He Suicheng, Shenyang Institute of Applied Ecology, Chinese Academy of Sciences

China is the largest developing country in the world with a large population. Eating, drinking and dressing are top priorities, so we must give priority to the development of agriculture. A basic requirement of China's national economy and Society for agriculture is to produce 20% of the world's grain with 6.8% of the world's arable land and 35% of the chemical fertilizer, and feed 22% of the world's population. Although China's total natural resources are large, the relative amount is small, and the per capita resource share is quite different from the world's average level. China is also a large country in the production and use of chemical fertilizer. In 2018, the amount of chemical fertilizer used nationwide reached 83.21 million tons, of which the largest amount of nitrogen fertilizer was 21.72 million tons. The input of chemical fertilizer accounted for about 50% of the cost of agricultural production materials. Farmers pay more than 140 billion yuan for chemical fertilizer every year. According to China's population growth and the development trend of grain production in the future, and with reference to the level of fertilizer consumption per unit area in developed countries, China's demand for fertilizer remains relatively stable.

The input of chemical fertilizer is so large, but the utilization rate is very low. The largest amount is nitrogen fertilizer, but the utilization rate of nitrogen is only 30-35%, that of phosphorus is only 20-30%, and that of potassium is 30-35%, which is about 10 percentage points lower than that of developed countries. After nitrogen fertilizer is applied to the soil, ammonia volatilizes and gaseous nitrogen escapes through nitrification and denitrification, causing serious pollution to rivers, groundwater and atmosphere.

In recent years, the country has advocated the substitution of organic fertilizer for chemical fertilizer. First of all, we should carry out the action of organic fertilizer replacing chemical fertilizer in fruits, vegetables, tea and other crops to reduce the excessive application of chemical fertilizer. In fact, after the fermentation and degradation of functional microbial agents, organic fertilizer can not only replace a part of differentiation fertilizer, but also improve the soil, fertilize the soil, improve the quality of crop products, improve the utilization rate of chemical fertilizer, and more importantly, reduce carbon emissions and achieve carbon neutralization and other comprehensive effects.

With the continuous improvement of intensive production of animal husbandry in China, the scale of animal husbandry is increasing day by day The number of poultry in 2018 increased five times over 2012, reaching more than 8 billion, and the number of pigs in 2018 increased 3.2 times over 2012, reaching 441.691 million; The number of cattle increased by 8 times to 132.058 million. The annual fecal output of chickens, pigs and cattle in China is 2.062 billion tons. It is estimated that 100 tons of ammonia and 30 tons of phosphorus are discharged into the environment by a pig farm with an annual feeding capacity of 10000 pigs. The annual emissions of ammonia and phosphorus from pig manure in China are about 10million tons and 2million tons respectively. If these wastes are not treated harmlessly, they will seriously pollute the surrounding environment and water sources.

With the adjustment of people's good food structure, animal husbandry will have a greater development in the future. With the increase of the number of livestock and poultry, the problem of manure treatment, especially for large cities, is very serious. Several large cities in Liaoning Province, such as Shenyang and Dalian, have large-scale animal husbandry. The chicken stock of a group in Dalian is more than 30million, the supply of eggs accounts for more than 50% of the total supply of eggs in Dalian, and the daily fecal excretion is more than 500 tons. With other farmers, the daily chicken manure emission in Dalian alone is more than 800 tons. The number of livestock and poultry in Shenyang is three times that in Dalian, with 33million chickens, 500000 cows, 600000 pigs, 12 intensive chicken farms, 8 pig farms, and 8 dairy bases. The daily discharge of livestock and poultry manure is more than 2000 tons. Such a large amount of livestock and poultry manure discharge poses a huge threat to the local ecological environment. If it is not properly handled in time, it will seriously pollute the environment. On the other hand, livestock manure is also a fertilizer resource placed in the wrong position. If handled well, it can turn harm into benefit and turn waste into treasure.

China is a large vegetable producing country. In recent years, with the continuous expansion of China's vegetable planting area and the continuous improvement of production, China is also faced with the problems of low quality vegetables, pesticide residues and unsafe consumption. In particular, the excessive content of nitrite and other substances in vegetables is very common. The nitrate content in vegetables in big cities such as Shanghai and Guangzhou exceeds the standard by 5-8 times, and poisoning incidents occur from time to time due to consumers' consumption of vegetables such as leeks and melons and fruits. Therefore, to solve the quality problems in vegetable production, only through the implementation of pollution-free and green vegetable production, can we optimize and improve the quality of vegetables, protect consumers' health and protect the ecological environment. In recent years, the production area of pollution-free and green vegetables in China has increased rapidly, and the number of certified green vegetable products has increased year by year. It is sure that pollution-free and green vegetables will become the direction of vegetable production in the future. Since 2017, the Ministry of agriculture has repeatedly required organic fertilizer to replace chemical fertilizer. First, about 30% of organic fertilizer was substituted for chemical fertilizer in fruits, vegetables and tea. By 2019, the action was extended to replace chemical fertilizer with organic fertilizer in crops such as rice.

At present, the diet structure of people in some developed countries has gradually transitioned to health care. The United States and European countries are rapidly adjusting their dietary structure from meat to vegetarian meat. Among them, vegetables play an irreplaceable role in human health. Therefore, the annual trade volume of vegetables in the world is increasing. China is the country with the largest variety of vegetables and the largest planting area in the world. In addition, China has superior natural conditions, abundant labor resources, and low vegetable production costs. The price of domestic vegetables is only 1 / 5-1 / 8 of that of foreign countries, so it has strong competitiveness. However, there is still a big gap between the requirements of high-grade and harmless vegetables in China and the international market. In order to solve this problem, we believe that in the planting process, pesticides with low toxicity and low residue should be used. In terms of fertilization, organic fertilizer fully fermented by microbial complex bacteria should be used together with an appropriate amount of inorganic nutrients, or bio organic inorganic compound fertilizer should be used. In this way, crops can be fully absorbed and utilized without adverse effects. According to relevant data, China's annual crop yield reduction is more than 30% due to the application of non decomposed farmyard manure. In view of this situation, Liaoning Deshen microbial Co., Ltd. developed microbial agents according to the quality requirements of green food for the production of bio organic hypertrophic area to promote the application of Solanaceous Vegetables. Through the determination of various indicators, the results showed that compared with inorganic fertilizer, bio organic compound fertilizer can improve the quality of Solanaceous Vegetables, the yield is not lower than that of inorganic fertilizer, and can meet the green food standard; The application of bio organic fertilizer can also improve soil fertility and improve soil. It has high economic benefits and is welcomed by farmers.

(I) development status and trends at home and abroad:

At present, facing increasingly serious environmental and resource problems, countries around the world will take large-scale substantive actions on the basis of implementing sustainable development strategies, and agriculture and food industry, as the primary industry sector, will be the key areas of action. The U.S. government has realized that conventional agriculture, which relies too much on modern commodity input, has potential, cumulative and diffusive hazards to resources, environment, food hygiene and human health, such as soil hardening, groundwater pollution, biodiversity reduction, etc. European Union countries have started to carry out more strict management on the use of chemical pesticides. For example, the Netherlands, as a country with a very developed animal husbandry, has also formulated strict requirements on the use of veterinary drugs. The Swedish government has decided to turn 10% of the cultivated land into ecological planting from 2000 to promote the development of ecological agriculture and ecological food in the country. The Australian federal government has put forward a national agriculture, forestry and fishery strategy for sustainable development and launched the "clean food" plan, with the primary goal of occupying the Asian market. Japan is also unwilling to lag behind. The Ministry of agriculture, forestry and fisheries has launched the development plan of "environmental friendly agriculture".

In China, pesticides and chemical fertilizers are the key in the planting process. Pesticides with low toxicity and low residue are used. In terms of fertilization, it is required to mainly degrade the decomposed livestock manure by beneficial microbial flora. However, the crops in China suffer more than 30% losses due to the application of non decomposed livestock manure every year, especially in the seedling stage. Therefore, it is very necessary to make use of fast decomposing bacteria to fully degrade fermented livestock manure to prepare bio organic fertilizer, fertilize the soil, improve the soil, so that it can be directly absorbed and utilized by crops without adverse effects on the environment.

The growth of crops requires the supply of various nutrient elements, and the source of nutrient elements is mainly the application of various fertilizers. Chemical fertilizer plays a major role in the increase of crop production. According to the statistical data of the United Nations Food and Agriculture Organization for many years, chemical fertilizer plays an important role in the increase of crop production, accounting for about 40%. However, after chemical fertilizer is applied to the soil, due to the constraints of its own performance and soil environmental conditions, the utilization rate of chemical fertilizer for crops in the current season is low. Taking the largest amount of nitrogen fertilizer as an example, the utilization rate of nitrogen fertilizer in China is only 30% - 35%, about 10 percentage points lower than that in developed countries; The utilization rate of phosphate fertilizer in the current season is only 20% - 30%; The utilization rate of potassium fertilizer in the current season is 35% - 40%. The low utilization rate of chemical fertilizer not only causes a lot of waste of chemical fertilizer, but also brings adverse effects on the ecological environment. In the 1970s, a pure nutrient could increase grain yield by 19.6 kg, but in the 1990s, a pure nutrient could only increase grain yield by 11.4 kg. It can be seen that the application amount is not in direct proportion to the increase in grain yield. Practice has proved that when the input and output of agriculture is relatively low, it will directly affect the enthusiasm of farmers to increase fertilizer input. According to the calculation, only when the ratio of the value of increased grain to the cost of purchasing chemical fertilizer is vcr>2 can the enthusiasm of farmers to increase fertilizer input be mobilized. China's input-output ratio is VCR ≈ 2, so it is difficult to stimulate farmers' enthusiasm for increasing fertilizer application.

(II) the role of microbial agents in the harmless treatment of livestock and poultry manure

Necessity of harmless treatment of livestock manure:

1.a large number of heavy metals remain in livestock manure, such as lead, mercury, chromium, arsenic, etc., which are harmful to human body.

2. there are a large number of pathogenic bacteria, Salmonella, Escherichia coli, H5N1 highly pathogenic avian influenza virus, a H1N1, Streptococcus suis, foot-and-mouth disease of cattle in livestock and poultry feces, which pose a great threat to the aquaculture industry.

3. livestock and poultry feces contain hippuric acid and allantoin. These substances will cause crops to burn seedlings without decomposition and transformation, resulting in a loss of 1.3 billion yuan annually.

4. the global consumption of antibiotic feed additives accounts for 45.8% of antibiotic consumption. Commonly used antibiotics include fosfomycin, tetracyclines, chloramphenicol, etc. some of these drugs are absorbed and digested by animals, and the remaining 30% remain in livestock and poultry feces.
Hong Kong and other places import a large number of meat products such as livestock and poultry from the mainland every year. They implement the European Union's testing standards and forbid meat such as eggs and poultry containing antibiotics from entering Hong Kong.
Compound microbial agents play an important role in the harmless treatment of livestock and poultry manure
(1) microbial agents can inactivate heavy metals in livestock manure,
(2) microbial agents can degrade uric acid and allantoin in livestock manure to avoid burning seedlings
(3) microbial agents can produce high temperature to kill pathogenic bacteria in livestock manure.
(4) microbial agents can degrade antibiotics in livestock manure.

(III) main contents and characteristics of the project

1.Main contents:
The project mainly takes livestock and poultry manure as the main body (mainly including chicken manure, pig manure, cow manure, etc.), after full fermentation and harmless degradation by fast decomposing bacteria, and then adds an appropriate amount of inorganic nutrition, humic acid nitrogen fertilizer synergist and phosphorus potassium chelating agent, so as to realize the scientific ratio of biology, organic and inorganic, and make pollution-free biological long-term organic fertilizer. According to the needs of the market, special bio organic fertilizers for various crops can also be prepared.

2. Main process characteristics:
(1) first add straw, mushroom bran and other auxiliary materials to the fresh livestock manure to reduce the moisture of the material to less than 50%, then add the fast decomposing bacteria FM (1:500), mix well and enter the sunlight greenhouse type fermentation workshop for fermentation, when the material temperature reaches 65 ℃. Start turning the material once. When the material temperature rises above 60 ℃ again, turn it over again, usually three times. When the material is loose and has no odor, it means that the fermentation process is over, and then the material can be discharged, sent to the curing workshop for curing, crushed and prepared into bio organic compound fertilizer.
(2) fermentation is divided into three stages: warming stage, high temperature stage and cooling stage.

3. Key points of fermentation process:
(1) measures to promote livestock manure fermentation
In order to promote the rapid fermentation of livestock and poultry manure, the rapid decomposition flora independently screened by our institute was added. At the beginning of fermentation, these microorganisms should be given the energy to propagate as soon as possible, promote the microbial propagation speed, shorten the time to reach the high temperature stage, and accelerate the full degradation of organic substances in the fermentation material.
(2) control the c/n in the fermentation material.
Fermentation process is a biochemical process that uses microorganisms to degrade livestock manure. In the metabolism of microorganisms and the synthesis of cellular substances, a large number of nutrient elements are required. Carbon is mainly used as energy for microbial activities, nitrogen is mainly used for the synthesis of cell protoplasm, and phosphorus is an important element composed of phosphoric acid and nucleus. The most important nutritional condition is the c/n of fermentation material. Generally, the most suitable c/n of fermentation material is 25-35.
(3) control the moisture in materials
The decomposition of livestock manure and the growth and reproduction of microorganisms in the fermentation process are inseparable from water. Moisture is the key to successful fermentation. The moisture is too high and the air permeability is not good, which is not conducive to fermentation. Too low moisture is not conducive to microbial activities. The suitable fermentation moisture of livestock manure is about 40-50%.
(4) control the temperature in fermentation
Temperature is an important factor affecting microbial activities. During the fermentation process, beneficial microorganisms decompose the organic matter in livestock manure and release heat, so that the material temperature rises. The increase of temperature can accelerate the fermentation speed, but the fermentation process is a biochemical process. When the temperature exceeds the limit temperature, the activity of microorganisms will be affected, and the fermentation speed will decrease instead. The suitable temperature in the high temperature stage is 55 ℃ ~ 65 ℃. Mechanical turning is the best way to adjust temperature and supply oxygen.
(5) enrichment of beneficial flora
In the process of fermenting and degrading livestock manure, on the one hand, a variety of functional microorganisms degrade the organic matter in fermented livestock manure; On the other hand, a variety of beneficial microorganisms propagate in livestock and poultry manure in large quantities, degrade livestock and poultry manure into bio organic fertilizer. These beneficial microorganisms include silicate bacteria that transform phosphorus and potassium substances in the soil, and actinomycetes that can increase the Antagonistic Ability of the soil. These microorganisms are applied into the soil with the degraded organic matter, which has a good control effect on a variety of soil borne diseases.

4. Scientific preparation:

Fast decomposing bacteria are used to decompose pig manure, chicken manure, cow manure and other livestock manure into nutrients that can be directly used by crops. Adding inorganic nutrition, nitrogen fertilizer synergist and phosphorus potassium chelating agent in appropriate amount, the fertilizer has slow-release and long-term effect. This cooperation significantly improves the utilization rate of chemical fertilizer and reduces the pollution of chemical fertilizer to the environment; In line with the national requirements for carbon neutralization and carbon emissions, we will increase crop production, improve crop quality, and increase agricultural production and income.