A method for efficiently degrading and returning straw to fields

Abstract

The present invention relates to a method for returning straw degradation to the field, characterized in that the method comprises the following steps: kneading and crushing the straw raw material to a length of 1-2 cm, adding livestock and poultry manure, adding an appropriate amount of water and a straw fiber composite degradation agent, stirring and mixing evenly, piling up, fermenting for 6-8 days, turning over and throwing once, fermenting after 13-16 days, and the crude fiber micro-degradation rate of the straw is 70-80%; the straw fiber composite degradation agent comprises a composite bacterial agent and an activator of the composite bacterial agent, and the weight ratio of the composite bacterial agent to the activator of the composite bacterial agent is 1:4-6; the composite bacterial agent comprises a combination of Streptomyces, Oriental Acetobacter and Bacillus subtilis; the activator of the composite bacterial agent comprises raw sugar and nano humic acid. The method of the present invention has a reasonable strain ratio, fast bacterial growth rate, short temperature rise time, low requirements on environmental temperature and oxygen supply conditions, high straw degradation efficiency, low site requirements, simple preparation and low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and more specifically, relates to a method for efficiently degrading and returning straw to fields. Background Art

[0002] The existing methods of returning straw to the field mainly include: 1. Returning the straw to the field directly after crushing. 2. Returning the straw to the field after it is fully decomposed. Regarding returning the straw to the field after it is fully decomposed, there are a lot of literature reports on the prior art.

[0003] For example, Chinese patent CN102676492B discloses a highly efficient straw-degrading composite bacterial agent (JFB-1) and a method for preparing organic fertilizer thereof. The composite bacterial agent is composed of composite bacteria and a carrier, wherein the carrier is wheat bran, and the composite bacteria are composed of four composite bacteria, namely, I, II, III and auxiliary bacteria. Mixed bacterial agents I, II and III are taken at 1-1.5% of the weight of the straw, wherein the No. I bacterial agent accounts for 20-25%, the No. II bacterial agent accounts for 45-50%, and the No. III bacterial agent accounts for 30-35%, and are evenly added during composting and fermentation to effectively improve the maturation speed and quality of the organic fertilizer. The bacterial agent is fully mixed with the straw of crops such as rice and asparagus for composting and fermentation. Through the synergistic effect between multiple bacterial species, the straw can be quickly degraded, the degradation efficiency can be improved, the degradation time can be shortened, pests and diseases can be effectively killed, and the organic fertilizer for improving the soil can be quickly converted. The use of this highly efficient straw-degrading composite bacteria can effectively solve the problems of land occupation caused by landfill or fire, traffic hazards and environmental pollution caused by incineration.

[0004] For another example, Chinese patent CN106148224B discloses a straw-degrading acidifying bacterial agent and a method for manufacturing the same. The present invention provides a composite bacterial agent for degrading straw, the active ingredients of which are Cellulomonasflavigena, Clostridium cellulolyticum, Bacillussubtilis, and Bacilluscereus. The bacterial agent of the invention breaks through the limitation that fungi and their decomposing enzymes cannot quickly and efficiently decompose natural cellulose, provides a key pretreatment technology for straw biogas fermentation, and will have broad application prospects in the field of preparing biogas from straw and other lignocellulosic raw materials.

[0005] However, the prior art still has the following problems:

[0006] 1. The strain ratio is simple, the strains are not synergistic, and the enzyme production complementarity is not strong;

[0007] 2. The degradation rate of straw fiber is about 30 days. If the ambient temperature is lower than 15℃, the degradation time of straw fiber will be longer.

[0008] 3. High oxygen supply conditions are required. At present, the main bacterial agents for straw fiber degradation are aerobic bacteria. The straw cannot be piled too high and needs to be aerated or turned frequently, otherwise it will greatly affect the degradation of straw fiber:

[0009] 4. The lack of nutrients, promoters for the early growth of the inoculant and buffers for metabolites in the middle and late stages of fermentation affects the degradation rate of straw fiber;

[0010] 5. The efficiency of straw degradation is low. In an environment of about 20°C, it takes at least 30 days to degrade more than 70% of the straw fiber.

[0011] 6. The raw material ratio and bar coding method are unreasonable, the carbon-nitrogen ratio is unreasonable, and most of the fermentation is carried out in the fermentation tank with oxygen. The width-to-height ratio of the bar pile is too large, resulting in slow growth of various microorganisms, slow temperature increase, and a large number of fermentation dead corners. Harmful substances in the materials (harmful bacteria, grass seeds, insect eggs) are not completely killed, and the degradation rate of various macromolecular nutrients is slow. The nutrients do not meet the standards and the organic matter content is low.

[0012] 7. It has high requirements for production sites, requires factory buildings, fermentation tanks, oxygenation equipment and other related supporting equipment, has high production costs, and is difficult to apply in cost-sensitive production such as field crops.

[0013] In view of the above technical problems, the present invention provides a method for efficiently degrading and returning straw to fields. Summary of the invention

[0014] Based on the above background technology, the technical problem to be solved by the present invention is to provide a method for efficiently degrading and returning straw to the field. In order to achieve the purpose of the present invention, the following technical scheme is proposed:

[0015] One aspect of the present invention relates to a method for returning straw degradation to fields, characterized in that the method comprises the following steps:

[0016] 1000 parts by weight of straw raw material, rub and crush the straw raw material to a length of 1-2 cm, add 400-600 parts by weight of livestock and poultry manure, add appropriate amount of water and 1-3 parts by weight of straw fiber composite degradation agent, stir and mix evenly, make the moisture content of the material 60-70%, pile it high, ferment for 6-8 days, turn it over once, ferment after 13-16 days, and the crude fiber micro-degradation rate of the straw is 70-80%;

[0017] The straw fiber composite degradation agent comprises a composite bacterial agent and an activator of the composite bacterial agent, wherein the weight ratio of the composite bacterial agent to the activator of the composite bacterial agent is 1:4-6; the composite bacterial agent comprises a combination of Streptomyces, Acetobacter orientalis and Bacillus subtilis; and the activator of the composite bacterial agent comprises raw sugar and nano-humic acid.

[0018] In a preferred embodiment of the present invention, the weight ratio of Streptomyces, Acetobacter orientalis and Bacillus subtilis in the composite bacterial agent is 2-4:2-4:1-2.

[0019] In a preferred embodiment of the present invention, the weight ratio of raw sugar to nano-humic acid in the activator of the composite bacterial agent is 5:1-3; preferably 5:1.5-2.5.

[0020] In a preferred embodiment of the present invention, the average particle size of the nano-humic acid is 50-60 nm.

[0021] In a preferred embodiment of the present invention, the straw raw material is a combination of corn straw, rice straw and wheat straw.

[0022] Another aspect of the present invention also relates to the above-mentioned composite bacterial agent, which comprises a combination of Streptomyces, Acetobacter orientalis and Bacillus subtilis; preferably, the weight ratio of Streptomyces, Acetobacter orientalis and Bacillus subtilis in the composite bacterial agent is 2-4:2-4:1-2.

[0023] Another aspect of the present invention also relates to the above-mentioned composite straw fiber degradation agent, which comprises a composite bacterial agent and an activator of the composite bacterial agent.

[0024] Effects of the Invention

[0025] Compared with the prior art, the main beneficial effects of the present invention are at least in the following aspects:

[0026] 1. Reasonable strain ratio: Streptomyces, Oriental Acetobacter, and Bacillus subtilis can all produce cellulase, hemicellulase, and ligninase, and the enzyme activity and species of the three bacteria are highly complementary. Bacillus subtilis grows the fastest, followed by Oriental Acetobacter, and Streptomyces grows the slowest. In order to balance the growth of the three bacteria, the ratio of the three strains is different. When there is a lot of oxygen in the straw in the early stage of fermentation, Bacillus subtilis is an aerobic bacterium and grows very fast. Oriental Acetobacter and Streptomyces also grow under low oxygen conditions, and grow faster in the later stage.

[0027] 2. Fast bacterial growth and short temperature rise time: This straw fiber composite degradation agent not only contains a rationally proportioned bacterial agent, but also contains carbon source, nitrogen source, mineral elements and active biomass required for the early growth of the bacterial agent. These components are provided by raw sugar and nano-humic acid, which provide early nutrition for bacterial growth and promote the rapid growth of microorganisms in the bacterial agent. Within 24-30 hours, this composite bacterial agent enters a rapid growth period, and the temperature in the material pile can reach 40°C. The fermentation temperature rises very quickly, and the temperature of the material pile is stable at 65°C-75°C during the vigorous growth period of the bacteria.

[0028] 3. Low requirements on environmental temperature and oxygen supply conditions: This composite bacterial agent is suitable for a wide temperature range of 5℃-75℃ and can grow. Streptomyces and Oriental acetic acid bacteria also grow rapidly under low oxygen concentration conditions. Therefore, straw stacking fermentation does not require oxygenation and multiple turning of the pile, and the operation is simple during the production process.

[0029] 4. High efficiency of straw degradation: Streptomyces, Oriental Acetobacter and Bacillus subtilis all contain very rich cellulase, hemicellulase and ligninase. Bacillus subtilis produces enzymes very widely. In addition to the above three enzymes, it also produces protease, lipase, amylase and phytase. Although Streptomyces and Oriental Acetobacter do not produce enzymes as widely as Bacillus subtilis, they have rich production of cellulase, hemicellulase and ligninase. In addition, nano-humic acid contains very rich biologically active substances, which can improve the activity of enzymes. At the same time, nano-humic acid also has a very good slow-release effect on the metabolites produced during the fermentation process of the bacterial agent. Generally, about 70-80% of the straw fiber can be degraded in 10-15 days, so the straw degradation efficiency is high.

[0030] 5. Reasonable raw material ratio and balanced nutrition: This method calculates the carbon-nitrogen ratio to be about 25-30, which ensures the rapid growth of the bacteria and accelerates the degradation of various macromolecular nutrients. It can fully degrade 75% within 10-15 days and 90% within 30 days. After harmless return to the field, crops can absorb it quickly and the utilization efficiency is high.

[0031] 6. Low site requirements, simple production and low cost: the production site can be carried out on a large scale as long as the ground is flat. Large-scale composting and returning to the fields can be carried out on the idle land in winter. The straw is collected and stripped nearby in the fields, and the livestock and poultry manure is transported nearby, and the raw material cost is basically zero; the production process is simple and highly mechanized, mainly using forklifts and turners, without labor and low production costs; after composting in winter, it can be mechanically spread and returned to the fields nearby in spring, and the cost of returning to the fields is low. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Unless otherwise specified, the reagents involved in the embodiments of the present invention are all commercially available products and can be purchased through commercial channels.

[0034] Streptomyces: from Beijing National Microbiological Culture Collection Center. Latin name Streptomyces microflavus, strain number: CICC23626;

[0035] Bacillus subtilis: Source: Beijing National Microbiological Culture Collection Center. Latin name: Bacillus subtilis, strain number: CICC25064.

[0036] Acetobacter orientalis: Source: Beijing Bio-Bowei Biotechnology Co., Ltd. Imported from Germany, Latin name: Acetobacter orientalis

[0037] Raw sugar: also known as crude sugar or No. 2 sugar, refers to the sugar with a layer of molasses obtained by squeezing sugar from sugarcane or beet juice, simple crystallization, and centrifugal separation. It is used as raw sugar for reprocessing in sugar refineries. The raw sugar used in the present invention is cheap and contains rich trace elements, which can promote the growth of bacterial agents and accelerate the degradation of straw.

[0038] Example 1

[0039] (1) Ratio of composite bacterial agent: The weight ratio of Streptomyces, Acetobacter orientalis, and Bacillus subtilis is 4:2:2, and the concentration of each bacteria is 1 billion / g.

[0040] (2) The ratio of activator of the composite bacterial agent: raw sugar and nano-humic acid (particle size 50-60nm) are mixed in a ratio of 5:2.

[0041] (3) The mixed composite bacterial agent and the activator of the composite bacterial agent are mixed in a ratio of 1:5 and mixed evenly to obtain a composite straw fiber degradation agent.

[0042] (4) Rub and crush 1000 kg of corn stalks, rice stalks and wheat stalks to a length of 1-2 cm, add 500 kg of livestock and poultry manure, add appropriate amount of water and 2 kg of straw fiber composite degradation agent, stir and mix evenly, make the moisture content of the material 65%, pile it into 80 cm high, ferment for 7 days, turn it over once, and fermentation is completed after 15 days. The crude fiber degradation rate of the straw can reach 72%.

[0043] Example 2

[0044] (1) The weight ratio of Streptomyces, Acetobacter orientalis and Bacillus subtilis is 4:3:1, and the weight ratio of the activator of the composite microbial agent is 5:2: raw sugar and nano humic acid (particle size 50-60nm). The mixed composite microbial agent and the activator of the composite microbial agent are mixed in a ratio of 1:4 and uniformly mixed to obtain a composite straw fiber degradation agent.

[0045] (2) Rub and crush 1000 kg of corn stalks, rice stalks and wheat stalks to a length of 1-2 cm, add 400 kg of livestock and poultry manure, add appropriate amount of water and 2 kg of straw fiber composite degradation agent, stir and mix evenly until the moisture content of the material is 63%, pile it into a height of 80 cm, ferment for 7 days, turn it over once, and fermentation is completed after 15 days. The crude fiber degradation rate of the straw can reach 75%.

[0046] Example 3

[0047] (1) Streptomyces, Acetobacter orientalis, and Bacillus subtilis are mixed in a ratio of 4:2:1. The ratio of the activator of the composite microbial agent is 5:2 of raw sugar and nano-humic acid (particle size 50-60nm). The mixed composite microbial agent and the activator of the composite microbial agent are mixed in a ratio of 1:3 and mixed evenly to obtain a composite straw fiber degradation agent.

[0048] 2) Rub and crush 1000 kg corn stalks, rice stalks and wheat stalks to a length of 1-2 cm, add 600 kg livestock and poultry manure, add appropriate amount of water and 2 kg of straw fiber composite degradation agent, stir and mix evenly, make the moisture content of the material 62%, pile it up to 80 high, ferment for 7 days, turn it over once, and fermentation is completed after 15 days. The crude fiber degradation rate of the straw can reach 70%.

[0049] Comparative Example 1

[0050] The ratio of the composite bacterial agent: Streptomyces and Bacillus subtilis is 4:2, and the rest is the same as in Example 1. The fermentation is completed after 15 days, and the crude fiber degradation rate of the straw can reach 22%.

[0051] Comparative Example 2

[0052] Ratio of composite bacterial agent: only Streptomyces is used, and the rest is the same as in Example 1. The fermentation is completed after 15 days, and the crude fiber degradation rate of the straw can reach 15%.

[0053] Comparative Example 3:

[0054] The weight ratio of the composite microbial agent is 4:2:2, and the activator of the composite microbial agent is raw sugar. The mixed composite microbial agent and the activator of the composite microbial agent are mixed in a ratio of 1:5 to obtain a composite straw fiber degradation agent. The other parts are the same as those in Example 1. After 15 days, the fermentation is completed, and the crude fiber degradation rate of the straw can reach 32%.

[0055] The above describes the preferred embodiments of the present invention, but it is not intended to limit the present invention. Those skilled in the art may make improvements and changes to the embodiments disclosed herein without departing from the scope and spirit of the present invention.

Claims

1. A method for returning straw to fields by degradation, characterized in that: The method comprises the following steps: 1000 parts by weight of straw raw material, rub and crush the straw raw material to a length of 1-2 cm, add 400-600 parts by weight of livestock and poultry manure, add appropriate amount of water and 1-3 parts by weight of straw fiber composite degradation agent, stir and mix evenly, make the moisture content of the material 60-70%, pile it high, ferment for 6-8 days, turn it over once, fermentation is completed after 13-16 days, and the crude fiber micro-degradation rate of the straw is 70-80%; The straw fiber composite degradation agent comprises a composite bacterial agent and an activator of the composite bacterial agent, wherein the weight ratio of the composite bacterial agent to the activator of the composite bacterial agent is 1:4-6; the composite bacterial agent is composed of Streptomyces, Acetobacter orientalis and Bacillus subtilis; the activator of the composite bacterial agent comprises raw sugar and nano-humic acid; the weight ratio of Streptomyces, Acetobacter orientalis and Bacillus subtilis in the composite bacterial agent is 2-4:2-4:1-2; the weight ratio of raw sugar and nano-humic acid in the activator of the composite bacterial agent is 5:1-3; and the concentration of each bacterium in the composite bacterial agent is 1 billion / gram.

2. The method according to claim 1, wherein the average particle size of the nano humic acid is 50-60 nm.

3. The method according to claim 1, wherein the straw raw material is a combination of corn straw, rice straw and wheat straw.