Method for reducing weight and increasing yield by straw returning to field

Abstract

The invention discloses a method for reducing weight and increasing yield by using straw returning to field, and belongs to the technical field of biomass resource utilization. The method comprises the following steps: spraying a purslane solution on crop straws in autumn of the first year, spraying a microbial growth promoter after natural standing, spraying compound microorganisms after airing, ploughing and burying into soil, irrigating, and planting crops in spring of the second year. The method provided by the invention can increase the yield of crops while reducing the use amount of the chemical fertilizer, thereby achieving the effects of losing weight and increasing yield.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass resource utilization, and particularly to a method for reducing fertilizer application and increasing yield by returning straw to the field. Background Art

[0002] Straw is the main by-product of crops and an important renewable organic resource, containing abundant nutrients such as carbon, nitrogen, phosphorus, potassium and medium and trace elements. In recent years, with the progress of the times and social development, the rational utilization of straw resources has attracted more and more attention. On the one hand, as a traditional energy material, straw has gradually been replaced by energy substances such as petroleum and natural gas; on the other hand, the per-unit yield of crops is constantly increasing, resulting in more and more surplus straw.

[0003] Returning straw to the field can increase soil organic matter, improve soil structure, loosen the soil, increase porosity, reduce bulk density, and promote the activity of microorganisms and the development of crop roots. At present, the straw returning methods are mainly divided into direct straw returning and indirect straw returning. The indirect straw returning has a large amount of labor and certain technical difficulties. Therefore, direct straw returning is the main measure to solve the surplus straw at present, but there are problems such as slow decomposition and decay rate of straw in direct straw returning, which lead to the aggravation of diseases of subsequent crops. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for reducing fertilizer application and increasing yield by returning straw to the field to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above purpose, the present invention provides the following scheme:

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

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

[0008] Further, the preparation method of the purslane solution comprises the following steps:

[0009] Mix fresh purslane and water, crush and filter to obtain the purslane solution.

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

[0011] The oxalic acid contained in the purslane solution can destroy the dense rigid structure of straw fibers and promote the subsequent decomposition of straw.

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

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

[0014] Furthermore, the microbial growth promoter comprises raw materials in the following parts by mass: 40 to 50 parts of starch ferment, 6 to 8 parts of sunflower seeds, and 2 to 3 parts of soybeans.

[0015] The citric acid contained in the starch ferment can provide carbon source and energy for microorganisms, promote the growth and reproduction of microorganisms. At the same time, citric acid can adjust the soil pH value, making the soil environment suitable for the growth and reproduction of microorganisms.

[0016] The pantothenic acid contained in sunflower seeds and soybeans can enhance the metabolic capacity of microorganisms, promote the decomposition of straw and the production of beneficial substances (such as antibiotics, cell wall degrading enzymes, chitinase, etc.).

[0017] Furthermore, the preparation method of the starch ferment comprises the following steps:

[0018] Mix starch and water, then add liquefying enzyme, filter after liquefaction to obtain the supernatant;

[0019] Add soybean meal powder to the supernatant, mix evenly and sterilize, inoculate Aspergillus niger, and perform fermentation culture to obtain the starch ferment.

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

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

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

[0023] The effective viable count of the Aspergillus niger is 1.0 - 5.0×10 6 cfu / mL;

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

[0025] The temperature of the fermentation culture is 35 - 37 °C, and the time is 24 - 36 h.

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

[0027] Furthermore, the compound microorganism comprises the following components in parts by volume: 5 - 8 parts of Bacillus velezensis, 3 - 4 parts of Azotobacter chroococcum, 5 - 7 parts of Bacillus subtilis, 4 - 5 parts of Lactobacillus plantarum, 3 - 4 parts of Trichoderma reesei, 1 - 2 parts of Phanerochaete chrysosporium, and 4 - 6 parts of Trichoderma harzianum.

[0028] Furthermore, the dosage of the composite microorganism is 0.8 - 1.0 kg / mu.

[0029] Bacillus velezensis and Azotobacter chroococcum 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 substances such as antibiotics, cell wall degrading enzymes, and chitinase, inhibiting the spore germination and hyphal growth of pathogenic bacteria.

[0031] Trichoderma harzianum has strong environmental adaptability and fast reproduction speed. It can quickly occupy the living space and material resources near the plant roots, form a protective cover, block the opportunity for pathogenic bacteria to infect plants, and it can attach to pathogenic bacteria, secrete extracellular enzymes, dissolve the cell wall of pathogenic bacteria, penetrate hyphae, absorb nutrients, and then kill pathogenic bacteria.

[0032] The synergistic effect of Bacillus subtilis and Trichoderma harzianum can not only inhibit the spore germination and hyphal growth of pathogenic bacteria, but also kill pathogenic bacteria, thus playing a better role in preventing and controlling diseases.

[0033] The synergistic effect of Lactobacillus plantarum, Trichoderma reesei and Phanerochaete chrysosporium can promote straw decomposition, improve the decomposition speed of straw, and solve the problem of slow decomposition and composting speed of straw in direct straw returning to the field.

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

[0035] The method of the present invention can effectively solve the problems of slow decomposition and composting speed of straw in direct straw returning to the field, the aggravation of diseases of subsequent crops, and thus the reduction of the yield of subsequent crops.

[0036] The method of the present invention can increase the yield of crops while reducing the amount of chemical fertilizers used, achieving the effect of reducing fertilizer use and increasing production. Detailed Embodiments

[0037] The various exemplary embodiments of the present invention are now 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, characteristics, and implementation schemes of the present invention.

[0038] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0039] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0040] Without departing from the scope or spirit of the present invention, various modifications and variations can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0041] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0042] It should be noted that the aspects not detailed in the present invention are all conventional operating means in the art and are not the focus of the present invention.

[0043] After crops reach maturity, the valuable fruit parts are harvested, and the remaining useless branches are generally called straw, which mainly contains a large amount of cellulose and lignin. As a by-product of agricultural products, it not only contains essential nutrients such as nitrogen, phosphorus, and potassium for plant growth, but also contains some trace elements. However, while agriculture is developing rapidly, it has gradually improved rural development and changed the lifestyle, and at the same time, the output of crop straw has been increasing year by year, but its uses have gradually decreased, and its utilization methods such as being used as livestock feed and domestic fuel have begun to decline gradually. With the gradual abandonment of straw energy and the gradual change of the supply mode, it has caused the retention and abandonment of straw, and even regional, seasonal, and structural surpluses have occurred. Most farmers no longer recycle straw but choose to burn or discard the straw after harvest. However, burning a large area of straw is not only a waste of resources but also causes severe pollution to the living environment. The large amount of dust produced by burning is seriously harmful to people's respiratory systems, and most importantly, such burning destroys a large amount of nutrients in the soil, and the storage of organic carbon also drops sharply, seriously disrupting the balance of the land ecosystem. Therefore, how to effectively utilize straw, reduce resource waste and environmental pollution is a problem worthy of in-depth exploration.

[0044] With advances in science and technology, some countries are placing significant emphasis on integrating soil conservation with agricultural practices, employing straw return to enhance soil fertility as a fundamental measure to improve soil moisture. Farmland primarily relies on chemical fertilizers, which lack organic matter, leading to soil compaction and loss of moisture. Straw, a natural organic fertilizer, can reduce the need for chemical fertilizers, provide a favorable growing environment for crops, and promote internal circulation within farmland ecosystems, ultimately fostering a stable ecosystem.

[0045] At present, the methods of returning straw to the fields are mainly divided into direct return and indirect return.

[0046] Direct straw return to the field involves returning straw directly to the soil, or pulverizing it before burying it in the soil. There are two basic methods for direct straw return: straw burial and straw mulching. Straw burial involves using a straw chopper after the autumn harvest to shred the straw into uniformly sized segments of approximately 10 cm. These segments are then spread on the soil surface and then buried using agricultural machinery. This method is very convenient, but requires high precision from agricultural machinery. This method returns all the nutrients in the straw to the soil and significantly increases its decomposition rate, further enriching the soil with organic matter, improving its physical and chemical properties, and significantly enhancing its fertility. However, it also has certain limitations. Straw burial is subject to geographical restrictions and requires a high level of mechanization. Straw mulching is a conservation tillage system that involves pulverizing the straw and evenly covering the soil surface, or leaving 30% of the straw height. This method requires no complex steps and is easy to operate. This method of returning soil to the field maintains soil temperature, reduces direct sunlight, and minimizes soil moisture loss, providing excellent soil conditions for crop growth and development, promoting and regulating aboveground growth. This method is suitable for arid and semi-arid regions, where increased soil moisture enhances crop drought resistance. However, its disadvantage is that weeds and certain pests and diseases can affect crop emergence.

[0047] Indirect straw return to the field is mainly carried out in two ways: composting and returning to the field through the stomach. Composting is a method of returning straw to the field by piling it together. Under high temperature conditions, the straw will gradually begin to rot. Through the effective decomposition of microorganisms, it will produce rich nutrients that promote growth. After the straw is fully decomposed, it will be effectively returned to the soil as needed. Usually, this composting method is carried out in a planned composting pit or in the livestock pen of a farmer's home. In order to make the straw decompose more effectively, an appropriate amount of composting agent will be added to the composting pit, which will then be sealed with plastic film and then covered with soil. Relevant studies have shown that the temperature should be controlled at around 50°C during composting, and the corresponding humidity should be around 70%. This method makes more effective use of the fertilizer resources in straw, solves the problem of slow decomposition of straw to a certain extent, enables nutrients to be supplied to the soil more quickly, retains rich organic matter, reduces the consumption and loss of nitrogen in straw, and increases the potassium element in the soil, greatly promoting the improvement of soil physical and chemical properties. However, the construction of composting sites requires strong support from the government, and large-scale agricultural machinery is needed to collect straw. It requires a large amount of labor and has certain technical difficulties.

[0048] The "trans-stomach return to the field" method primarily utilizes straw as feed. After being ingested and digested by livestock (pigs, cattle, and horses), 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 enhancing soil fertility. This method is widely considered to be the best ecological and environmentally friendly practice, and is very scientific and green. In actual production, this method requires a supporting system of related systems, which has a certain impact on 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, effective, and easy to promote. This method is also a reasonable and effective way to utilize straw resources in the future.

[0050] However, straw is difficult to be micro-decomposed under natural conditions. During the corn harvest period in some northern regions, the temperature is generally between 10 and 15 degrees Celsius, making straw decomposition even more difficult. As a result, it takes a long time for corn straw to be decomposed and transformed in the soil after being returned to the field, making it difficult to serve 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] The Bacillus velezensis, Azotobacter chrysosporium, Bacillus subtilis, Lactobacillus plantarum, Trichoderma reesei, Phanerochaete chrysosporium, Trichoderma harzianum, Bacillus thuringiensis, Trichoderma viride and Aspergillus niger used in the specific embodiment of the present invention were all purchased from the China Industrial Microorganism Culture Collection Center.

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

[0053] The product number of Azotobacter chroococcum: CICC 22661;

[0054] The product number of Bacillus subtilis: CICC 10732;

[0055] The product number of Lactobacillus plantarum: CICC 2028;

[0056] The product number of Trichoderma reesei: CICC 41494;

[0057] The product number of Phanerochaete chrysosporium: CICC 41781;

[0058] The product number of Trichoderma harzianum: CICC 13056;

[0059] The product number of Bacillus thuringiensis: CICC 20558;

[0060] The product number of Trichoderma viride: CICC 40492;

[0061] The product number of Aspergillus niger: CICC 40300.

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

[0063] (1) Bacillus velezensis, Azotobacter chroococcum, Bacillus subtilis, Lactobacillus plantarum, Trichoderma reesei, Phanerochaete chrysosporium, Trichoderma harzianum, Bacillus thuringiensis and Trichoderma viride are respectively inoculated in a liquid medium for activation culture and then fermentation culture to obtain Bacillus velezensis bacterial liquid, Azotobacter chroococcum bacterial liquid, Bacillus subtilis bacterial liquid, Lactobacillus plantarum bacterial liquid, Trichoderma reesei bacterial liquid, Phanerochaete chrysosporium bacterial liquid, Trichoderma harzianum bacterial liquid, Bacillus thuringiensis bacterial liquid and Trichoderma viride bacterial liquid with effective viable counts of 3.0×10 8 cfu / mL.

[0064] (2) Aspergillus niger is inoculated in a liquid medium for activation culture and then fermentation culture to obtain Aspergillus niger bacterial liquid with an effective viable count of 1.0 - 5.0×10 6 / mL.

[0065] The components of the liquid medium: peptone 5.0 g / L, beef extract 3.0 g / L and sodium chloride 5.0 g / L, pH 7.0; autoclaved for 20 min.

[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 300m 2 ,Each embodiment or comparative example processes 3 cells, and all cells are randomly distributed.

[0068] The corn variety planted is Shendan No. 10.

[0069] Example 1

[0070] A method for reducing weight and increasing yield by returning straw to fields:

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

[0072] The preparation method of the purslane solution is as follows: fresh purslane and water are mixed in a mass ratio of 1:9, the mixture is crushed by a grinder, and then filtered through 8 layers of gauze to obtain the purslane solution.

[0073] (2) Spraying a solution of a microbial growth promoter (prepared by mixing the microbial growth promoter with water, with a water consumption of 40 kg per mu) on the straw treated in step (1), the amount of the microbial growth promoter used being 1.2 kg / mu.

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

[0075] Preparation method of starch fermentation product:

[0076] a. Starch and water were mixed in a mass ratio of 1:4 to obtain a starch slurry. A liquefying enzyme (α-amylase, 1000 U / L, a volume ratio of starch slurry to liquefying enzyme of 100:0.1) was added to the starch slurry, liquefied (liquefaction temperature was 90°C for 90 min) and filtered to obtain a supernatant.

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

[0078] (3) After the solution of the microbial growth promoter sprayed in step (2) is dried, the solution of the composite microorganism (made by mixing the composite microorganism with water, with a water consumption of 40 kg per mu) is sprayed. The amount of the composite microorganism is 1.0 kg / mu. After drying, the soil is plowed into the soil (30 cm) and irrigated. The irrigation water consumption is 50 m 3 / mu.

[0079] The composite microorganism is composed of the following components in parts by volume: 6 parts of Bacillus velezensis liquid, 4 parts of Azotobacter chrysosporium liquid, 7 parts of Bacillus subtilis liquid, 4 parts of Lactobacillus plantarum liquid, 4 parts of Trichoderma reesei liquid, 2 parts of Phanerochaete chrysosporium liquid and 5 parts of Trichoderma harzianum liquid.

[0080] (4) Corn was planted in early April of the second year. Nitrogen fertilizer (urea containing 46.0% pure nitrogen) was applied as base fertilizer before corn planting, with a dosage of 5.04 kg / mu (calculated as pure nitrogen), and phosphorus fertilizer (pure phosphorus P2O5, 8.4 kg / mu) was applied as base fertilizer. Then, corn was planted flat with a planting density of 4,000 plants / mu.

[0081] During the corn tasseling stage and the grain filling stage, nitrogen fertilizer (urea containing 46.0% pure nitrogen) was applied at a dosage of 8.4 kg / mu (calculated as pure nitrogen) and 3.36 kg / mu (calculated as pure nitrogen), respectively.

[0082] The nitrogen application rate during the entire growth period of corn planting is 16.8 kg / mu and the phosphorus application rate is 8.4 kg / mu.

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

[0084] Example 2

[0085] A method for reducing weight and increasing yield by returning straw to fields:

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

[0087] The preparation method of the purslane solution is as follows: fresh purslane and water are mixed in a mass ratio of 1:10, crushed with a grinder, and then filtered with 8 layers of gauze to obtain the purslane solution.

[0088] (2) Spraying a solution of a microbial growth promoter (prepared by mixing the microbial growth promoter with water, with a water consumption of 40 kg per mu) on the straw treated in step (1), the amount of the microbial growth promoter used being 1.5 kg / mu.

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

[0090] Preparation method of starch fermentate:

[0091] a. After mixing starch and water in a mass ratio of 1:4.5, a starch slurry is obtained. Liquefying enzyme (α-amylase, 1000 U / L, the volume ratio of the starch slurry to the liquefying enzyme is 100:0.1) is added to the starch slurry, and after liquefaction (the liquefaction temperature is 95 °C and the time is 120 min), filtration is carried out to obtain the supernatant;

[0092] t b. Soybean meal powder is added to the supernatant (the mass ratio of the supernatant to the soybean meal powder is 100:0.8), and after mixing evenly, sterilization is carried out (moist heat sterilization, 120 °C, 20 min), and Aspergillus niger is inoculated (the effective viable count is 5.0×10 6 / mL, the volume ratio of the supernatant to Aspergillus niger is 100:3.5), and fermentation culture is carried out (the fermentation culture temperature is 35 °C and the time is 36 h) to obtain the starch fermentate.

[0093] (3) After the solution of the microbial growth promoter sprayed in step (2) is dried, a solution of compound microorganisms (prepared by mixing compound microorganisms with water, the water consumption per mu is 40 kg) is sprayed. The dosage of the compound microorganisms is 0.8 kg / mu. After drying, it is plowed into the soil (30 cm), and irrigation is carried out. The irrigation water consumption is 50 m 3 / mu.

[0094] The compound microorganisms are composed of the following components in parts by volume: 5 parts of Bacillus velezensis bacterial liquid, 3 parts of Azotobacter chroococcum bacterial liquid, 5 parts of Bacillus subtilis bacterial liquid, 5 parts of Lactobacillus plantarum bacterial liquid, 4 parts of Trichoderma reesei bacterial liquid, 2 parts of Phanerochaete chrysosporium bacterial liquid, and 4 parts of Trichoderma harzianum bacterial liquid.

[0095] (4) Maize is planted at the beginning of April in the second year. Before maize planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as the base fertilizer, with a dosage of 5.04 kg / mu (calculated as pure nitrogen), and phosphate fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is applied as the base fertilizer. Then maize is planted flat, and the planting density is 4000 plants / mu.

[0096] During the large flare-up stage and filling stage of maize, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is topdressed, with dosages of 8.4 kg / mu (calculated as pure nitrogen) and 3.36 kg / mu (calculated as pure nitrogen) respectively.

[0097] The nitrogen application rate during the whole growth period of maize planting is 16.8 kg / mu, and the phosphorus application rate is 8.4 kg / mu.

[0098] (5) Conduct regular field management, during which no other fertilizers are applied. Harvest the corn at the beginning of October and count and calculate the corn yield.

[0099] Example 3

[0100] A method for reducing fertilizer use and increasing yield by straw returning:

[0101] (1) After harvesting the corn at the beginning of October in the first year, crush the corn straw to a length of 2 - 3 cm, then spray the purslane solution on the straw at a spraying rate of 50 kg / mu, and let it stand naturally for 30 d.

[0102] Preparation method of the purslane solution: Mix fresh purslane and water at a mass ratio of 1:8, crush with a pulverizer and filter with 8 - layer gauze to obtain the purslane solution.

[0103] (2) Spray the solution of the microbial growth promoter (prepared by mixing the microbial growth promoter with water, with a water consumption of 40 kg / mu) on the straw processed in step (1). The dosage of the microbial growth promoter is 1.0 kg / mu.

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

[0105] Preparation method of the starch ferment:

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

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

[0108] (3) After the solution of the microbial growth promoter sprayed in step (2) dries, spray the solution of the complex microorganism (prepared by mixing the complex microorganism with water, with a water consumption of 40 kg / mu). The dosage of the complex microorganism is 1.0 kg / mu. After drying, plow it into the soil (30 cm) and irrigate. The irrigation water consumption is 50 m 3 / mu.

[0109] Compound microorganisms, which are composed of the following components in parts by volume: 8 parts of Bacillus velezensis bacterial liquid, 3 parts of Azotobacter chroococcum bacterial liquid, 7 parts of Bacillus subtilis bacterial liquid, 4 parts of Lactobacillus plantarum bacterial liquid, 3 parts of Trichoderma reesei bacterial liquid, 1 part of Phanerochaete chrysosporium bacterial liquid, and 6 parts of Trichoderma harzianum bacterial liquid.

[0110] (4) Corn is planted in early April of the second year. Before corn planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as a base fertilizer at a rate of 5.04 kg / mu (calculated as pure nitrogen), and phosphate fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is applied as a base fertilizer. Then, the corn is planted flat, and the planting density is 4,000 plants / mu.

[0111] During the large bell mouth stage and filling stage of corn, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is topdressed at rates of 8.4 kg / mu (calculated as pure nitrogen) and 3.36 kg / mu (calculated as pure nitrogen), respectively.

[0112] The nitrogen application rate during the entire growth period of corn planting is 16.8 kg / mu, and the phosphorus application rate is 8.4 kg / mu.

[0113] (5) Conduct conventional field management. During this period, no other fertilizers are applied. Corn is harvested in early October, and the corn yield is statistically calculated.

[0114] Control 1

[0115] A corn planting method:

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

[0117] (2) Corn is planted in early April of the second year. Before corn planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as a base fertilizer at a rate of 7.2 kg / mu (calculated as pure nitrogen), and phosphate fertilizer (pure phosphorus P2O5, 12 kg / mu) is applied as a base fertilizer. Then, the corn is planted flat, and the planting density is 4,000 plants / mu.

[0118] During the large bell mouth stage and filling stage of corn, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is topdressed at rates of 12 kg / mu (calculated as pure nitrogen) and 4.8 kg / mu (calculated as pure nitrogen), respectively.

[0119] The nitrogen application rate during the entire growth period of corn planting is 24 kg / mu, and the phosphorus application rate is 12 kg / mu.

[0120] (3) Conduct conventional field management. During this period, no other fertilizers are applied. Corn is harvested in early October, and the corn yield is statistically calculated.

[0121] Control 2

[0122] A method for reducing fertilizer use and increasing yield by straw returning to the field:

[0123] (1) In early October of the first year, after the corn is harvested, the corn straw is crushed to a length of 2 - 3 cm, plowed into the soil (30 cm), and irrigated. The irrigation water consumption is 50 m 3 / mu.

[0124] (2) In early April of the second year, corn is planted. Before corn planting, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is applied as the base fertilizer, with a dosage of 5.04 kg / mu (calculated as pure nitrogen), and phosphate fertilizer (pure phosphorus P2O5, 8.4 kg / mu) is applied as the base fertilizer. Then, the corn is planted flat, and the planting density is 4000 plants / mu.

[0125] During the large bell - mouth stage and filling stage of corn, nitrogen fertilizer (urea containing 46.0% pure nitrogen) is top - dressed, with dosages of 8.4 kg / mu (calculated as pure nitrogen) and 3.36 kg / mu (calculated as pure nitrogen) respectively.

[0126] The nitrogen application rate during the whole growth period of corn planting is 16.8 kg / mu, and the phosphorus application rate is 8.4 kg / mu.

[0127] (3) Conventional field management is carried out. During this period, no other fertilizers are applied. The corn is harvested in early October, and the corn yield is statistically calculated.

[0128] Comparative Example 3

[0129] Same as Example 1, the only difference is that the Bacillus subtilis bacterial liquid is replaced with an equal volume of Bacillus thuringiensis bacterial liquid, and the Trichoderma harzianum bacterial liquid is replaced with an equal volume of Trichoderma viride bacterial liquid.

[0130] Comparative Example 4

[0131] Same as Example 1, the only difference is that the compound microorganism does not contain Bacillus velezensis bacterial liquid and Azotobacter chroococcum bacterial liquid.

[0132] Comparative Example 5

[0133] Same as Example 1, the only difference is that the purslane solution is not sprayed on the straw.

[0134] Comparative Example 6

[0135] Same as Example 1, the only difference is that the starch ferment is replaced with citric acid and water with a mass ratio of 1:4.

[0136] Comparative Example 7

[0137] Same as Example 1, the only difference is 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 corn planted in the examples and comparative examples (yield measurement is carried out when the moisture content is about 13%) are shown in Table 1.

[0139] Table 1 Corn yield

[0140]

[0141]

[0142] As can be seen from Table 1, the method of the present invention can reduce weight by 30% while increasing corn yield.

[0143] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection 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 It includes the following steps: In the autumn of the first year, spray purslane solution on crop straws, spray microbial growth promoter after natural standing, dry in the air, then spray compound microorganisms, plow into the soil, irrigate, and plant crops in the spring of the second year.

2. The method according to claim 1, characterized in that, The preparation method of the purslane solution includes the following steps: Mix fresh purslane and water, crush and filter to obtain the purslane solution.

3. The method according to claim 2, wherein The mass ratio of the fresh purslane to water is 1:(8 - 10).

4. The method according to claim 1, wherein The length of the straw is 2 - 3 cm; and / or, the time of natural standing is 25 - 30 d.

5. The method according to claim 1, wherein The microbial growth promoter includes the following raw materials in parts by mass: 40 - 50 parts of starch ferment, 6 - 8 parts of sunflower seeds, and 2 - 3 parts of soybeans.

6. The method according to claim 5, characterized in that, The preparation method of the starch ferment includes the following steps: Mix starch and water, add liquefying enzyme, filter after liquefaction to obtain the supernatant; Add soybean meal powder to the supernatant, mix evenly, sterilize, inoculate Aspergillus niger, and ferment to obtain the starch ferment.

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

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

9. The method according to claim 1, wherein The compound microorganisms include the following components in parts by volume: 5 - 8 parts of Bacillus velezensis, 3 - 4 parts of Azotobacter chroococcum, 5 - 7 parts of Bacillus subtilis, 4 - 5 parts of Lactobacillus plantarum, 3 - 4 parts of Trichoderma reesei, 1 - 2 parts of Phanerochaete chrysosporium, and 4 - 6 parts of Trichoderma harzianum.

10. 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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