistically improving saline-alkali land using biomass amendments and imported soil according to claim 1, characterized in that, The application rate of biomass amendment is 900-1500 kg / mu.

6. The method for synergistic improvement of saline-alkali land using biomass amendment and imported soil according to claim 1, characterized in that, Irrigation water consumption ≥ 30m 3 / mu.

7. The method for synergistically improving saline-alkali land using biomass amendments and imported soil according to claim 1, characterized in that, The biomass conditioner is prepared using the following steps: agricultural and forestry waste is crushed, water is added, EM (Effective Microorganisms) is introduced, and pre-fermentation is carried out at 30-40℃ for 5-10 days, turning the pile every 2 days during this period. After dehydration and drying, the waste is kept in an anaerobic environment at 400-500℃ for 1-2 hours, cooled to room temperature, and then added to a phosphoric acid solution. Urea is added, and the mixture is stirred at 60-80℃ for 1-2 hours. The mixture is then filtered, washed, dried, and pulverized. Next, the mixture is added to a Tris-HCl buffer solution with a pH of 8.5-9.5, and dopamine hydrochloride is added and stirred for 2-3 hours. The mixture is then filtered, washed, and then added to water. Compound microbial agents and trehalose are added, and the mixture is shaken at 25-30℃ for 1-2 hours. The mixture is then filtered, freeze-dried, and attapulgite powder and humus are added and mixed evenly.

8. The method for synergistic improvement of saline-alkali land using biomass amendment and imported soil according to claim 7, characterized in that, The mass ratio of agricultural and forestry waste, EM agent, urea, dopamine hydrochloride, compound microbial agent, trehalose, attapulgite powder, humus, and phosphoric acid solution is 50-80:1-2:2-5:1-5:1-4:0.5-2:2-6:1-5:200-400, wherein the concentration of phosphoric acid solution is 5-12wt%.

9. The method for synergistically improving saline-alkali land using biomass amendments and imported soil according to claim 7, characterized in that, After crushing agricultural and forestry waste, water is added to adjust the moisture content to 50-70%, and the mass fraction of the phosphoric acid solution is 5-12%.

10. The method for synergistic improvement of saline-alkali land using biomass amendment and imported soil according to claim 7, characterized in that, Agricultural and forestry waste includes at least one of corn stalks, wheat stalks, mushroom residue, and branches; compound microbial agents include: Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, Candida utilis, and Halomonas.

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