A saline-alkali soil conditioner for soybean cultivation and a method of applying the same

Abstract

The application discloses a saline-alkali soil conditioner suitable for soybean cultivation and an application method thereof. The conditioner is composed of 70% of rotten cow manure, 25% of superphosphoric acid calcium, 5% of ferrous sulfate and 1000 ppm of ammonium molybdate. Through the synergistic effect of "organic fertilization + inorganic salt adjustment + micro-fertilizer synergism", the problems of poor structure, high salt content, strong alkalinity, low fertility and serious nutrient deficiency of the saline-alkali soil are solved simultaneously. In the preparation, the dry-wet mixing combination and medium-temperature fermentation process are adopted, and in the application, the conditioner is applied in stages according to the degree of salinization (0.2-0.6% of the adding amount), and is matched with rotary tillage and water management. The experiment shows that after the application, the soil pH is reduced to 7.0-7.7, the effective molybdenum is increased by 3.5 times, the soybean emergence rate is increased by 22%, and the biomass is increased by 35%. The application is especially suitable for soybean planting in the coastal saline-alkali land with pH of 8.0-9.5, and realizes the synergistic optimization of soil improvement and crop growth.

Description

Technical Field

[0001] This invention relates to the field of saline-alkali land improvement and agricultural planting technology, specifically to a saline-alkali soil conditioner with livestock and poultry waste as the core raw material, adapted to the growth needs of soybeans, and its application method, which is particularly suitable for soybean cultivation improvement in coastal saline-alkali land and similar saline-alkali soils. Background Technology

[0002] The core technical bottleneck in soybean cultivation in coastal saline-alkali land is the insufficient compatibility between the soil environment and the growth requirements of soybeans: First, the soil is highly alkaline, with the original soil pH generally above 8.0, exceeding the slightly acidic to neutral (pH 6.0-7.0) growth range preferred by soybeans, thus inhibiting root activity and nutrient absorption; second, the soil structure is compacted, with a bulk density as high as 1.36-1.38 g / cm³. 3 First, the field water holding capacity is only about 29%, resulting in poor water permeability and aeration, which affects soybean seed germination and root extension. Second, the soil is deficient and unbalanced in nutrients, with an organic matter content of only 6.43 g / kg, available phosphorus of only 1.46 mg / kg, and available nitrogen of 37.8 mg / kg. It also lacks essential micronutrients for soybeans, such as molybdenum and iron (available molybdenum 0.74 mg / kg and available iron 19.45-19.77 mg / kg). Molybdenum is a core component of nitrogenase in root nodules, and iron participates in chlorophyll synthesis. The deficiency of both directly restricts the nitrogen fixation capacity and photosynthetic efficiency of soybeans. Third, there is the risk of salt stress, with a soil electrical conductivity of 465 μS / cm and an exchangeable sodium content of 0.47 cmol+ / kg. The high salt environment easily leads to low soybean emergence rate and stunted growth.

[0003] While existing saline-alkali soil conditioners have evolved into various products, including organic, inorganic, and compound types, they lack specificity for soybean cultivation and exhibit significant technical shortcomings. Organic conditioners often use only livestock manure or straw as raw materials, lacking targeted salt-regulating and alkali-reducing components, making it difficult to address high sodium and strong alkalinity issues. Inorganic conditioners, such as single superphosphate or gypsum, can only address specific soil problems (e.g., phosphorus supplementation or sodium reduction), failing to simultaneously improve soil structure and supplement micronutrients. Compound conditioners generally suffer from poor formulation synergy, lack of targeted micronutrient ratios, and ambiguous application thresholds. High-dose application can easily trigger secondary soil salinization, while low-dose application yields incomplete improvement, making it difficult to meet the full-cycle needs of soybeans from germination to growth to nitrogen fixation. Therefore, developing a saline-alkali soil conditioner that synergistically combines organic fertilization, inorganic salt regulation, and micronutrient enhancement, and is tailored to the specific needs of soybeans, is crucial to overcoming the technical bottlenecks in soybean cultivation in coastal saline-alkali areas. Summary of the Invention

[0004] Addressing the core shortcomings of existing saline-alkali soil conditioners, such as "fragmented functions, insufficient targeting of trace elements, ambiguous dosage thresholds, and poor organic-inorganic synergy," and considering the specific needs of soybean cultivation in coastal saline-alkali land, the objectives of this invention are as follows:

[0005] This invention provides a compound conditioner that synergistically combines organic enrichment, inorganic salt regulation, and micronutrient enhancement, simultaneously addressing five major challenges of saline-alkali soil: poor structure, high salinity, strong alkalinity, low fertility, and lack of micronutrients. This achieves precise matching between soil physical structure, chemical properties, and soybean growth requirements.

[0006] This product provides targeted supplementation of essential trace elements such as molybdenum and iron for soybean growth, combined with pH control technology to enhance the availability of these trace elements, thereby strengthening soybean's nitrogen fixation capacity and photosynthetic efficiency and addressing the problem of poor nutrient compatibility in existing products.

[0007] By clearly defining the optimal dosage range (0.2%-0.6%) of the conditioner and differentiating application schemes, we can avoid both incomplete improvement with low doses and the risk of salt stress with high doses, thus achieving a three-dimensional balance of "efficacy-cost-safety".

[0008] By scientifically combining well-rotted cow manure, superphosphate, ferrous sulfate, and ammonium molybdate, and leveraging the synergistic effects of each component (well-rotted cow manure increases organic matter, superphosphate reduces sodium and supplements phosphorus, ferrous sulfate lowers pH and supplements iron, and ammonium molybdate enhances nitrogen fixation), an integrated solution for saline-alkali land improvement and soybean nutrient supply is constructed, thereby improving soybean emergence rate, biomass, and nutrient absorption efficiency.

[0009] The technical solution of the present invention is as follows:

[0010] A soil conditioner for saline-alkali soil suitable for soybean cultivation, comprising the following components by weight percentage:

[0011] 70% well-rotted cow manure

[0012] 25% superphosphate

[0013] 5% ferrous sulfate

[0014] Ammonium molybdate 1000 ppm, based on the total mass of the conditioner.

[0015] In the above technical solution, the moisture content of the decomposed cow manure is ≤30%, and it is crushed and passed through a 20-mesh sieve;

[0016] The superphosphate has an effective phosphorus content of ≥16% and is pulverized through a 40-mesh sieve.

[0017] The ferrous sulfate mentioned is industrial grade ferrous sulfate heptahydrate.

[0018] In the above technical solution, the ammonium molybdate is first dissolved into a 5% aqueous solution before being mixed with other components.

[0019] In the above technical solution, the preparation method of the saline-alkali soil conditioner includes the following steps:

[0020] (1) Raw material pretreatment: crush well-rotted cow manure through a 20-mesh sieve, and crush superphosphate and ferrous sulfate through a 40-mesh sieve respectively;

[0021] (2) Dry mixing: Mix the pretreated solid raw materials in proportion and stir for 5-8 minutes;

[0022] (3) Wet mixing: Add ammonium molybdate aqueous solution and continue stirring for 10 minutes;

[0023] (4) Medium temperature fermentation: Ferment at 55-60℃ for 7-10 days, turning the pile once every 48 hours during the period;

[0024] (5) Post-processing: The fermentation product is crushed and passed through a 30-mesh sieve. After passing the test, it is packaged.

[0025] In the above technical solution, during the fermentation process in step (4), the height of the pile is controlled at 1.2-1.5m and covered with a breathable film;

[0026] The final fermentation pH is 6.5-7.0, and the total salt content is ≤3%.

[0027] In the above technical solution, the application method of the saline-alkali soil conditioner includes:

[0028] (1) Soil testing: Determine the pH, electrical conductivity and exchangeable sodium content of the soil to be improved;

[0029] (2) Differentiated application:

[0030] Slightly saline-alkali soil with a pH of 8.0-8.5: Addition amount 0.2-0.3%;

[0031] For moderately saline-alkali soil with a pH of 8.5-9.0: add 0.4-0.5%;

[0032] For severely saline-alkali soil with pH > 9.0: apply 0.6% additive first, and then apply 0.2% maintenance amount 2 weeks later;

[0033] (3) Rotary tillage and mixing: After application, rotary tillage to a depth of 15-20cm;

[0034] (4) Water management: Irrigate with 30 mm of water within 24 hours after application.

[0035] In the above technical solution, a 0.1% ammonium molybdate solution is sprayed on the leaves during the soybean flowering period, with a dosage of 20-30 L / mu.

[0036] In the above technical solution, the exchangeable sodium content of the slightly saline-alkali soil is <0.5 cmol+ / kg;

[0037] The exchangeable sodium content of the severely saline-alkali soil is ≥0.8 cmol+ / kg.

[0038] A method for cultivating soybeans in saline-alkali land includes:

[0039] Apply soil conditioner as described above 15 days before sowing;

[0040] Sow salt-tolerant soybean varieties at a density of 180,000-220,000 plants / hectare;

[0041] Foliar application of molybdenum fertilizer during the flowering period.

[0042] In the above technical solution, the salt-tolerant soybean variety is "Zhonghuang 301" or "Jidou 12".

[0043] Beneficial effects

[0044] 1. Innovative formula ratio: The formula uses a precise ratio of well-rotted cow manure (70%), superphosphate (25%), ferrous sulfate (5%), and ammonium molybdate (1000ppm) to achieve synergistic effects of organic fertilization, inorganic salt regulation, and micronutrient enhancement.

[0045] 2. Synergistic function of components: Superphosphate has the functions of supplying phosphorus source and replacing calcium and sodium, ferrous sulfate simultaneously lowers pH and supplements iron, and ammonium molybdate precisely matches the nitrogen fixation needs of soybeans. The functions of each component are complementary and without redundancy.

[0046] 3. Dosage threshold control: Determine the optimal addition range of 0.2%-0.6% to avoid the risk of high dose (≥1.5%) salt stress, while taking into account soybean emergence rate, biomass and soil improvement effect.

[0047] 4. Optimized preparation process: The process of "raw material pretreatment - dry mixing + wet mixing two-step mixing - 55~60℃ medium temperature fermentation - 3 times turning" is adopted to ensure the uniformity of the conditioner and the effectiveness of nutrients.

[0048] 5. Differentiated application methods: Graded application plans are formulated for light, medium and severe saline-alkali soils. For severe saline-alkali soils, a two-step method of "short-term high-dose sodium reduction + long-term low-dose maintenance" is adopted, along with deep plowing and salt leaching measures.

[0049] 6. Precise supply of trace elements: Targeted addition of ammonium molybdate and ferrous sulfate to simultaneously increase the available molybdenum and iron content in the soil, meeting the needs of soybean nitrogenase synthesis and chlorophyll production.

[0050] 7. Synergistic effect of organic and inorganic: The humus of well-rotted cow manure chelates elements such as calcium, iron, and molybdenum, reducing nutrient precipitation. Combined with the physicochemical regulation of superphosphate and ferrous sulfate, it enhances the soil improvement and nutrient supply effects. Attached Figure Description

[0051] Figure 1 This is a process flow diagram (I) of the present invention;

[0052] Figure 2This is the process flow diagram (II) of the present invention;

[0053] Figure 3 This is a flowchart (I) of the application of the present invention;

[0054] Figure 4 This is the application flowchart (II) of the present invention;

[0055] Figure 5 This is the application flowchart (III) of the present invention. Detailed Implementation

[0056] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0057] Example 1: Formulation Design of Saline-Alkali Soil Conditioner

[0058] This conditioner uses a synergistic formula of "organic matrix + inorganic salt regulation + micronutrient enhancement", with each component composed of a specific mass percentage and precise ratio, as follows:

[0059]

[0060] Key features of the formula: The components work synergistically. The humus from well-rotted cow manure can chelate elements such as calcium, iron, and molybdenum, reducing nutrient precipitation and improving effectiveness. The Ca²⁺ of superphosphate and the acidic effect of ferrous sulfate form a dual-drive of "alkali reduction-sodium reduction". Ammonium molybdate precisely matches the nitrogen fixation needs of soybeans, avoiding redundancy or deficiency of trace elements.

[0061] Example 2: Conditioner Preparation Process

[0062] Raw material pretreatment: Controlling the moisture content of well-rotted cow manure is crucial. Too high a moisture content can lead to anaerobic fermentation and putrefaction, while too low a moisture content results in insufficient microbial activity. Applying ammonium molybdate after dissolving it can prevent uneven dispersion of solid particles and improve the uniformity of trace element distribution.

[0063] Medium-temperature fermentation: The temperature range of 55~60℃ can promote the reproduction of beneficial microorganisms, decompose the insoluble organic matter in the decomposed cow manure, and kill pathogens and weed seeds at the same time; turning the pile can ensure the air permeability of the pile and avoid the generation of local anaerobic environments.

[0064] Quality control: pH, total salt and nutrient indicators at the fermentation endpoint to ensure the stability of the conditioner's function.

[0065] Example 3: Application method of the conditioning agent

[0066] This method is applicable to coastal saline-alkali land and similar saline-alkali soils with pH 8.0~9.5, exchangeable sodium content <8%, and electrical conductivity 400~500us / cm. Its core application is soil improvement before soybean planting.

[0067] As attached Figure 1 and 2 As shown, the preparation process of the conditioner includes four core stages:

[0068] 1. Raw material pretreatment stage: This stage includes four parallel processes, which specifically treat the decomposed cow manure, superphosphate, ferrous sulfate, and ammonium molybdate to improve the uniformity of the raw materials and the subsequent mixing effect. The decomposed cow manure is pulverized through a 20-mesh sieve to ensure the dispersibility of the organic matrix; the ammonium molybdate is dissolved in an aqueous solution to prevent the solid ammonium molybdate from agglomerating during mixing.

[0069] 2. Precise mixing stage: First, dry mix the solid raw materials for 5-8 minutes, then spray with ammonium molybdate aqueous solution and wet mix for 10 minutes. The two-step mixing process ensures that there is no stratification or local enrichment of each component.

[0070] 3. Mesophilic fermentation and maturation stage: The height of the pile, the fermentation temperature, the number of times the pile is turned and the time are all key parameters. The range of each parameter is clearly marked in the attached diagram. The fermentation process achieves a balance between heat preservation and air permeability through a breathable membrane. The turning process is indicated by arrows indicating the interval time.

[0071] 4. Post-processing stage: Crushing and sieving, quality inspection, packaging and storage are carried out in sequence. The inspection stage is a quality control point. Unqualified products need to be returned to the fermentation stage for reprocessing.

[0072] As attached Figures 3 to 5 As shown, the core operational logic of field application embodies a closed loop of "soil testing - precise application - mixing - supporting management":

[0073] 1. Soil pretreatment stage: First, clean the land and then test the indicators. The test results directly determine the application rate (the test results and different application rates are connected by branch arrows in the attached diagram) to ensure the application is targeted.

[0074] 2. Application rate: There are three application schemes based on the degree of salinization. For mild to moderate saline-alkali soil, apply directly according to the recommended dosage. For severe saline-alkali soil, use the "two-step method". The attached diagram clearly indicates the addition ratio and supporting measures (deep plowing and salt leaching) for each scheme.

[0075] 3. Rotary tillage and mixing stage: The rotary tillage depth (15~20cm) is marked, and the requirement of "uniform contact" is explained in the text annotation to avoid the risk of excessive local concentration.

[0076] 4. Supporting management stage: The parameters for water supply and spraying during the flowering period (30mm water, 0.1% ammonium molybdate solution) are clearly marked to reflect the synergistic effect with the conditioner.

[0077] Example 4, Principle Explanation

[0078] 1. Principles of Soil Structure Improvement

[0079] The organic matter in well-rotted cow manure forms humus after fermentation. Humus molecules can combine with soil particles to form aggregates, reducing soil bulk density (bulk density decreases by 2.7% at a 3% addition). At the same time, the porous nature of humus improves soil field water holding capacity and permeability, solving the problems of soil compaction and poor water permeability in saline-alkali soil.

[0080] 2. Principle of Alkalinity and Sodium Reduction

[0081] Ferrous sulfate releases H⁺ upon dissolution, directly neutralizing soil alkalinity; the phosphate ions generated from the dissolution of superphosphate combine with Ca²⁺ and Na⁺ in the soil, indirectly weakening alkalinity. Simultaneously, the Ca²⁺ charge state (+2) provided by superphosphate is higher than that of Na⁺ (+1), making it more easily adsorbed by soil colloids, displacing soluble Na⁺, which is then removed through irrigation leaching, reducing soil sodium toxicity (exchangeable sodium is significantly reduced at a 1.5% addition level).

[0082] 3. Nutrient Supply Principle

[0083] Well-rotted cow manure provides organic matter and natural nitrogen and potassium nutrients, while superphosphate provides an efficient phosphorus source. The three work together to meet the macronutrient requirements of soybean growth. Ferrous sulfate and ammonium molybdate precisely supplement the trace elements iron and molybdenum. Among them, molybdenum, as the core component of soybean root nodule nitrogenase, can enhance biological nitrogen fixation capacity, while iron participates in chlorophyll synthesis and improves photosynthetic efficiency (soybean nitrogen, phosphorus, and potassium contents increase by 40%, 55%, and 32%, respectively, and molybdenum and iron contents increase by 3 times and 2.2 times, respectively).

[0084] 4. Salt stress avoidance principle

[0085] By controlling the amount of conditioner added within the range of 0.2% to 0.6%, the total amount of soluble salts (superphosphate, ferrous sulfate) introduced by the conditioner is ensured to be within the tolerance range of soybeans. At the same time, irrigation is carried out after application to reduce salt accumulation. For high salinity and alkalinity land, a "two-step method" is adopted: a high dose is used in the early stage to reduce sodium, and then a low dose is used to maintain the condition. This solves the salinity and alkalinity problem and avoids salt stress (the emergence rate reaches 56.4% to 76.9% and the biomass increases by 35% at an addition of 0.2% to 0.6%).

[0086] Example 5, Explanation of Action Relationships

[0087] In the preparation process, the effect of raw material pretreatment directly affects the uniformity of mixing: if the well-rotted cow manure is not crushed to below 20 mesh, it will lead to local enrichment of organic matrix after mixing; if ammonium molybdate is added directly without being dissolved, it will cause uneven distribution of trace elements, affecting subsequent fermentation and product function.

[0088] The temperature and turning action during the fermentation stage are related: when the temperature is below 55℃, the microbial activity is insufficient, and the fermentation time needs to be extended; if the pile is not turned in time, it will lead to local anaerobic conditions in the pile, produce a putrid smell, and reduce product quality.

[0089] During application, the application rate is linked to the degree of soil salinization and water management: the higher the degree of salinization, the higher the initial application rate can be, but more irrigation is required to leach salt; if the application rate is too high and the water is insufficient, it will lead to excessive local salt concentration and inhibit soybean germination.

[0090] Adapting conditioners to the soybean growth cycle: Apply conditioners 1-2 weeks before sowing to ensure they are fully dissolved and react with the soil, providing a suitable rhizosphere environment for seed germination and seedling growth; foliar spraying of ammonium molybdate during flowering complements the molybdenum supply from the conditioners in the soil, enhancing nitrogen fixation requirements during flowering.

[0091] Example 6: Verification of Technical Effects

[0092] Soil improvement effect: After applying 0.2%~0.6% conditioner, the soil pH dropped to 7.0~7.7, organic matter increased by 1.6%~3.8%, available phosphorus increased by 5.7~18 times, exchangeable sodium content did not increase significantly, and field water holding capacity increased by 2%~3%, meeting the soil environmental requirements for soybean growth.

[0093] Soybean growth effects: At a concentration of 0.6%, the soybean emergence rate reached 76.9%, an increase of 22% compared to the control; at a concentration of 0.2%, the biomass was the highest, an increase of 35% compared to the control; the content of nitrogen, phosphorus, potassium, iron, and molybdenum in soybeans was significantly increased, and nitrogen fixation capacity and photosynthetic efficiency were optimized.

[0094] Application safety: Within the recommended application rate range, there was no significant accumulation of total salt content in the soil and no salt stress symptoms were observed; the cation exchange capacity remained stable (12~13 cmol+ / kg), and the soil's nutrient retention capacity was not affected.

[0095] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A soil conditioner for saline-alkali soil suitable for soybean cultivation, characterized in that, It consists of the following components by mass percentage: 70% well-rotted cow manure 25% superphosphate 5% ferrous sulfate Ammonium molybdate 1000 ppm, based on the total mass of the conditioner.

2. The saline-alkali soil conditioner according to claim 1, characterized in that: The decomposed cow manure has a moisture content of ≤30% and is crushed and passed through a 20-mesh sieve. The superphosphate has an effective phosphorus content of ≥16% and is pulverized through a 40-mesh sieve. The ferrous sulfate mentioned is industrial grade ferrous sulfate heptahydrate.

3. The saline-alkali soil conditioner according to claim 1, characterized in that: The ammonium molybdate is first dissolved into a 5% aqueous solution before being mixed with other components.

4. A method for preparing the saline-alkali soil conditioner according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Raw material pretreatment: crush well-rotted cow manure through a 20-mesh sieve, and crush superphosphate and ferrous sulfate through a 40-mesh sieve respectively; (2) Dry mixing: Mix the pretreated solid raw materials in proportion and stir for 5-8 minutes; (3) Wet mixing: Add ammonium molybdate aqueous solution and continue stirring for 10 minutes; (4) Medium temperature fermentation: Ferment at 55-60℃ for 7-10 days, turning the pile once every 48 hours during the period; (5) Post-processing: The fermentation product is crushed and passed through a 30-mesh sieve. After passing the test, it is packaged.

5. The preparation method according to claim 4, characterized in that: In step (4), the height of the pile is controlled at 1.2-1.5m during fermentation and covered with a breathable film; The final fermentation pH is 6.5-7.0, and the total salt content is ≤3%.

6. A method for applying the saline-alkali soil conditioner according to any one of claims 1-3, characterized in that, include: (1) Soil testing: Determine the pH, electrical conductivity and exchangeable sodium content of the soil to be improved; (2) Differentiated application: Slightly saline-alkali soil with a pH of 8.0-8.5: Addition amount 0.2-0.3%; For moderately saline-alkali soil with a pH of 8.5-9.0: add 0.4-0.5%; For severely saline-alkali soil with pH > 9.0: apply 0.6% additive first, and then apply 0.2% maintenance amount 2 weeks later; (3) Rotary tillage and mixing: After application, rotary tillage to a depth of 15-20cm; (4) Water management: Irrigate with 30 mm of water within 24 hours after application.

7. The application method according to claim 6, characterized in that: Spray the leaves with a 0.1% ammonium molybdate solution during the soybean flowering period, at a rate of 20-30 L / mu.

8. The application method according to claim 6, characterized in that: The exchangeable sodium content of the slightly saline-alkali soil is <0.5 cmol+ / kg; The exchangeable sodium content of the severely saline-alkali soil is ≥0.8 cmol+ / kg.

9. A method for cultivating soybeans in saline-alkali land, characterized in that, include: Apply the soil conditioner according to any one of claims 6-8 15 days before sowing; Sow salt-tolerant soybean varieties at a density of 180,000-220,000 plants / hectare; Foliar application of molybdenum fertilizer during the flowering period.

10. The soybean cultivation method according to claim 9, characterized in that: The salt-tolerant soybean varieties mentioned are "Zhonghuang 301" or "Jidou 12".

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