A method for reducing fertilizer and increasing yield by using straw returning to field

Abstract

The application discloses a method for reducing fertilizer and increasing yield by returning straw to field, and belongs to the technical field of biomass resource utilization. The method for reducing fertilizer and increasing yield by returning straw to field comprises the following steps: in the autumn of the first year, spraying the epipremnum aureum solution on the crop straw, spraying the microbial growth promoter after natural standing, spraying the compound microorganism after air-drying, ploughing into the soil, irrigating, and planting crops in the spring of the second year. The method can reduce the fertilizer consumption while improving the yield of crops, and achieves the effect of reducing fertilizer and increasing yield.

Description

Technical Field

[0001] This invention relates to the field of biomass resource utilization technology, and in particular to a method for reducing fertilizer use and increasing yield by returning straw to the field. Background Technology

[0002] Straw is a major byproduct of agriculture and also an important renewable organic resource, containing abundant nutrients such as carbon, nitrogen, phosphorus, potassium, and trace elements. In recent years, with the progress of the times and social development, the rational utilization of straw resources has received increasing attention. On the one hand, as a traditional energy material, straw is gradually being replaced by energy sources such as petroleum and natural gas; on the other hand, crop yields are constantly increasing, resulting in more and more surplus straw.

[0003] Returning straw to the field increases soil organic matter, improves soil structure, loosens the soil, increases porosity, reduces bulk density, and promotes microbial activity and crop root development. Currently, straw return methods are mainly divided into direct and indirect return. Indirect return requires more labor and presents certain technical challenges. Therefore, direct straw return is currently the main measure for dealing with surplus straw. However, direct straw return has problems such as slow decomposition and maturation, leading to increased diseases in subsequent crops. Summary of the Invention

[0004] The purpose of this invention is to provide a method for reducing fertilizer use and increasing yield by returning straw to the field, so as to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] One of the technical solutions of the present invention: a method for reducing fertilizer and increasing yield by returning straw to the field, comprising the following steps:

[0007] In the first autumn, spray purslane solution on the crop straw, let it stand naturally, then spray with a microbial growth promoter, let it dry, then spray with compound microorganisms, plow it into the soil, irrigate, and plant crops in the second spring.

[0008] Furthermore, the method for preparing the purslane solution includes the following steps:

[0009] Fresh purslane and water are mixed, crushed, and then filtered to obtain the purslane solution.

[0010] Furthermore, the mass ratio of the fresh purslane to water is 1:(8-10).

[0011] The oxalic acid in purslane solution can break down the dense, rigid structure of straw fibers, promoting subsequent decomposition of the straw.

[0012] Furthermore, the length of the straw is 2-3 cm;

[0013] The natural settling time is 25 to 30 days.

[0014] Furthermore, the microbial growth promoter comprises the following raw materials in parts by weight: 40-50 parts starch fermentation product, 6-8 parts sunflower seeds, and 2-3 parts soybeans.

[0015] The citric acid contained in starch fermentation products can provide carbon and energy sources for microorganisms, promoting their growth and reproduction. At the same time, citric acid can regulate soil pH, making the soil environment suitable for microbial growth and reproduction.

[0016] Pantothenic acid, found in sunflower seeds and soybeans, can enhance the metabolic capacity of microorganisms, promote the decomposition of straw, and generate beneficial substances (antibiotics, cell wall degrading enzymes, chitinase, etc.).

[0017] Furthermore, the method for preparing the starch fermentation product includes the following steps:

[0018] Starch and water are mixed, liquefying enzyme is added, and after liquefaction, the mixture is filtered to obtain the supernatant.

[0019] Soybean meal powder was added to the supernatant, mixed evenly, sterilized, inoculated with Aspergillus niger, and fermented to obtain the starch ferment.

[0020] Furthermore, the mass ratio of starch to water is 1:(4-5);

[0021] The liquefaction temperature is 90–95°C, and the time is 90–120 min;

[0022] The mass ratio of the supernatant to soybean meal powder is 100:(0.7-0.8);

[0023] The effective viable count of the *Aspergillus niger* strain is 1.0–5.0 × 10⁻⁶. 6 cfu / mL;

[0024] The volume ratio of the supernatant to Aspergillus niger is 100:(3.5-4.5).

[0025] The fermentation culture was carried out at a temperature of 35–37°C for 24–36 hours.

[0026] Furthermore, the dosage of the microbial growth promoter is 1.0–1.5 kg / mu.

[0027] Furthermore, the composite microorganism comprises the following components in parts by volume: 5-8 parts of Bacillus belye, 3-4 parts of Azotobacter chrysogenum, 5-7 parts of Bacillus subtilis, 4-5 parts of Lactobacillus plantarum, 3-4 parts of Trichoderma reesei, 1-2 parts of Protozoa chrysospora, and 4-6 parts of Trichoderma harzianum.

[0028] Furthermore, the dosage of the compound microorganisms is 0.8–1.0 kg / mu.

[0029] Bacillus berberis and Azotobacter spp. can increase the nitrogen content in the soil, regulate the carbon-nitrogen ratio, accelerate the rapid decomposition of straw, and at the same time promote crop growth and increase crop yield.

[0030] Bacillus subtilis can secrete antibiotics, cell wall degrading enzymes, chitinases, and other substances that inhibit the germination of pathogenic spores and the growth of mycelia.

[0031] Trichoderma harzianum has a strong ability to adapt to the environment and reproduces rapidly. It can quickly occupy the living space and material resources near the plant roots, forming a protective shield and blocking the opportunity for pathogens to infect the plant. Furthermore, it can attach to pathogens, secrete extracellular enzymes, dissolve the cell walls of pathogens, penetrate hyphae, absorb nutrients, and thus kill the pathogens.

[0032] The synergistic effect of Bacillus subtilis and Trichoderma harzianum can not only inhibit the germination of pathogenic spores and mycelial growth, but also kill pathogens, thus playing a better role in the prevention and control of diseases.

[0033] The synergistic effect of Lactobacillus plantarum, Trichoderma reesei, and Protozoa chrysophagus can promote straw decomposition and increase the rate of straw decay, thus solving the problem of slow straw decomposition and maturation when straw is directly returned to the field.

[0034] The present invention discloses the following technical effects:

[0035] The method of this invention can effectively solve the problem that direct straw return to the field results in slow straw decomposition and maturation, increased disease in subsequent crops, and consequently reduced yields in subsequent crops.

[0036] The method of this invention can increase crop yield while reducing fertilizer usage, achieving the effect of reducing fertilizer use and increasing yield. Detailed Implementation

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0040] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0041] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0042] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0043] After crops mature, the valuable fruit parts are harvested, while the remaining discarded branches and stalks are generally called straw. Straw primarily contains large amounts of cellulose and lignin. As a byproduct of agriculture, it not only contains essential nutrients for plant growth such as nitrogen, phosphorus, and potassium, but also some trace elements. However, while agriculture has rapidly developed, improving rural development and changing lifestyles, the yield of crop straw has increased year after year, but its uses have gradually decreased. Its use as livestock feed and domestic fuel has begun to decline. With the gradual abandonment of straw energy and the shift in supply methods, straw has become stagnant and discarded, even leading to regional, seasonal, and structural surpluses. Most farmers no longer recycle straw, choosing instead to burn or discard it after harvest. However, the large-scale burning of straw is not only a waste of resources, but also causes severe pollution to the living environment. The large amount of ash produced by burning is seriously harmful to people's respiratory system. More importantly, such burning destroys a large amount of soil nutrients, and the storage of organic carbon also decreases sharply, severely disrupting the balance of the land ecosystem. Therefore, how to effectively utilize straw and reduce resource waste and environmental pollution is a question worthy of in-depth exploration.

[0044] With advancements in science and technology, some countries place great emphasis on combining soil conservation with soil improvement, employing straw return technology to enhance soil fertility and considering it a fundamental measure for improving soil moisture. The main source of nutrients in farmland is chemical fertilizer, which lacks organic matter, easily leading to soil compaction and moisture deterioration. Straw, on the other hand, is a natural organic fertilizer that can reduce the amount of chemical fertilizer used, provide a favorable growing environment for crops, promote the internal cycle of the farmland ecosystem, and form a stable ecosystem.

[0045] Currently, straw return to the field is mainly divided into direct return and indirect return.

[0046] Direct straw return to the field involves directly returning straw to the soil, or processing it by crushing it before burying it in the soil. Therefore, there are basically two methods of direct straw return: straw burial and straw mulching. Straw burial involves using a straw shredder to crush the straw into uniform segments of about 10cm in size after the autumn harvest, spreading them on the soil surface, and then burying them in the soil using agricultural machinery. This method is very convenient, but requires a high degree of precision from the agricultural machinery. This method ensures that all the nutrients in the straw are returned to the soil and accelerates the decomposition of the straw, further enriching the soil with organic matter, improving the soil's physical and chemical properties, and significantly enhancing its fertility. However, it also has limitations; straw burial is geographically restricted and requires a high degree of mechanization. Straw mulching is a conservation tillage system. The process involves crushing the straw and evenly covering it on the soil surface or retaining 30% of the straw height. This method requires no complicated steps and is easy to operate. This method of returning soil to the field helps maintain soil temperature, reduces direct sunlight, and minimizes soil moisture loss, providing excellent soil conditions for crop growth and development, and promoting and regulating above-ground growth. This method is suitable for arid and semi-arid regions, as the increased soil moisture content enhances the crop's drought resistance. Its disadvantages include the potential for weeds and pests to affect crop emergence.

[0047] Indirect straw return to the field mainly takes two forms: composting and returning straw to the field after it has been fed to livestock. Composting involves piling up straw, which gradually decomposes under high temperatures. Through effective microbial decomposition, it produces abundant nutrients that promote growth. After thorough decomposition, the straw is then effectively returned to the soil as needed. This composting method typically takes place in pre-designated pits or in livestock pens. To further facilitate decomposition, a suitable amount of decomposing agent is added to the pit, which is then covered with plastic film and finally sealed with soil. Research indicates that the temperature during composting should be controlled at around 50℃, and the corresponding humidity ideally around 70%. This method makes more effective use of the fertilizer resources in straw, solves the problem of slow straw decomposition to a certain extent, allows nutrients to be supplied to the soil more quickly, retains rich organic matter, reduces the consumption and loss of nitrogen in straw, and increases potassium in the soil, which greatly promotes the improvement of soil physical and chemical properties. However, the construction of composting sites requires strong government support, large agricultural machinery for straw collection, a large amount of labor, and certain technical difficulties.

[0048] The practice of returning straw to the field after it has been ingested by livestock (pigs, cattle, horses) primarily utilizes the role of straw as feed. After digestion, the protein, cellulose, and other nutrients in the straw are absorbed and utilized by the animals. The resulting excrement becomes environmentally friendly organic fertilizer, which is applied to the fields, increasing soil organic matter and thus enhancing soil fertility. This method is widely considered the best ecological and environmentally friendly practice, and is highly scientific and green. However, in actual production, this method requires a supporting system, which somewhat affects its promotion and feasibility.

[0049] Currently, the main method of returning straw to the field is direct return, which is simple to operate, cost-effective, efficient, and easy to promote. This method is also the most rational and effective way to utilize straw resources in the future.

[0050] However, straw is difficult to decompose naturally. In some northern regions, the temperature during the corn harvest season is generally between 10 and 15°C, making straw decomposition even more difficult. This results in a long decomposition and transformation cycle of corn straw in the soil after it is returned to the field, making it difficult to use as a fertilizer source for the next crop. In addition, long-term straw return to the field aggravates the occurrence of root diseases in subsequent crops.

[0051] In the specific embodiments of this invention, the Bacillus bellis, Azotobacter chrysogenum, Bacillus subtilis, Lactobacillus plantarum, Trichoderma reesei, Protozoa chrysospora, Trichoderma harzianum, Bacillus thuringiensis, Trichoderma viride, and Aspergillus niger were all purchased from the China Industrial Microbial Culture Collection Center.

[0052] Among them, the product number of Bacillus belyssus is: CICC 22619;

[0053] Product code for Azotobacter brownii: CICC 22661;

[0054] Product code for Bacillus subtilis: CICC 10732;

[0055] Product code for Lactobacillus plantarum: CICC 2028;

[0056] Product code for Trichoderma reesei: CICC 41494;

[0057] Product code for *Phanerochaete chrysosporium*: CICC 41781;

[0058] Trichoderma harzianum product code: CICC 13056;

[0059] Product code for Bacillus thuringiensis: CICC 20558;

[0060] Product code for *Trichoderma viride*: CICC 40492;

[0061] Product code for Aspergillus niger: CICC 40300.

[0062] The preparation methods of Bacillus belye, Azotobacter chrysogenum, Bacillus subtilis, Lactobacillus plantarum, Trichoderma reesei, Phanerochaete chrysosporium, Trichoderma harzianum, Bacillus thuringiensis, Trichoderma viride, and Aspergillus niger used in specific embodiments of the present invention are as follows:

[0063] (1) *Bacillus belye*, *Azotobacter chrysogenum*, *Bacillus subtilis*, *Lactobacillus plantarum*, *Trichoderma reesei*, *Phanerochaete chrysosporium*, *Trichoderma harzianum*, *Bacillus thuringiensis*, and *Trichoderma viride* were inoculated into liquid culture medium, activated, and then fermented. The effective viable counts were 3.0 × 10⁻⁶. 8 CFU / mL of Bacillus belye, Azotobacter chrysogenum, Bacillus subtilis, Lactobacillus plantarum, Trichoderma reesei, Phanerochaete chrysosporium, Trichoderma harzianum, Bacillus thuringiensis, and Trichoderma viride.

[0064] (2) After activating and culturing Aspergillus niger in liquid culture medium, fermentation culture was carried out to obtain an effective viable count of 1.0–5.0 × 10⁻⁶. 6 / mL of Aspergillus niger solution.

[0065] The liquid culture medium consisted of 5.0 g / L peptone, 3.0 g / L beef extract, and 5.0 g / L sodium chloride, with a pH of 7.0; it was then sterilized by moist heat for 20 minutes.

[0066] The experimental site in the specific embodiment of the present invention is a crop planting field in Shenyang City, Liaoning Province.

[0067] The field was divided into several plots, each plot being 300m. 2 Each embodiment or comparative example processes 3 cells, and all cells are randomly distributed.

[0068] The corn variety planted is Shendan 10.

[0069] Example 1

[0070] A method to reduce fertilizer and increase yield by returning straw to the field:

[0071] (1) After the corn harvest in early October of the first year, the corn stalks are crushed to a length of 2-3 cm, and then purslane solution is sprayed on the stalks at a rate of 50 kg / mu. The stalks are left to stand naturally for 30 days.

[0072] Preparation method of purslane solution: Mix fresh purslane and water in a mass ratio of 1:9, crush with a grinder and filter through 8 layers of gauze to obtain purslane solution.

[0073] (2) Spray a solution of microbial growth promoter (made by mixing microbial growth promoter with water, with a water consumption of 40 kg per mu) onto the straw after treatment in step (1). The amount of microbial growth promoter used is 1.2 kg / mu.

[0074] The microbial growth promoter is composed of the following raw materials in parts by weight: 45 parts starch fermentation product, 8 parts sunflower seed powder (500 mesh) and 2 parts soybean powder (500 mesh).

[0075] Preparation method of starch fermentation product:

[0076] a. Mix starch and water at a mass ratio of 1:4 to obtain starch slurry. Add liquefying enzyme (α-amylase, 1000 U / L, volume ratio of starch slurry to liquefying enzyme is 100:0.1) to the starch slurry, liquefy (liquefaction temperature is 90℃, time is 90 min), and then filter to obtain supernatant.

[0077] b. Add soybean meal powder to the supernatant (supernatant to soybean meal powder mass ratio of 100:0.8), mix well, and sterilize (moist heat sterilization, 120℃, 20min). Inoculate with Aspergillus niger (effective viable count of 3.0 × 10⁻⁶). 6 / mL, the volume ratio of supernatant to Aspergillus niger is 100:4.0), fermented (fermentation temperature is 37℃, time is 24h) to obtain starch fermentation product.

[0078] (3) After the microbial growth promoter solution sprayed in step (2) has dried, spray the compound microbial solution (made by mixing compound microorganisms with water, using 40 kg of water per acre), with a compound microbial dosage of 1.0 kg / acre. After drying, plow the mixture into the soil (30 cm deep) and irrigate with 50 m³ of water. 3 / mu.

[0079] The complex microorganism consists of the following components in parts by volume: 6 parts of Bacillus belye bacterial suspension, 4 parts of Azotobacter chrysogenum bacterial suspension, 7 parts of Bacillus subtilis bacterial suspension, 4 parts of Lactobacillus plantarum bacterial suspension, 4 parts of Trichoderma reesei bacterial suspension, 2 parts of Phanerochaete chrysosporium bacterial suspension, and 5 parts of Trichoderma harzianum bacterial suspension.

[0080] (4) Corn is planted in early April of the second year. Before planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as base fertilizer at a rate of 5.04 kg / mu (based on pure nitrogen). Phosphorus fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is also applied as base fertilizer. Then, corn is planted flat at a density of 4000 plants / mu.

[0081] Apply nitrogen fertilizer (urea containing 46.0% pure nitrogen) at the corn tasseling stage and the grain-filling stage, with application rates of 8.4 kg / mu (based on pure nitrogen) and 3.36 kg / mu (based on pure nitrogen), respectively.

[0082] The recommended nitrogen application rate for corn throughout its entire growth period is 16.8 kg / mu, and the recommended phosphorus application rate is 8.4 kg / mu.

[0083] (5) Carry out routine field management, without applying other fertilizers during the period, and harvest corn in early October, and count and calculate corn yield.

[0084] Example 2

[0085] A method to reduce fertilizer and increase yield by returning straw to the field:

[0086] (1) After the corn harvest in early October of the first year, the corn stalks are crushed to a length of 2-3 cm, and then purslane solution is sprayed on the stalks at a rate of 50 kg / mu. The stalks are left to stand naturally for 25 days.

[0087] Preparation method of purslane solution: Mix fresh purslane and water at a mass ratio of 1:10, crush with a grinder and filter with 8 layers of gauze to obtain purslane solution.

[0088] (2) Spray a solution of microbial growth promoter (made by mixing microbial growth promoter with water, with a water consumption of 40 kg per mu) onto the straw after treatment in step (1). The amount of microbial growth promoter used is 1.5 kg / mu.

[0089] The microbial growth promoter is composed of the following raw materials in parts by weight: 40 parts starch fermentation product, 6 parts sunflower seed powder (500 mesh) and 3 parts soybean powder (500 mesh).

[0090] Preparation method of starch fermentation product:

[0091] a. Mix starch and water at a mass ratio of 1:4.5 to obtain starch slurry. Add liquefying enzyme (α-amylase, 1000 U / L, volume ratio of starch slurry to liquefying enzyme is 100:0.1) to the starch slurry, liquefy (liquefaction temperature is 95℃, time is 120 min), and then filter to obtain supernatant.

[0092] b. Add soybean meal powder to the supernatant (supernatant to soybean meal powder mass ratio of 100:0.8), mix well, and sterilize (moist heat sterilization, 120℃, 20min). Inoculate with Aspergillus niger (effective viable count of 5.0 × 10⁻⁶). 6 / mL, the volume ratio of supernatant to Aspergillus niger is 100:3.5), fermented (fermentation temperature is 35℃, time is 36h) to obtain starch fermentation product.

[0093] (3) After the microbial growth promoter solution sprayed in step (2) has dried, spray the compound microbial solution (made by mixing compound microorganisms with water, using 40 kg of water per acre), with a compound microbial dosage of 0.8 kg / acre. After drying, plow the mixture into the soil (30 cm deep) and irrigate with 50 m³ of water. 3 / mu.

[0094] The compound microorganism consists of the following components in parts by volume: 5 parts of Bacillus belye bacterial suspension, 3 parts of Azotobacter chrysogenum bacterial suspension, 5 parts of Bacillus subtilis bacterial suspension, 5 parts of Lactobacillus plantarum bacterial suspension, 4 parts of Trichoderma reesei bacterial suspension, 2 parts of Phanerochaete chrysosporium bacterial suspension, and 4 parts of Trichoderma harzianum bacterial suspension.

[0095] (4) Corn is planted in early April of the second year. Before planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as base fertilizer at a rate of 5.04 kg / mu (based on pure nitrogen). Phosphorus fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is also applied as base fertilizer. Then, corn is planted flat at a density of 4000 plants / mu.

[0096] Apply nitrogen fertilizer (urea containing 46.0% pure nitrogen) at the corn tasseling stage and the grain-filling stage, with application rates of 8.4 kg / mu (based on pure nitrogen) and 3.36 kg / mu (based on pure nitrogen), respectively.

[0097] The recommended nitrogen application rate for corn throughout its entire growth period is 16.8 kg / mu, and the recommended phosphorus application rate is 8.4 kg / mu.

[0098] (5) Carry out routine field management, without applying other fertilizers during the period, and harvest corn in early October, and count and calculate corn yield.

[0099] Example 3

[0100] A method to reduce fertilizer and increase yield by returning straw to the field:

[0101] (1) After the corn harvest in early October of the first year, the corn stalks are crushed to a length of 2-3 cm, and then purslane solution is sprayed on the stalks at a rate of 50 kg / mu. The stalks are left to stand naturally for 30 days.

[0102] Preparation method of purslane solution: Mix fresh purslane and water in a mass ratio of 1:8, crush with a grinder and filter with 8 layers of gauze to obtain purslane solution.

[0103] (2) Spray a solution of microbial growth promoter (made by mixing microbial growth promoter with water, with a water consumption of 40 kg per mu) onto the straw after treatment in step (1). The amount of microbial growth promoter used is 1.0 kg / mu.

[0104] The microbial growth promoter is composed of the following raw materials in parts by weight: 50 parts starch fermentation product, 7 parts sunflower seed powder (500 mesh) and 2 parts soybean powder (500 mesh).

[0105] Preparation method of starch fermentation product:

[0106] a. Mix starch and water at a mass ratio of 1:5 to obtain starch slurry. Add liquefying enzyme (α-amylase, 1000 U / L, volume ratio of starch slurry to liquefying enzyme is 100:0.1) to the starch slurry, liquefy (liquefaction temperature is 90℃, time is 120 min), and then filter to obtain supernatant.

[0107] b. Add soybean meal powder to the supernatant (supernatant to soybean meal powder mass ratio of 100:0.7), mix well, and sterilize (moist heat sterilization, 120℃, 20min). Inoculate with Aspergillus niger (effective viable count of 1.0×10⁻⁶). 6 / mL, the volume ratio of supernatant to Aspergillus niger is 100:4.5), fermented (fermentation temperature is 37℃, time is 36h) to obtain starch fermentation product.

[0108] (3) After the microbial growth promoter solution sprayed in step (2) has dried, spray the compound microbial solution (made by mixing compound microorganisms with water, using 40 kg of water per acre), with a compound microbial dosage of 1.0 kg / acre. After drying, plow the mixture into the soil (30 cm deep) and irrigate with 50 m³ of water. 3 / mu.

[0109] The complex microorganism consists of the following components in parts by volume: 8 parts of Bacillus belye bacterial suspension, 3 parts of Azotobacter chrysogenum bacterial suspension, 7 parts of Bacillus subtilis bacterial suspension, 4 parts of Lactobacillus plantarum bacterial suspension, 3 parts of Trichoderma reesei bacterial suspension, 1 part of Phanerochaete chrysosporium bacterial suspension, and 6 parts of Trichoderma harzianum bacterial suspension.

[0110] (4) Corn is planted in early April of the second year. Before planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as base fertilizer at a rate of 5.04 kg / mu (based on pure nitrogen). Phosphorus fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is also applied as base fertilizer. Then, corn is planted flat at a density of 4000 plants / mu.

[0111] Apply nitrogen fertilizer (urea containing 46.0% pure nitrogen) at the corn tasseling stage and the grain-filling stage, with application rates of 8.4 kg / mu (based on pure nitrogen) and 3.36 kg / mu (based on pure nitrogen), respectively.

[0112] The recommended nitrogen application rate for corn throughout its entire growth period is 16.8 kg / mu, and the recommended phosphorus application rate is 8.4 kg / mu.

[0113] (5) Carry out routine field management, without applying other fertilizers during the period, and harvest corn in early October, and count and calculate corn yield.

[0114] Comparative Example 1

[0115] A corn planting method:

[0116] (1) After the corn is harvested in early October of the first year, clean up the corn stalks.

[0117] (2) Corn is planted in early April of the second year. Before planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as base fertilizer at a rate of 7.2 kg / mu (based on pure nitrogen). Phosphorus fertilizer (pure phosphorus P2O5, 12 kg / mu) is also applied as base fertilizer. Then, corn is planted flat at a density of 4000 plants / mu.

[0118] Apply nitrogen fertilizer (urea containing 46.0% pure nitrogen) at the corn tasseling stage and the grain-filling stage, with application rates of 12 kg / mu (based on pure nitrogen) and 4.8 kg / mu (based on pure nitrogen), respectively.

[0119] The recommended nitrogen application rate for corn throughout its entire growth period is 24 kg / mu, and the recommended phosphorus application rate is 12 kg / mu.

[0120] (3) Carry out routine field management, without applying other fertilizers during the period, and harvest corn in early October, and count and calculate corn yield.

[0121] Comparative Example 2

[0122] A method to reduce fertilizer and increase yield by returning straw to the field:

[0123] (1) After the corn harvest in early October of the first year, the corn stalks are shredded to a length of 2-3 cm, plowed into the soil (30 cm), and irrigated with 50 m³ of water. 3 / mu.

[0124] (2) Corn is planted in early April of the second year. Before planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as base fertilizer at a rate of 5.04 kg / mu (based on pure nitrogen). Phosphorus fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is also applied as base fertilizer. Then, corn is planted flat at a density of 4000 plants / mu.

[0125] Apply nitrogen fertilizer (urea containing 46.0% pure nitrogen) at the corn tasseling stage and the grain-filling stage, with application rates of 8.4 kg / mu (based on pure nitrogen) and 3.36 kg / mu (based on pure nitrogen), respectively.

[0126] The recommended nitrogen application rate for corn throughout its entire growth period is 16.8 kg / mu, and the recommended phosphorus application rate is 8.4 kg / mu.

[0127] (3) Carry out routine field management, without applying other fertilizers during the period, and harvest corn in early October, and count and calculate corn yield.

[0128] Comparative Example 3

[0129] Same as Example 1, except that the Bacillus subtilis culture was replaced with an equal volume of Bacillus thuringiensis culture, and the Trichoderma harzianum culture was replaced with an equal volume of Trichoderma viride culture.

[0130] Comparative Example 4

[0131] Same as Example 1, except that the composite microorganism does not contain Bacillus bellis bacterial solution and Azotobacter chrysogenum bacterial solution.

[0132] Comparative Example 5

[0133] Same as Example 1, except that purslane solution was not sprayed on the straw.

[0134] Comparative Example 6

[0135] Same as Example 1, except that the starch fermentation product is replaced with citric acid and water in a mass ratio of 1:4.

[0136] Comparative Example 7

[0137] Same as Example 1, except that the sunflower seed powder and soybean powder in the microbial growth promoter are replaced with an equal mass of glucose.

[0138] The yields of the examples and comparative maize (yields were measured when the moisture content was around 13%) are shown in Table 1.

[0139] Table 1. Maize Yield

[0140]

[0141]

[0142] As can be seen from Table 1, the method of the present invention can increase corn yield while reducing fertilizer use by 30%.

[0143] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for reducing fertilizer use and increasing yield by returning straw to the field, characterized in that, Includes the following steps: In the first autumn, spray purslane solution on crop straw, let it stand naturally, then spray microbial growth promoter, let it dry, then spray compound microorganisms, plow it into the soil, irrigate, and plant crops in the second spring. The preparation steps of the purslane solution include: mixing and crushing fresh purslane and water, then filtering to obtain the purslane solution; The microbial growth promoter comprises the following raw materials in parts by weight: 40-50 parts starch fermentation product, 6-8 parts sunflower seeds, and 2-3 parts soybeans; The preparation steps of the starch fermentation product include: mixing starch and water, adding liquefying enzyme, liquefying and filtering to obtain supernatant; adding soybean meal powder to the supernatant, mixing evenly and sterilizing, inoculating with Aspergillus niger, fermenting and culturing to obtain the starch fermentation product; The composite microorganism comprises the following components in parts by volume: 5-8 parts of Bacillus belye, 3-4 parts of Azotobacter chrysogenum, 5-7 parts of Bacillus subtilis, 4-5 parts of Lactobacillus plantarum, 3-4 parts of Trichoderma reesei, 1-2 parts of Protozoa chrysospora, and 4-6 parts of Trichoderma harzianum.

2. The method according to claim 1, characterized in that, The mass ratio of the fresh purslane to water is 1:(8~10).

3. The method according to claim 1, characterized in that, The length of the straw is 2-3 cm; And / or, the natural settling time is 25 to 30 days.

4. The method according to claim 1, characterized in that, The mass ratio of starch to water is 1:(4~5); And / or, the liquefaction temperature is 90~95℃ and the time is 90~120min; And / or, the mass ratio of the supernatant to soybean meal powder is 100:(0.7~0.8). And / or, the effective viable count of the *Aspergillus niger* is 1.0~5.0 × 10⁻⁶. 6 cfu / mL; And / or, the volume ratio of the supernatant to Aspergillus niger is 100:(3.5~4.5); And / or, the fermentation culture temperature is 35~37℃ and the time is 24~36h.

5. The method according to claim 1, characterized in that, The dosage of the microbial growth promoter is 1.0~1.5 kg / mu.

6. The method according to claim 1, characterized in that, The dosage of the compound microorganisms is 0.8~1.0 kg / mu.

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