Rice-green manure crop rotation fertilizing method capable of reducing phosphorus loss

Abstract

The invention discloses a rice-green manure crop rotation fertilizing method capable of reducing phosphorus loss and a special base fertilizer for green manure. The base fertilizer special for the green manure is prepared from ground phosphate rock, plant ash, straw powder, decomposed livestock manure, modified seaweed residues, borax, ammonium molybdate and a compound microbial agent according to a specific weight part ratio. The fertilizing method comprises the following steps: when the astragalus sinicus is sown in a green manure season, applying the special fertilizer, and moving 20-30% of the total amount of annual phosphate fertilizer forwards to the season; then performing field management and green manure turning and pressing; in the rice season, only 70%-80% of the residual phosphate fertilizer is applied, and the reduced nitrogen-potassium fertilizer is matched. According to the invention, through a'phosphate fertilizer forward-moving 'strategy, the difference between phosphorus conversion and loss laws of paddy and drought seasons is combined, phosphorus is activated and fixed by using crops in a green manure season, leaching loss of phosphorus in rice seasons is effectively reduced, green manure growth and nitrogen fixation fertilization are promoted at the same time, and cooperation of efficient utilization of phosphorus, stable yield and income increase of crops and environmental protection is realized.

Description

Technical Field

[0001] This invention belongs to the field of agricultural crop fertilization technology, specifically relating to a fertilization method for a rice-green manure rotation system and a special base fertilizer for green manure, particularly a fertilization method that optimizes the distribution of phosphate fertilizer throughout the year to reduce phosphorus loss and improve utilization efficiency. Background Technology

[0002] In nutrient management of green manure-rice rotation (such as milkvetch-rice rotation), there is a prominent contradiction between efficient phosphorus utilization and environmental protection. This system requires that phosphate fertilizer application strategies must simultaneously consider two distinctly different habitats: the flooded anaerobic environment of the rice season and the dry, aerobic environment of the green manure season. Phosphorus availability increases under flooded conditions during the rice season, but the risk of water loss and seepage from the field surface increases significantly, leading to low utilization rates and non-point source pollution. In contrast, during the green manure season (dry season), while the risk of phosphorus loss is lower, it is easily fixed in the soil and converted into insoluble forms, resulting in poor availability and difficulty in meeting the needs of rapid growth and nitrogen fixation of green manure crops (such as milkvetch).

[0003] Existing phosphate fertilizer application techniques have significant limitations: the conventional approach is to concentrate phosphate fertilizer application during the rice season, which can meet the rice's phosphorus requirements in the short term, but ignores the high loss of phosphorus under flooded conditions, resulting in wasted economic investment and environmental pressure. There are also attempts to increase phosphate fertilizer application during the green manure season to promote growth, but there is a lack of synergistic reduction plans with the rice season, and no specialized fertilizers have been developed for the nutrient requirements of green manure, often leading to phosphate fertilizer being fixed in the soil during the dry season. Furthermore, existing green manure cultivation techniques mostly focus on agronomic operations such as sowing and tilling, failing to systematically couple the core nutrient management strategy of "proactive phosphate fertilizer application" with specific functional base fertilizers (such as integrating growth-promoting microbial agents, soil phosphorus-activating components, and organic waste resources).

[0004] Currently available commercially available ordinary phosphate fertilizers or compound fertilizers cannot solve the above problems: water-soluble phosphate fertilizers (such as superphosphate) are easily lost during the rice season and easily fixed during the green manure season; while calcium magnesium phosphate fertilizers are more expensive than phosphate rock powder. At the same time, existing technologies pay little attention to the high-value utilization of agricultural organic waste (such as straw and seaweed residue) in green manure fertilizers, and have failed to achieve the synergy between nutrient cycling and soil improvement. Summary of the Invention

[0005] To address the aforementioned problems, this invention discloses a rice-green manure rotation fertilization method to reduce phosphorus loss. Its core lies in utilizing the synergistic effect mechanism between green manure crops and low-grade phosphorus sources. By shifting a portion of the total annual phosphate fertilizer application to the green manure season and applying a specialized functional base fertilizer, the root system of milkvetch is stimulated to secrete organic acids, thereby activating phosphate rock powder and soil-fixed phosphorus. This promotes growth through phosphorus and nitrogen fixation through growth, ultimately returning a large amount of nutrients to the soil through green manure incorporation. This closed-loop strategy of 'activation-fixation-return' achieves the efficient transfer and circulation of phosphorus from a 'potential pool' to an 'effective pool' within the rotation system, simultaneously achieving multiple goals: improving phosphorus utilization, ensuring crop yield, reducing environmental risks, and promoting the resource utilization of waste.

[0006] To achieve the above objectives, the present invention includes the following technical solutions.

[0007] This invention discloses a base fertilizer specifically for green manure, which is composed of the following raw materials in parts by weight: 15-25 parts of phosphate rock powder; 20-30 parts of wood ash; 10-20 parts straw powder 30-40 parts of well-rotted poultry and livestock manure; 5-10 parts of modified seaweed residue; Borax 0.5–1.0 parts; Ammonium molybdate 0.1–0.3 parts; 1-2 parts of compound microbial inoculant; The straw powder is made from rice, wheat, or corn straw that has been crushed to a particle size of ≤5 mm. The modified seaweed residue is prepared by modifying seaweed residue with organic acids; The compound microbial agent is composed of *Hua Gui Zhong Lao Ren Niu Bacterium*. Mesorhizobium huakuii and Bacillus mucilaginosus Bacillus mucilaginosus It is formulated with a live bacteria ratio of 1:1 to 1:2, and the total live bacteria count is ≥5.0×10⁻⁶. 9 CFU / g. Further, the modified seaweed residue in the above-mentioned green manure-specific base fertilizer is prepared as follows: seaweed residue is soaked in a 0.5%–1.0% citric acid solution at a mass ratio of 1:3–1:5 at 50–60°C for 2–3 hours, filtered, dried at 80–90°C until the moisture content is ≤12%, and then pulverized and passed through a 100-mesh sieve.

[0008] This invention also discloses a method for preparing the above-mentioned green manure-specific base fertilizer, comprising the following steps: (1) Raw material pretreatment: The modified seaweed residue prepared by the method described in claim 2 is mixed with phosphate rock powder, wood ash, straw powder and well-rotted poultry and livestock manure in proportion, and placed in a mixer and stirred at a speed of 20-30 rpm for 10-15 minutes to form a uniform base material; (2) Addition of trace elements: Dissolve borax and ammonium molybdate in water at a ratio of 10% to 20% of their total weight, and then add them evenly to the base material in step (1) by spraying while stirring. (3) Mixing of microbial agents: Mix the compound microbial agent with the material obtained in step (2) at room temperature (25±5℃), adjust the speed of the mixer to 15~20 rpm, mix for 5~8 minutes, and control the moisture content of the mixed material to ≤15%; (4) Granulation and packaging: The product of step (3) is fed into a disc granulator, a suitable amount of water mist is sprayed in, the particle size of the material is controlled at 2-4 mm, and after granulation, it is dried at a low temperature of ≤50℃ until the moisture content is ≤10%, and then sealed and packaged after cooling.

[0009] Furthermore, the above-mentioned method for reducing phosphorus loss through rice-purple clover rotation fertilization is characterized by including the application of the green manure-specific base fertilizer as described in claim 1 or 2, and includes the following steps: (1) Green manure sowing and base fertilizer application: After rice harvest or when rice panicles are drooping, sow purple clover at a rate of 22.5-37.5 kg / ha and apply the green manure base fertilizer at a rate of 1500-3000 kg / ha; (2) Field management: After sowing, promptly open ditches for drainage, with a depth of 20-25 cm and a width of 10-15 cm, to ensure that the field surface is continuously flooded for no more than 24 hours; leave rice straw with a high stubble of 30-40 cm and crush it before spreading it evenly. (3) Green manure incorporation: 7 to 15 days before the subsequent rice transplanting, turn the milkvetch into the soil to a depth of 10 to 15 cm and the amount of incorporation is 15 to 30 t / hectare; (4) Rice season fertilization: When transplanting rice, fertilizer management should be carried out on the basis of reducing chemical fertilizer application by 20% to 30%, including: Rice-specific base fertilizer: Apply rice-specific base fertilizer on the day of transplanting. It is a mixture of nitrogen, phosphorus, and potassium compound fertilizer and green manure-specific base fertilizer of claim 1 or 2 at a weight ratio of (3~5):1. The phosphorus content, calculated as P2O5, accounts for 70% to 80% of the total annual phosphorus fertilizer. Rice tillering fertilizer: 7-10 days after rice transplanting, apply 45-75 kg / ha of urea or other nitrogen fertilizer of equal nitrogen content; Rice panicle fertilizer: At the early stage of rice panicle differentiation, apply 30-60 kg / ha of urea (pure nitrogen) and 30-45 kg / ha of potassium chloride (potassium oxide).

[0010] The modified seaweed residue described in this invention not only serves as an organic carrier, but more importantly, it utilizes the natural bioactive substances it contains to stimulate the development of milkvetch roots and enhance its cold and drought resistance during the overwintering period, thereby ensuring the accumulation of biomass. At the same time, its colloidal properties help improve the soil aggregate structure and, together with phosphate rock powder and functional bacterial agents, construct a rhizosphere microecological environment conducive to nutrient activation and preservation.

[0011] Furthermore, in the above method, in step (1), the milkvetch seeds are treated with the compound microbial agent before sowing, and the amount of agent used is 1% to 3% of the seed weight.

[0012] Furthermore, in the above method, in step (2), if there is a continuous drought in winter, it is necessary to irrigate the soil until it is moist to combat the drought.

[0013] Furthermore, in the above method, in step (3), if the field surface is dry when plowing, plowing is carried out by dry plowing followed by irrigation or wet plowing.

[0014] Furthermore, in the above method, in step (4), if a single-element phosphate fertilizer is selected as the phosphorus source for rice-specific base fertilizer, monoammonium phosphate or diammonium phosphate is selected.

[0015] Furthermore, in the above method, in step (4), the total nitrogen input of the rice-specific base fertilizer, rice tillering fertilizer, and rice panicle fertilizer is calculated based on pure nitrogen, and their application ratio follows: single-season rice is applied at a ratio of 6:2:2; double-season rice is applied at a ratio of 7:0:3 for early rice and 5:3:2 for late rice.

[0016] This invention also discloses the application of the above-mentioned green manure-specific base fertilizer in increasing milk vetch biomass, promoting root nodule nitrogen fixation, or reducing phosphorus leaching loss in rice-milk vetch rotation systems.

[0017] Compared with existing technologies, this invention has the following outstanding beneficial effects: This invention discloses a rice-green manure rotation fertilization method to reduce phosphorus loss. 1. By scientifically shifting phosphate fertilizer application to the green manure season, it effectively utilizes the characteristic of less phosphorus loss during the dry season, avoiding the large-scale loss of phosphorus under flooded conditions during the rice season, thus reducing the risk of non-point source pollution from the source. 2. The dedicated green manure base fertilizer formula integrates organic and inorganic materials with specific functional microbial agents, which not only meets the nutrient requirements for the growth of milkvetch and significantly improves its biomass and nitrogen fixation capacity, but also helps to activate the original insoluble phosphorus in the soil and improve the soil micro-ecological environment. 3. Seaweed residue, as a by-product of the seaweed industry, is rich in seaweed polysaccharides, betaine, natural growth regulators, and various trace elements. It is not only an organic resource, but also has unique biostimulant functions, such as promoting seed germination, stimulating root development, and enhancing the crop's resistance to cold and drought. Although it is widely used in cash crops, this invention innovatively applies it to green manure production systems. The aim is to indirectly benefit the main rice crop by activating the growth potential of green manure crops, thereby reducing costs throughout the entire lifecycle and achieving high-value utilization of agricultural waste. 4. This invention significantly reduces phosphate fertilizer input during the rice season while ensuring that rice yields are not reduced, improving year-round phosphate fertilizer utilization efficiency and lowering production costs. Finally, this method makes extensive use of resources such as phosphate rock powder, straw, and seaweed residue, achieving high-value utilization of agricultural waste, which aligns with the development direction of green agriculture. Attached Figure Description

[0018] Figure 1 Effects of different treatments on growth and nitrogen fixation capacity of milkvetch (fresh grass yield (kg / ha)). Figure 2 Effects of different treatments on the growth and nitrogen fixation capacity of root nodules in milkvetch (fresh weight of root nodules (mg / plant)). Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Table 1 Raw Material List Example 1 A special base fertilizer for green manure used in rice-milk clover rotation is made from the following raw materials in parts by weight: 15 parts phosphate rock powder, 20 parts wood ash, 10 parts rice straw powder, 30 parts decomposed chicken manure, 5 parts modified seaweed residue, 0.5 parts borax, 0.1 parts ammonium molybdate, and 1 part compound microbial agent; The compound microbial agent is composed of *Hua Gui Zhong Lao Ren Xi Bacterium* (… Mesorhizobium huakuii ) and Bacillus mucilaginosus ( Bacillus mucilaginosus It is formulated with a live bacteria ratio of 1:1, and the total live bacteria count is 5.0 × 10⁻⁶. 9 CFU / g.

[0021] The modified seaweed residue is prepared by soaking the seaweed residue in a 0.5% citric acid solution at a mass ratio of 1:3 at 50°C for 3 hours, filtering, drying at 80°C until the moisture content is 12%, and then crushing and passing it through a 100-mesh sieve.

[0022] The preparation method of the above-mentioned green manure-specific base fertilizer is as follows: (1) The modified seaweed residue prepared by the above method is mixed with phosphate rock powder, wood ash, rice straw powder and decomposed chicken manure in proportion, and placed in a mixer and stirred at 20 rpm for 15 minutes to form a uniform base material. (2) Dissolve borax and ammonium molybdate in water at 10% of their total weight, and then add them evenly to the base material in step (1) by spraying while stirring. (3) Mix the compound microbial agent with the material obtained in step (2) at room temperature (20°C), with the mixer speed at 15 rpm and the mixing time at 8 minutes, and control the moisture content of the mixed material to be 15%; (4) The product from step (3) is fed into a disc granulator for granulation. The particle size is controlled at 2 mm. The product is dried at a low temperature of 50°C until the moisture content is 10%. After cooling, it is sealed and packaged.

[0023] Example 2 A special base fertilizer for green manure used in rice-milk clover rotation is made from the following raw materials in parts by weight: 20 parts phosphate rock powder, 25 parts wood ash, 15 parts wheat straw powder, 35 parts decomposed pig manure, 7.5 parts modified seaweed residue, 0.75 parts borax, 0.2 parts ammonium molybdate, and 1.5 parts compound microbial agent; The compound microbial agent is composed of *Hypertropha glomerata* and *Bacillus mucilaginosa* at a live bacteria ratio of 1:1.5, with a total live bacteria count of 7.5 × 10⁻⁶. 9 CFU / g.

[0024] The modified seaweed residue is prepared by soaking the seaweed residue in a 0.75% citric acid solution at a mass ratio of 1:4 at 55°C for 2.5 hours, filtering, drying at 85°C until the moisture content is 10%, and then crushing and passing it through a 100-mesh sieve.

[0025] The preparation method of the above-mentioned green manure-specific base fertilizer is as follows: (1) The modified seaweed residue prepared by the above method is mixed with phosphate rock powder, wood ash, wheat straw powder and decomposed pig manure in proportion, and placed in a mixer and stirred at 25 rpm for 12 minutes to form a uniform base material; (2) Dissolve borax and ammonium molybdate in water at 15% of their total weight, and then add them evenly to the base material in step (1) by spraying while stirring. (3) Mix the compound microbial agent with the material obtained in step (2) at room temperature (25°C), with the mixer speed at 18 rpm and the mixing time at 6 minutes, and control the moisture content of the mixed material to be 12%; (4) The product from step (3) is fed into a disc granulator for granulation. The particle size is controlled at 3 mm. The product is dried at a low temperature of 48°C until the moisture content is 8%. After cooling, it is sealed and packaged.

[0026] Example 3 A special base fertilizer for green manure used in rice-milk clover rotation is made from the following raw materials in parts by weight: 25 parts phosphate rock powder, 30 parts wood ash, 20 parts corn stalk powder, 40 parts well-rotted cow manure, 10 parts modified seaweed residue, 1.0 part borax, 0.3 parts ammonium molybdate, and 2 parts compound microbial inoculant. The compound microbial agent is composed of *Hypertropha chinensis* and *Bacillus mucilaginosus* at a live bacteria ratio of 1:2, with a total live bacteria count of 1.0 × 10⁻⁶. 10 CFU / g.

[0027] The modified seaweed residue is prepared by soaking the seaweed residue in a 1.0% citric acid solution at a mass ratio of 1:5 at 60°C for 2 hours, filtering, drying at 90°C until the moisture content is 8%, and then crushing and passing it through a 100-mesh sieve.

[0028] The preparation method of the above-mentioned green manure-specific base fertilizer is as follows: (1) The modified seaweed residue prepared by the above method is mixed with phosphate rock powder, wood ash, corn stalk powder and well-rotted cow manure in proportion, and placed in a mixer and stirred at 30 rpm for 10 minutes to form a uniform base material. (2) Dissolve borax and ammonium molybdate in water at 20% of their total weight, and then add them evenly to the base material in step (1) by spraying while stirring. (3) Mix the compound microbial agent with the material obtained in step (2) at room temperature (30°C), with the mixer speed at 20 rpm and the mixing time at 5 minutes, and control the moisture content of the mixed material to be 10%; (4) The product from step (3) is fed into a disc granulator for granulation. The particle size is controlled at 4 mm. The product is dried at a low temperature of 45°C until the moisture content is 7%. After cooling, it is sealed and packaged.

[0029] Comparative Example 1 A base fertilizer, made from the following raw materials in parts by weight: 20 parts phosphate rock powder, 25 parts wood ash, 15 parts wheat straw powder, 35 parts decomposed pig manure, 0.75 parts borax, 0.2 parts ammonium molybdate, and 1.5 parts compound microbial agent (excluding modified seaweed residue).

[0030] The compound microbial agent is the same as in Example 2.

[0031] The remaining preparation methods are the same as in Example 2.

[0032] Comparative Example 2 A base fertilizer, made from the following raw materials in parts by weight: 20 parts phosphate rock powder, 25 parts wood ash, 15 parts wheat straw powder, 35 parts decomposed pig manure, 7.5 parts modified seaweed residue, 0.75 parts borax, and 0.2 parts ammonium molybdate; (excluding compound microbial inoculants).

[0033] The preparation method of the modified seaweed residue is the same as in Example 2.

[0034] The remaining preparation methods are the same as in Example 2.

[0035] Comparative Example 3 A base fertilizer, made from the following raw materials in parts by weight: 20 parts phosphate rock powder, 25 parts wood ash, 15 parts wheat straw powder, 35 parts decomposed pig manure, 7.5 parts modified seaweed residue, and 1.5 parts compound microbial agent (excluding borax and ammonium molybdate).

[0036] The preparation method of the modified seaweed residue is the same as in Example 2. The composite microbial agent is the same as in Example 2.

[0037] The remaining preparation methods are the same as in Example 2.

[0038] Comparative Example 4 A base fertilizer, made from the following raw materials in parts by weight: 20 parts phosphate rock powder, 25 parts wood ash, 35 parts decomposed pig manure, 7.5 parts modified seaweed residue, 0.75 parts borax, 0.2 parts ammonium molybdate, and 1.5 parts compound microbial agent (excluding straw powder).

[0039] The preparation method of the modified seaweed residue is the same as in Example 2. The composite microbial agent is the same as in Example 2.

[0040] The remaining preparation methods are the same as in Example 2.

[0041] Test Example 1 Experiment on the effects of milkvetch biomass and nitrogen fixation capacity of root nodules Objective: To verify the promoting effect of the green manure-specific base fertilizer of the present invention on the growth and nitrogen fixation capacity of milkvetch.

[0042] method: A pot experiment was conducted using typical paddy soil from southern China. Seven treatments were established: Examples 1-3 and Comparative Examples 1-4, with six replicates for each treatment. Milk vetch was sown in early October, and the appropriate fertilizer was applied as a basal fertilizer at a rate of 1500 kg / ha. During the peak flowering period of milk vetch (late April of the following year), the aboveground fresh weight, dry weight, number of root nodules, and fresh weight of root nodules were measured for each treatment.

[0043] The results are shown in Table 2 and... Figure 1 and Figure 2 .

[0044] Table 2 Effects of different treatments on the growth and nitrogen fixation capacity of *Astragalus membranaceus* root nodules (Data has been rounded) Conclusion: Application of the complete green manure-specific base fertilizer of this invention (Examples 1-3) can significantly improve the biomass and nitrogen fixation capacity of milkvetch (Acer truncatum). Among them, Example 2 (median formulation) showed the best effect. The comparative examples lacking key components (such as microbial agents and modified seaweed residue) all showed varying degrees of decline in various indicators, indicating that there is a synergistic promoting effect among the components.

[0045] Test Example 2 Experiment on the effects of soil phosphorus activation and fixed phosphorus transformation Objective: To evaluate the effect of the method of the present invention on increasing the available phosphorus content in soil and activating insoluble phosphorus.

[0046] method: Soil samples from the 0–20 cm topsoil layer were collected after the milkvetch was plowed in and before rice transplanting for each treatment. The content of available phosphorus (Olsen-P) in the soil was determined. Simultaneously, the Zhang-Jackson continuous extraction method was used to determine the content of different forms of phosphorus in the soil, focusing on the conversion of easily fixed phosphorus such as aluminum-bound phosphorus (Al-P) and iron-bound phosphorus (Fe-P) into available phosphorus. Each treatment was measured six times.

[0047] The results are shown in Table 3.

[0048] Table 3. Effects of different treatments on soil phosphorus forms and availability (mg / kg) Conclusion: The treatment of this invention can significantly increase the available phosphorus content in the soil and promote the conversion of fixed phosphorus (Al-P, Fe-P), thereby increasing the phosphorus activation coefficient. The compound microbial inoculant (comparative example 2 missing) and the modified seaweed residue (comparative example 1 missing) play a key role in activating the soil phosphorus pool.

[0049] Test Example 3 Phosphorus leaching simulation test Objective: To verify the effectiveness of phosphate fertilizer application and reduction techniques in reducing phosphate leaching.

[0050] method: A soil column leaching apparatus was used to simulate phosphorus leaching under heavy rainfall or irrigation conditions during the rice growing season. Soil columns were filled with soil treated in each season (after incorporating milkvetch). Simulated water and fertilizer management during the rice growing season was implemented, with phosphate fertilizer applied as a basal agent at the recommended rate (70% of the total annual phosphate fertilizer). Leachate was collected from each treatment, and the total phosphorus concentration was measured to calculate the cumulative phosphorus leaching over the entire rice growing season. Each treatment was replicated six times.

[0051] The results are shown in Table 4.

[0052] Table 4 Comparison of cumulative phosphorus leaching under different treatments *Comparative Example 5: Conventional fertilization (100% phosphate fertilizer applied during the rice season, and no phosphate fertilizer applied during the green manure season) was introduced as a blank control in this test case.

[0053] Conclusion: The phosphate fertilizer pre-application and reduction technology of the present invention (Example 2) can significantly reduce the risk of leaching of quaternary phosphorus in rice. The leaching amount is reduced by more than 50% compared with conventional fertilization (Comparative Example 5), indicating that the present invention has significant environmental benefits in controlling agricultural non-point source pollution.

[0054] Test Example 4 Analysis of Rice Yield Composition and Partial Productivity of Phosphate Fertilizer Objective: To examine the effects of the fertilization method of the present invention on subsequent rice yield and phosphate fertilizer utilization efficiency.

[0055] method: Field plot trials were conducted. During the milkvetch season, fertilization and tilling were performed according to the treatments. During the rice season, a uniform reduction in phosphate fertilizer application (70% of the annual total) was applied according to the method described in this invention. After rice maturity, rice yield and its components (number of effective panicles, number of grains per panicle, and thousand-grain weight) were measured for each treatment. Partial phosphate productivity (PFP, unit: kg rice / kg P2O5) was calculated. Six plots were replicated for each treatment.

[0056] The results are shown in Table 5.

[0057] Table 5. Effects of different treatments on rice yield and partial productivity of phosphorus fertilizer. *Comparative Example 5: Conventional fertilization (100% phosphate fertilizer applied during the rice season), (data rounded off).

[0058] Conclusion: Under the condition of reducing phosphate fertilizer application by 30%, the rice yield of the treatments using the green manure-specific base fertilizer of this invention (Examples 1-3) was the same as or slightly higher than that of the conventional full-amount phosphate application treatment (Comparative Example 5), and the partial productivity (PFP) of phosphate fertilizer was significantly increased by more than 40%. This indicates that the present invention achieves efficient utilization of phosphate fertilizer and achieves the goal of reducing fertilizer use, stabilizing yield, and even increasing yield.

[0059] Test Example 5 Soil microbial community and enzyme activity response Objective: To investigate the effects of the fertilization method of this invention on soil microbial characteristics and the activity of key phosphorus invertases.

[0060] method: Soil samples were collected during the peak tillering stage of rice. Soil microbial biomass carbon (MBC) and microbial biomass phosphorus (MBP) were measured. Simultaneously, soil enzyme activities related to phosphorus cycling, including alkaline phosphatase (ALP) and phytase activities, were measured. Each indicator was measured six times.

[0061] The results are shown in Table 6.

[0062] Table 6. Effects of different treatments on soil microbial characteristics and phosphorus invertase activity Conclusion: The treatment of this invention can significantly increase soil microbial biomass and enzyme activity related to phosphorus activation. The addition of compound microbial agents (this effect was not present in Comparative Example 2) plays a key role in improving the soil micro-ecological environment and driving soil phosphorus transformation.

[0063] Test Example 6 Annual phosphorus balance and economic benefit analysis Objective: To evaluate the annual phosphorus revenue and expenditure and economic benefits under the technical model of this invention.

[0064] method: The apparent annual phosphorus utilization rate ((phosphorus uptake by milkvetch + phosphorus uptake by rice) / total phosphate fertilizer input × 100%) and phosphorus surplus (phosphate fertilizer input - crop uptake - leaching) were calculated by measuring the phosphorus uptake of milkvetch, rice uptake, and phosphorus leaching (refer to test example 3). Simultaneously, fertilizer costs and output value for each treatment were statistically analyzed, and net profit was calculated. Calculations were based on data from six replicate plots.

[0065] The results are shown in Table 7.

[0066] Table 7. Annual phosphorus balance and economic benefits analysis for different treatments *Comparative Example 5: Conventional Fertilization Conclusion: The technology of this invention (Example 2) significantly improves the apparent utilization rate of phosphorus throughout the year, reduces soil phosphorus surplus, and mitigates environmental risks. Simultaneously, due to the reduction in phosphate fertilizer use and the increased yield of milkvetch promoting rice growth, cost savings and increased income are achieved, with net benefits superior to conventional fertilization methods, demonstrating good economic and environmental benefits.

[0067] Test Case Summary Through the above series of test examples, the present invention demonstrates significant effects. In terms of agronomic effects, the yield of fresh milkvetch using the special base fertilizer of the present invention (Example 2) reached 31,200 kg / ha, an increase of 31.1% compared to Comparative Example 2 which lacked the inoculant, and the number of root nodules increased by 48.6%. In terms of environmental effects, the phosphorus leaching loss in the treatment of the present invention (Example 2) was only 0.85 kgP2O5 / ha, a decrease of 52.3% compared to conventional fertilization (Comparative Example 5). Regarding soil ecology, the available phosphorus content in the soil treated in Example 2 reached 31.2 mg / kg, the microbial biomass carbon was 410 mg / kg, and the alkaline phosphatase activity was 198 μmol / g / d, all significantly better than the comparative examples. In terms of economic yield, the rice yield using the method of the present invention was 7,820 kg / ha, and the partial productivity of phosphorus fertilizer (PFP) reached 111.7 kg / kg, an increase of 45.1% compared to conventional fertilization. The annual apparent phosphorus utilization rate increased to 42.5%, achieving cost reduction and increased income. Data shows that this invention has successfully achieved multiple goals: weight loss, stable production, fattening, and emission reduction.

[0068] The above are merely a few preferred embodiments of the present invention, described in a relatively specific and detailed manner, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A special base fertilizer for green manure, characterized in that, consists of the following raw materials by weight: Phosphate rock 15-25 parts; Wood ash 20-30 parts; Straw powder 10-20 parts, Decomposed poultry manure 30-40 parts; Modified seaweed residue 5-10 parts; Borax 0.5-1.0 parts; Ammonium molybdate 0.1-0.3 parts; Compound microbial inoculant 1-2 parts; The straw powder is made of rice, wheat or corn straw which is crushed to a particle size of ≤5 mm; The modified seaweed residue is seaweed residue which is modified by a citric acid solution; The complex microbial agent is compounded by Bradyrhizobium sp. GWRC Mesorhizobium huakuii and Bacillus mucilaginosus Bacillus mucilaginosus in a ratio of 1:1-1:2 in terms of viable bacteria, and the total viable bacteria are ≥5.0×10 9 CFU / g.

2. The base fertilizer for green manure special use according to claim 1, characterized in that, The preparation method of the modified seaweed residue is as follows: the seaweed residue is soaked in a citric acid solution with a concentration of 0.5%-1.0% at 50-60°C for 2-3 hours at a mass ratio of 1:3-1:5, filtered, dried at 80-90°C until the moisture content is ≤12%, and then crushed to pass through a 100-mesh sieve.

3. A method for preparing the green manure special base fertilizer according to claim 1 or 2, characterized in that, comprising the following steps: (1) Raw material pretreatment: the modified seaweed residue prepared by the method of claim 2 is mixed with phosphate rock, wood ash, straw powder and decomposed poultry manure in proportion, placed in a mixer and stirred at a speed of 20-30 rpm for 10-15 minutes to form a uniform base material; (2) Trace element addition: borax and ammonium molybdate are dissolved in water accounting for 10%-20% of their total weight, and then added uniformly to the base material of step (1) in a spraying manner under stirring; (3) Inoculant mixing: the compound microbial inoculant is mixed with the material obtained in step (2) at room temperature (25±5°C), the speed of the mixer is adjusted to 15-20 rpm, and the mixing time is 5-8 minutes, and the moisture content of the mixed material is controlled to be ≤15%; (4) Granulation and packaging: the product of step (3) is sent into a disc granulator, an appropriate amount of water mist is sprayed, and the particle size of the material is controlled to be 2-4 mm, then the granulated material is dried at a low temperature of ≤50°C until the moisture content is ≤10%, and then sealed and packaged after cooling.

4. A method of reducing phosphorus loss in a rice-miscanthus crop rotation fertilization method, characterized by, The green manure is Chinese milk vetch, which comprises applying the green manure special base fertilizer of claim 1 or 2, and comprises the following steps: (1) Green manure sowing and base fertilizer application: Chinese milk vetch is sown in a cover crop at the time of rice harvesting or when the rice ear is hooked, the sowing amount is 22.5-37.5 kg / ha, and the green manure special base fertilizer is applied, the application amount is 1500-3000 kg / ha; (2) Field management: after sowing, the ditch is opened in time to drain water, the ditch depth is 20-25 cm, the ditch width is 10-15 cm, and the continuous water accumulation on the field surface is ensured to be not more than 24 hours; the rice straw is left with a stubble height of 30-40 cm and crushed and uniformly scattered; (3) Green manure incorporation: 7-15 days before the subsequent rice transplanting, the Chinese milk vetch is incorporated into the soil, the incorporation depth is 10-15 cm, and the incorporation amount is 15-30 t / ha; (4) Rice season fertilization: at the time of rice transplanting, the fertilizer is managed on the basis of reducing the application of chemical fertilizer by 20%-30%, which comprises: The rice special base fertilizer is prepared by compounding the nitrogen-phosphorus-potassium compound fertilizer and the green manure special base fertilizer of the green manure special base fertilizer according to a weight ratio of 3-5:1, wherein the phosphorus is 70%-80% of the total amount of phosphorus fertilizer in a year. The rice tillering fertilizer is 45-75 kg / ha of urea or other nitrogen fertilizer with equal nitrogen content, which is applied 7-10 days after the rice is transplanted. The rice ear fertilizer is 30-60 kg / ha of urea and 30-45 kg / ha of potassium chloride, which is applied at the early stage of young ear differentiation.

5. The method of claim 4, wherein, In step (1), the Astragalus sinicus seeds are treated by seed dressing with the compound microbial agent before sowing, and the amount of the microbial agent is 1%-3% of the weight of the seeds.

6. The method of claim 4, wherein, In step (2), if continuous drought occurs in winter, the soil is irrigated to be wet to resist drought.

7. The method of claim 4, wherein, In step (3), if the field is dry when it is turned over, the field is turned over after being irrigated or wet ploughed.

8. The method of claim 4, wherein, In step (4), if the single-element phosphorus fertilizer is used as the phosphorus source of the rice special base fertilizer, the monoammonium phosphate or diammonium phosphate is selected.

9. The method of claim 4, wherein, In step (4), the total amount of nitrogen in the rice special base fertilizer, the rice tillering fertilizer and the rice ear fertilizer is 6:2:2 for single-cropping rice, 7:0:3 for early rice of double-cropping rice and 5:3:2 for late rice.

10. The green manure special base fertilizer of claim 1 or 2 is used for increasing the biomass of Astragalus sinicus, promoting nodule nitrogen fixation or reducing the loss of phosphorus leaching in the rice-Astragalus sinicus rotation system.

Images