CN115491331A - A microbial agent that promotes carbon emission reduction in rice straw returning to the field - Google Patents

Abstract

The invention discloses a microbial agent for promoting carbon emission reduction of rice straw returning, and belongs to the field of environmental protection. The invention aims at the defects of long period and slow decomposition of the rice straw returning technology and the problems of unstable carbon fixation, poor carbon emission reduction effect and the like of the existing microbial agent. The microbial agent of the invention is composed of 2-20% of bacillus subtilis, 2-20% of bacillus cereus, 2-20% of bacillus licheniformis, 1-10% of lactic acid bacteria, 1-10% of saccharomycetes, 2-20% of acetobacter pasteurianus and 5-30% of photosynthetic bacteria. The microbial agent disclosed by the invention selects various bacilli with strong cellulose degradation effect as a composite microbial agent main body, and matches beneficial bacteria such as lactic acid bacteria, saccharomycetes, acetobacter pasteurianus and photosynthetic bacteria, so that the action effect of microbial flora in returning rice straws to the field is fully exerted, soil nutrients are returned, the fertilizer consumption is saved, the physical and biological properties of soil are continuously improved, the activity of methanogens is inhibited, the generation of methane is reduced, and the stable carbon sequestration and resource utilization of returning rice straws to the field are realized.

Description

A microbial agent that promotes carbon emission reduction in rice straw returning to the field

technical field

The invention belongs to the use of biotechnology in the field of environmental protection, and in particular relates to a microbial bacterial agent for promoting the carbon emission reduction of rice straw returning to the field.

Background technique

Straw returning to the field is a measure of fertilization, carbon sequestration, and production increase that is widely valued at home and abroad. It can not only reduce the air pollution caused by straw open-air burning, but also increase soil organic matter through comprehensive utilization, improve soil structure, and make soil The increase of porosity can improve the quality of arable land, increase the soil carbon pool, and at the same time promote the activity of microorganisms and the development of crop roots, which is of great significance for stabilizing grain income, increasing carbon sequestration and pollution prevention.

However, according to the current research, the pure straw returning technology not only has defects such as long cycle, slow maturity, time-consuming and laborious, but also may lead to carbon dissipation due to methane production during decomposition and fermentation, making the final carbon sequestration effect unstable. The microbial agent can make full use of microbial activity and decomposition ability to quickly decompose cellulose, hemicellulose, and lignin in rice straw, and has good benefits in material transformation and carbon fixation. Therefore, it is of great significance to explore a microbial strain that can efficiently degrade crop straw and promote the carbon emission reduction of rice straw returning to the field to improve the current technology of rice straw returning to the field.

Contents of the invention

Aiming at the defects of long cycle and slow maturity of rice straw returning technology, as well as the problems of unstable carbon fixation and poor carbon emission reduction effect of existing microbial agents, the present invention develops a compound microorganism with simple preparation and stable efficacy by optimizing superior microbial strains Bacteria. The good synergistic relationship of a variety of active microbial strains can deal with the problems of insignificant effect, unstable activity, and poor adaptability of a single microbial agent. Insect eggs, bacteria and other pest problems, fertilizer preservation can promote the growth and development of rice in the coming year, and realize scientific rice straw returning to the field.

The key point of the application of the present invention is the selection of a microbial agent for promoting rice straw returning to the field to reduce carbon emissions. A variety of bacillus with strong cellulose degradation effects are selected as the main body of the compound agent, and lactic acid bacteria, yeast, pasteurized Beneficial bacteria such as Acetobacter and photosynthetic bacteria give full play to the role of microbial flora in rice straw returning to the field, return soil nutrients, save fertilizer consumption, continuously improve soil physical and biological properties, inhibit the activity of methanogens and reduce methane production, Realize the stable carbon sequestration and resource utilization of rice straw returning to the field. In addition, the microbial agent of the present invention also has a certain effect of inhibiting pathogenic bacteria, and can make the soil and subsequent crops have certain disease resistance and stress resistance, improve the quality of soil and crops, and develop "green agriculture".

According to the present invention, through the research on the technology of rice straw returning to the field and the principle of carbon fixation, combined with microbial technology and the physiological characteristics and habits of various types of bacteria, a composite microbial bacterial agent that promotes carbon emission reduction of rice straw returning to the field has been developed and prepared , which is composed of a variety of bacillus, lactic acid bacteria, yeast, Acetobacter pasteurianus, photosynthetic bacteria and other common fungi and bacteria in the soil. Rapid heating, deodorization, and dehydration at room temperature (above 15°C), degrades lignin, cellulose, and semi-fibers in straw, and completes decomposing in about a week. At the same time, it reduces the production of methane, ammonia nitrogen and harmful organic acids, increases the nutrient content and carbon content in the soil, and is conducive to the subsequent growth of crops and long-term fertilizer supply. The main active ingredients and proportioning range of the microbial agent of the present invention are as follows.

Table 1 The main active components of the composite microbial agent raw materials raw material percentage Bacillus subtilis 2%-20% Bacillus cereus 2%-20% Bacillus licheniformis 2%-20% Lactic acid bacteria 1%-10% Yeast 1%-10% Acetobacter pasteurianus 2%-20% Photosynthetic bacteria 5%-30%

Among the microbial agents of the present invention, Bacillus subtilis, Bacillus cereus, and Bacillus licheniformis are preferred, and the effective number of viable bacteria reaches 3 billion/g, which can significantly improve the efficiency of the compound microbial agent to decompose straw , degrade cellulose, sugar and starch, shorten the treatment cycle, quickly transform straw into nutrient-rich organic materials, increase soil total nitrogen, available phosphorus, organic matter and available potassium content, improve soil fertility, promote crop growth and play a role It has certain disease resistance.

The selected lactic acid bacteria of the present invention can use the carbon source in the straw to produce lactic acid through anaerobic fermentation, inhibit the reproduction of other harmful bacteria in the early stage of fermentation, and at the same time promote the fermentation of other bacterial species in the composite microbial agent. In addition, yeasts with strong vitality and high protein content are selected to secrete a variety of enzymes to ferment organic matter, and accelerate the maturity of rice straws to form high-quality fertilizers; during the subsequent natural growth of rice, yeasts can also be concentrated in crop roots Yeast-derived biostimulants and organic acids are produced around the environment to enhance the physiological functions of crops, the resistance to abiotic stress and the improvement of quality.

As an aerobic bacterium, Acetobacter pasteurian can use the metabolites produced by the bacteria in the early stage of straw fermentation to further oxidize and decompose, and the small molecule sugar alcohols produced can be oxidized into acetic acid and the like. It can also grow well in an acidic environment, and is suitable for continuous fermentation after the pH drops in the late stage of fermentation. It is one of the main functional bacteria in the middle and late stages of straw fermentation.

The photosynthetic bacteria in the present invention can improve the acidosis and hydrogen sulfide poisoning caused by fermentation and decomposing of the soil and water surface water before in-situ straw laying and transplanting, and provide sufficient oxygen for the soil and straw returning to the field to promote The growth and development of beneficial bacteria and subsequent seedlings.

The microbial bacterial agent of the present invention can effectively accelerate straw decomposition during the whole fermentation period through the synergistic effect of fungi and bacteria, and the bacteria strains are synergistically synergistic without growth inhibition and the like, which is beneficial to straw returning to the field. Secondly, a variety of Bacillus metabolites have a certain antibacterial effect, which can strengthen the inhibition of the reproduction of harmful bacteria and ensure the metabolism and growth of the complex microbial agent throughout the fermentation cycle.

The microbial agent of the present invention has a simple preparation process and is easy to produce and use. The strains shown above can be purchased from the China Forestry Microbial Strain Collection and Management Center or other market channels. After research and exploration of the ratio of microbial agents, an optimal ratio of microbial agents for promoting rice straw returning to the field for carbon emission reduction is given as follows:

Table 2 Optimum ratio of main active ingredients of compound microbial agent raw material percentage Bacillus subtilis 15% Bacillus cereus 15% Bacillus licheniformis 15% Lactic acid bacteria 10% Yeast 10% Acetobacter pasteurianus 15% Photosynthetic bacteria 20%

detailed description

Example 1

For the expansion and propagation of a single strain, the cultivation of a variety of Bacillus, Acetobacter pasteurianus and yeast is taken as an example to illustrate.

(1) Composition of solid medium for various bacillus: glucose 10.0g, peptone 15.0g, NaCl 5.0g, beef extract 10.0g, yeast extract 5.0g, agar 20.0g, distilled water 1000mL. (PH=7.0-7.2)

Specific operation: in an incubator at 15°C-40°C, inoculate the strains of Bacillus subtilis/Bacillus cereus/Bacillus licheniformis on the slant of nutrient agar medium under aseptic conditions for 24 hours, and then aseptically inoculate into the nutrient In the broth medium, the rotating speed r=120-200r/min shakes and cultivates for 24-48 hours, and finally inoculates on the solid medium and cultivates for 48 hours.

(2) Composition of the solid medium for Acetobacter pasteurianus: 20.0 g of glucose, 10.0 g of yeast extract, 15.0 g of calcium carbonate, and 20.0 g of agar. (PH=6.5-6.8).

Specific operation: Add this medium formula to 1L of distilled water or deionized water (tap water with high chlorine content should be left open for a day), stir and heat to boil until completely dissolved, then pack into triangular flasks and sterilize under high pressure at 121°C for 15 minutes. When cooled to about 30°C, inoculate Acetobacter slantii with 5% of the inoculum amount, rotate at r=120-200r/min and shake for 24-48 hours, and finally inoculate aseptically on solid medium for 48 hours of constant temperature fermentation at 30°C.

(3) Composition of solid medium for yeast: 50.0g glucose, 5.0g acid hydrolyzed casein, 0.5g KH2PO, 0.5g KCl, 0.2g CaCl, 0.2g MgSO4, 20g agar. (PH=5.5)

Specific operation: in an incubator at 12°C-36°C, inoculate yeast strains on the slant of yeast extract peptone glucose nutrient agar medium for 24 hours under aseptic conditions, and then aseptically inoculate them into soybean milk at a speed of r=120 Shake culture at -200r/min for 24-48 hours, and finally inoculate aseptically on solid medium for 48 hours.

The above nutrient agar medium consists of 10g of peptone, 3g of beef extract, 5g of sodium chloride, 15g of agar, add water to 1000ml, adjust the pH to 7.2, and autoclave at 121°C for 15min.

The above nutrient broth medium consists of 10g of peptone, 3g of beef powder, 5g of sodium chloride, adding water to 1000ml, adjusting the pH to 7.2, and autoclaving at 121°C for 15 minutes.

Example 2

(1) Composite Bacillus culture

The three types of bacteria in Example 1 (1) were mixed according to the mass ratio of 1:1:1, and were counted after expanding culture in the compound bacillus culture medium. The culture medium consists of: 10.0g soluble starch, 10.0g peptone, 5.0g yeast extract, 3.0g KH2PO4, 0.5g NaCl, 0.1g MgSO4. (PH=7.0-7.4)

(2) Compound microbial preparations

After activating the various strains in the corresponding medium and carrying out the enrichment and expansion, they were mixed according to the weight percentage in Table 2 (15% of Bacillus subtilis, 15% of Bacillus cereus, 15% of Bacillus licheniformis, 10% of lactic acid bacteria , 10% yeast, 15% Acetobacter pasteurianus, 20% photosynthetic bacteria), stir evenly and inoculate 10g of composite bacteria in a fermenter for 48-72 hours to make a composite enhanced microbial agent. Among them, the medium formula in the fermenter: 20.0g glucose, 15.0g brown sugar, 10.0g soluble starch, 10.0g peptone, 5.0g beef extract, 3.0g yeast extract, 2.0g KH2PO, 41.0g K2HPO, 15.0g agar, 1000mL distilled water , sterilized at 121°C for 20 minutes.

After the cultured microbial agent mixture is dried and crushed at room temperature, then an appropriate amount of lime is added for packaging, which is a compound microbial agent, and the effective number of viable bacteria can reach more than 7 billion/g. 6-12 months, the effect is best when used within one month.

Example 3

The difference from Example 3 is that the proportion of composite bacteria is: Bacillus subtilis 15%, Bacillus cereus 15%, Bacillus licheniformis 15%, lactic acid bacteria 10%, yeast 10%, Acetobacter pasteurianus 20%, photosynthetic Bacteria 15%

Example 4

The difference from Example 3 is that the proportion of composite bacteria is: Bacillus subtilis 15%, Bacillus cereus 15%, Bacillus licheniformis 15%, lactic acid bacteria 10%, yeast 10%, Acetobacter pasteurianus 10%, photosynthetic Bacteria 25%

Example 5

The composite microbial preparations in Examples 2, 3, and 4 of the present invention are used for rice straw returning to the field, and the straw can be mixed and spread or piled up and returned to the field, or the method of rotary tillage with stubble can be used. In Example 5, the direct original The use of microbial agents will be explained by taking the rice straw covered with the ground and returning it to the field as an example.

(1) Tiling the straw

After harvesting the rice, crush the rice stalks into 5-8 pieces and spread them evenly on the field to avoid piles of broken grass.

(2) Bacteria fertilization

After the straw is laid, mix the amount of 2 kg of microbial agent per mu with an appropriate amount of soil or base fertilizer and spread it evenly on the field where the straw is laid, and fertilize the base fertilizer according to the high-yield standard. At the same time, add farmyard manure 100- 200 kg or 3-5 kg of urea or 10-20 kg of ammonium bicarbonate to adjust the carbon-nitrogen ratio to avoid the phenomenon that microorganisms compete with the crop seedlings for available nitrogen during the decomposition process and affect the normal growth of crops.

(3) Stubble irrigation

Mechanically or manually beat the stalks for stubble removal, so that the rice stalks will settle into the surface soil, and raked in time to prevent the stalks from floating after soaking in water, so as to preserve moisture. The first irrigation is 7-10cm deep, so that the straw can fully absorb water, quickly heat up for fermentation, rot and decompose, and achieve stable carbon fixation.

(4) Sowing and management

After the straw is completely decomposed, it is plowed and leveled, and the soaked rice seeds are evenly spread on the ground (or transplanted) with irrigation water depth of 1-3cm. The sowing amount is about 10% higher than that of conventional cultivation methods. During the cultivation of seedlings, scientifically and rationally control the amount of water in the paddy field, and establish a shallow, dry, and wet flexible adjustment of paddy field CH4 low emission water management mode to reduce carbon emissions from straw returning to the field; other fertilization and pest and weed control are normal conduct.

In Example 5, there are slight differences in the effects of microbial agents with different proportions, but they can all achieve complete decomposition of rice straw in about 7 days, during which the production of methane, hydrogen sulfide and other substances is greatly reduced, which effectively promotes the return of rice straw to the field. carbon emission reduction, soil carbon sequestration and improvement; the growth of subsequent seedlings is also stronger, the rate of impact by insect pests is reduced, and the quality of rice is higher.

Claims (3)

1. A microbial inoculum that promotes rice straw returning to the field for carbon emission reduction is characterized in that by mass percentage, the microbial inoculum is composed of 2%-20% Bacillus subtilis, 2%-20% Bacillus cereus , 2%-20% Bacillus licheniformis, 1%-10% lactic acid bacteria, 1%-10% yeast, 2%-20% Acetobacter pasteurii and 5%-30% photosynthetic bacteria. 2. microbial inoculum according to claim 1 is characterized in that by mass percentage, described microbial inoculum is composed of 10%-20% Bacillus subtilis, 10%-20% Bacillus cereus, 10%- 20% Bacillus licheniformis, 5%-10% lactic acid bacteria, 5%-10% yeast, 10%-20% Acetobacter pasteurii and 15%-30% photosynthetic bacteria. 3. microbial inoculum according to claim 1 is characterized in that by mass percent, said microbial inoculum is composed of 15% bacillus subtilis, 15% bacillus cereus, 15% bacillus licheniformis, 10% Lactic acid bacteria, 10% yeast, 15% Acetobacter pasteurian and 20% photosynthetic bacteria.