At present, China’s agricultural and rural economic development has entered the best historical period, and grain production has achieved "11 consecutive increases", which has been stable at more than 1.2 trillion Jin for two consecutive years. At the same time, it has made great achievements and paid a huge price. The string of resource utilization is getting tighter and tighter, and the carrying capacity of the ecological environment is getting closer and closer to the limit. Facing the double "curse" of resource conditions and ecological environment, it is urgent to change the mode of agricultural development, strengthen the control of agricultural non-point source pollution, effectively promote the protection and control of agricultural ecological environment and promote the sustainable development of agriculture.
First, scientific graspAgricultural non-point source pollution situation, and effectively enhance the sense of urgency and responsibility of agricultural non-point source pollution prevention and control work.
The first national pollution survey showed that in 2007, the chemical oxygen demand (COD), total nitrogen and total phosphorus emissions from agricultural sources in China reached 13.2 million tons, 2.7 million tons and 280,000 tons respectively, accounting for 43.7%, 57.2% and 67.4% of the total national emissions respectively. Among them, livestock and poultry breeding sources account for 96% of agricultural source COD, and are the main "contributors" of agricultural non-point source pollution. Agricultural chemicals such as livestock and poultry, aquaculture, chemical fertilizers, pesticides and agricultural films are the main sources of pollution. Different from industrial point source pollution directly entering the water body through centralized sewage outlets, agricultural non-point source is decentralized, and its pollution process is not a simple direct causal relationship from agricultural production behavior to discharge, and finally to environmental impact. The research shows that 35% of nitrogen in farmland chemical fertilizer in China is utilized by crops in the current season, and most of the rest is retained in farmland soil, and a small amount flows into ditches, and finally less than 5% enters the surface water body through runoff. Therefore, although the total amount of agricultural source pollutants discharged in China is relatively high, the amount that actually enters the water body is still very limited.
At present, the situation of agricultural non-point source pollution is generally grim, but there are also some particularities, which require us to make careful judgments and make precise policies.
First, the intensive degree of aquaculture is getting higher and higher. Due to the low resource utilization rate of livestock manure and other wastes, pollution emissions are on the rise.In recent years, the total amount of livestock and poultry breeding in China has been increasing. In 2013, the number of live pigs slaughtered in China exceeded 700 million. At the same time, the scale and intensification have developed rapidly, and the proportion of large-scale breeding of more than 500 pigs per year has reached 40.8%. At the same time, the construction of livestock waste treatment facilities is relatively backward, and a large amount of livestock manure is difficult to be treated and utilized in time, which makes livestock waste change from traditional farmyard manure to pollutants. In addition, the scale of aquaculture in China is also expanding rapidly. In 1978, the total amount of aquatic products was 4.654 million tons, of which artificial aquaculture accounted for 26.1%. In 2013, the total amount of aquatic products reached 61.72 million tons, accounting for 73.6%. A large number of bait and fish medicine were put into aquaculture, which caused water pollution.
Second, the amount of chemical fertilizer used in the main grain crops is basically reasonable, and the phenomenon of excessive application of economic crops such as vegetables and melons is more prominent. On the whole, the growth rate of chemical fertilizer consumption is declining, but the amount of chemical fertilizer input is still too large.In 2013, the amount of chemical fertilizer used in China was 59.12 million tons, accounting for 35% of the world. Based on 2.03 billion mu of cultivated land, the average amount of chemical fertilizer used per unit area reached 436.8 kg/ha, which was far higher than the world average. It is worth pointing out that at present, the average amount of nitrogen fertilizer used in China’s main grain crops is about 212 kg/ha, which is lower than the upper limit of environmental safety (the upper limit of safety set by developed countries for preventing water pollution is 225 kg/ha), but the average amount of nitrogen fertilizer used in fruit trees and vegetables is far higher than the environmental safety requirements, and the phenomenon of excessive application of chemical fertilizers in orchards and protected vegetables is still prominent.
Third, the use of pesticides per unit area is higher than the world average, but lower than that of developed countries such as the United States. The overall usage tends to be stable, but the utilization rate is low.In recent years, the amount of pesticides used in China has stabilized at about 320,000 tons (active ingredients), accounting for 1/7 of the total amount of pesticides used in the world, which is higher than the proportion of China’s land area to the world’s cultivated land area, which is related to the high land multiple cropping index in China. Generally speaking, China’s pesticide consumption per unit area is higher than the world average, but lower than that of developed countries such as the United States, Israel and Japan. On the other hand, at present, the utilization rate of pesticides in China is low, only 35%. Residual pesticides enter water bodies through precipitation, surface runoff and soil infiltration, which will lead to the deterioration of soil and water environment quality, destroy ecology and affect biodiversity.
Fourth, the recovery rate of plastic film is low, and the problem of residual old agricultural film still needs to be solved.China’s total use of plastic film and crop coverage area rank first in the world. In 2013, the consumption of agricultural film in China was 2.493 million tons. Due to the extensive use of ultra-thin plastic film and the lack of recycling technology and mechanism of residual film, the "white revolution" gradually evolved into "white pollution", and the problem of residual pollution of farmland plastic film became increasingly prominent. Plastic film residue is serious, affecting soil structure and reducing cultivated land quality; Affect the emergence of seedlings, resulting in reduced production; Affect the operation of agricultural machinery, resulting in a decline in the quality of sowing and fertilization; Livestock eating by mistake occurs constantly, which is harmful to livestock health.
Fifth, the comprehensive utilization rate of crop straw is low, and the recycling capacity needs to be improved urgently.Crop straw is a versatile agricultural resource. It is estimated that in 2013, the total output and collectable amount of straw in China were 964 million tons and 819 million tons, respectively. The actual utilization amount was about 622 million tons, and the comprehensive utilization rate was only 76%. With the change of agricultural energy structure, the proportion of crop straw in domestic energy is less and less. The way out for excess straw is: firstly, burning on the spot will cause air pollution, reduce atmospheric visibility, hinder traffic and endanger human health; Second, abandoned fields or piled into rivers or lakes, after weathering, rain and decay, the organic matter in straw enters the water body and causes pollution.
Generally speaking, with the continuous improvement of agricultural intensification and the rapid development of aquaculture in China, the problem of agricultural non-point source pollution caused by excessive use of agricultural inputs such as chemical fertilizers and pesticides and unreasonable disposal of agricultural wastes such as livestock manure, crop straws and farmland plastic film residue has become increasingly prominent, which seriously restricts the sustainable development of agriculture and rural economy. Therefore, strengthening the control of agricultural non-point source pollution is a realistic need to ensure the safety of agricultural products, realize China’s food security and quality safety of agricultural products, and is an internal need to improve the agricultural ecological environment, accelerate the transformation of agricultural development mode and realize the sustainable development of agriculture. We must scientifically grasp the increasingly serious situation of agricultural non-point source pollution, deeply understand the great significance of strengthening the control of agricultural non-point source pollution, and earnestly enhance the sense of urgency and responsibility in our work.
Two, the agricultural ecological environment protection and governance work has made positive progress, laying a solid foundation for the prevention and control of agricultural non-point source pollution.
Agricultural non-point source pollution in China is a long-term accumulation, which has its particularity and complexity. It can’t be completely solved overnight, and it needs a long period of unremitting efforts. In recent years, while ensuring the development of agriculture, agricultural departments at all levels have continuously increased the protection and governance of agricultural ecological environment, initially established a team of agricultural non-point source pollution prevention and control and expert support teams, and gradually established and improved the policy system, exploring and forming a number of practical technologies and typical models, which have laid a good foundation for the fight against agricultural non-point source pollution.
First, the construction of the system team has been continuously strengthened.A four-level agricultural environmental protection management system has been formed, with two state-level main stations as the leader, 33 agricultural environmental protection stations in provinces, autonomous regions, municipalities directly under the Central Government and cities under separate state planning as the main body, and 326 prefecture-level stations and 1794 county-level stations as the basis, which provides a team system guarantee for agricultural ecological environment monitoring and prevention and control.
Second, the monitoring and early warning capabilities have been continuously improved.A national agricultural non-point source pollution monitoring network has been initially established, and the normal and institutionalized operation of agricultural non-point source pollution monitoring has been continuously promoted; A four-level cultivated land quality monitoring network at the national, provincial, municipal and county levels has been established, and an annual report on national cultivated land quality monitoring has been issued; An environmental monitoring network system covering China’s offshore bays, islands and reefs, beaches, nature reserves, aquatic germplasm conservation zone and aquaculture waters has been initially formed, and the Bulletin on Fishery Ecological Environment in China has been issued regularly. A national monitoring network for pollution of agricultural products was established to carry out heavy metal pollution investigation in the producing areas.
Third, vigorously promote the scientific application of chemical fertilizers and pesticides.Comprehensively popularize the technology of soil testing and formula fertilization, with the promotion area reaching 1.4 billion mu; In-depth implementation of green prevention and control, the establishment of 150 national green prevention and control demonstration zones, the gradual elimination of 33 kinds of highly toxic pesticides, and vigorously promote the use of high-efficiency, low-toxicity, low-residue and biological pesticides; Carry out the integration of specialized unified prevention and control of crop pests and diseases with green prevention and control, promote pilot construction, and establish 218 demonstration bases; At the beginning of 2015, the Action Plan for Zero Growth of Fertilizer and Pesticide Use by 2020 was issued, and the zero growth of fertilizer and pesticide use was initiated.
Fourth, actively promote pollution prevention and control of livestock and poultry breeding.Accelerate the standardization of livestock and poultry breeding, create 3,397 standardized demonstration sites, and effectively improve the level of pollution prevention and control of livestock and poultry breeding; Start the pilot project of comprehensive utilization of livestock and poultry waste; Develop rural biogas projects according to local conditions and improve the sewage treatment capacity of rural farming manure.
The fifth is to carry out comprehensive utilization of straw in depth.Implement the comprehensive utilization project of straw, focusing on supporting Beijing-Tianjin-Hebei and other areas to carry out straw returning to the field, raising livestock, straw biogas, straw replacing wood, straw carbonization and other work; We will start the construction of a demonstration area for full quantitative utilization of straw at the township level in Beijing, Tianjin and Hebei, and accelerate the scale and industrialization of straw utilization.
Sixth, efforts should be made to solve the pollution of farmland residual film.Revise the standard of plastic film to solve the problem that residual film is easy to break and difficult to recycle; For four consecutive years, the agricultural cleaner production demonstration project focusing on the recycling of waste plastic film was implemented, and the plastic film recycling and processing system was initially established; Arrange subsidies for dry farming technology such as plastic film mulching in northwest and north China to promote the popularization and application of high-standard plastic film; The comparative test of degradable plastic film was started, and the degradable plastic film with good application effect was screened for demonstration and popularization.
Seventh, work together to promote the demonstration construction of comprehensive management of agricultural environment.A typical driving system of modern eco-circular agriculture has been formed, which consists of 1 eco-circular agricultural pilot province, 10 circular agricultural demonstration cities, 283 national modern agricultural demonstration zones, 1,100 beautiful countryside and several eco-agricultural demonstration bases. In key river basins and important water source protection areas, we will implement the construction of demonstration zones for the comprehensive prevention and control of livestock and poultry breeding wastes and agricultural nitrogen and phosphorus pollution, and actively explore effective mechanisms for the prevention and control of agricultural non-point source pollution in river basins.
To sum up, in recent years, the positive results of agricultural ecological environment protection and governance, as well as the continuous improvement of agricultural production and income and rural development, have made us more qualified, capable and confident to fight the tough battle of agricultural non-point source pollution prevention and control.
Three, to "one control, two reduction and three basics" as the key task, to fight the battle against agricultural non-point source pollution.
Since the 18th National Congress of the Communist Party of China, General Secretary of the Supreme Leader and other central leading comrades have repeatedly made important instructions on the protection and governance of agricultural ecological environment. General Secretary of the Supreme Leader pointed out that agricultural development should not only put an end to the new debts owed by the ecological environment, but also gradually pay back the old debts, and fight a tough battle for agricultural non-point source pollution control. Premier Li Keqiang proposed that the deterioration of resources and environment should be resolutely suppressed and the overdrawn resources and environment should be rehabilitated. In order to implement a series of deployment requirements of the CPC Central Committee and the State Council, at the beginning of this year, the Ministry of Agriculture, together with relevant departments, successively issued the National Agricultural Sustainable Development Plan (2015-2030), the Agricultural Prominent Environmental Problems Control Plan (2015-2018) and the Implementation Opinions of the Ministry of Agriculture on Fighting the Fight against Agricultural Non-point Source Pollution. Recently, a national on-the-spot meeting on accelerating the transformation of agricultural development mode and a national conference on the protection and governance of agricultural ecological environment have been held in Sichuan, which is an important meeting with milestone significance in the development process of modern agriculture in China. The promulgation of these documents and the convening of the conference have fully deployed and mobilized the protection and governance of agricultural ecological environment. At present, the most important task is to focus on the goal of "one control, two reductions and three basics" and fight a tough battle against agricultural non-point source pollution.
First, vigorously develop water-saving agriculture.Facing the severe situation of increasingly scarce water resources, it is necessary to increase efforts to develop water-saving agriculture. By strengthening the demonstration of water-saving agriculture, actively promoting water-saving varieties, integration of water and fertilizer, circulating aquaculture and other technologies, the utilization efficiency of water resources will be improved in an all-round way. Actively promote the comprehensive reform of agricultural water price. Coordinate the promotion of water ecological protection and management in river basins, and actively carry out the construction of demonstration zones for comprehensive prevention and control of agricultural non-point source pollution in key river basins such as Taihu Lake, Erhai Lake, Chaohu Lake and Three Gorges Reservoir Area. By 2020, the national agricultural irrigation water consumption will be controlled within 372 billion cubic meters, and the effective utilization coefficient of farmland irrigation water will reach 0.55.
The second is to implement the zero growth action of chemical fertilizers.The key to reducing fertilizer application is to establish the concept of green yield increase, vigorously promote scientific fertilization, improve the accuracy and utilization rate of fertilizer use, and encourage farmers to use more green manure and farmyard manure. The key point is to expand the application scope of soil testing and formula fertilization, and promote the formula fertilizer to enter the village and enter the field. At the same time, it is necessary to actively promote the research and development and promotion of new fertilizer products, and integrate and promote high-efficiency fertilization technologies such as simultaneous sowing of seeds and fertilizers and deep application of fertilizers. It is necessary to combine the construction of high-standard farmland, vigorously carry out the action of protecting and improving the quality of cultivated land, study and use subsidies to encourage and guide farmers to promote straw returning, planting green manure, accumulating farmyard manure and increasing the application of organic manure, rationally adjust the fertilization structure, and strive to improve the internal quality of cultivated land. Strive to achieve more than 90% coverage of soil testing and formula fertilization technology, more than 40% utilization rate of chemical fertilizers, and zero growth in the use of chemical fertilizers for major crops in China by 2020.
The third is to implement the zero growth action of pesticides.Adhere to comprehensive management, treat both the symptoms and the root causes, and realize scientific and accurate drug application. Strengthen the management of pesticide use, strengthen source management, and standardize farmers’ use of pesticides. Fully implement the fixed-point management of highly toxic pesticides and establish a traceability system for highly toxic pesticides. We will implement pilot projects for the use of low-toxic and low-residue pesticides, gradually expand the scope of subsidy projects, and accelerate the popularization and application of biological pesticides and high-efficiency, low-toxic and low-residue pesticides. Encourage agricultural socialized service organizations to provide guidance and services for farmers to use pesticides, and vigorously promote the integration of specialized unified prevention and control and green prevention and control. Ensure that by 2020, the coverage rate of green prevention and control of major crop pests and diseases will reach more than 30%, the utilization rate of pesticides will reach more than 40%, and the use of pesticides for major crops in China will achieve zero growth.
The fourth is to promote the prevention and control of aquaculture pollution.Overall consideration of environmental carrying capacity and pollution prevention requirements of livestock and poultry breeding, scientific planning and layout of livestock and poultry breeding. Promote standardized scale farming, supporting the construction of treatment and utilization facilities, improve facility farming technology, improve technical and equipment conditions, and encourage and support the implementation of household collection and centralized treatment of livestock and poultry manure in densely populated areas. Strengthen the construction of demonstration farms for healthy aquaculture, and popularize aquaculture technologies such as industrialized circulating aquaculture, pond ecological circulating aquaculture and bottom sewage of large-surface cage aquaculture. By 2020, more than 75% of large-scale livestock and poultry farms (districts) will build supporting facilities for waste storage, treatment and utilization.
Fifth, efforts should be made to solve the residual film pollution in farmland.Accelerate the revision of mulching film standards, strictly stipulate the thickness and tensile strength of mulching film, prohibit the production and use of substandard mulching film, and ensure that the residual mulching film in farmland can be recycled from the source. Increase financial support for technical subsidies for dry farming. Carry out regional demonstration of farmland residual film recycling, support the construction of plastic film recycling outlets and waste plastic film processing capacity, gradually improve the recycling network, and innovate the plastic film recycling and reuse mechanism. Accelerate the research and development of eco-friendly degradable plastic film and plastic film residue picking and processing machinery, and establish and improve the evaluation system of degradable plastic film. Ensure that by 2020, the recovery rate of agricultural film will reach more than 80% in the current season.
Sixth, carry out in-depth utilization of straw resources.According to the idea of "policy support, demonstration and guidance, focusing on agriculture, industrial development and market operation", we will promote the full utilization of straw "five materials" according to local conditions. It is necessary to further support the demonstration of new technologies such as straw harvesting machinery returning to the field, green and yellow storage for feed, microbial decay and solidification carbonization gasification, and study and introduce policies and measures such as enjoying the price of agricultural electricity for straw primary processing, incorporating storage and storage land into agricultural land management and credit support. Accelerate the establishment of a market-oriented mechanism for straw storage and transportation, reduce the cost of storage and transportation, and promote the scale and industrialization of comprehensive utilization of straw. In the key areas of air pollution, start the construction of demonstration counties for comprehensive utilization of straw, and fundamentally solve the problem of open burning of straw. Achieve the goal that the comprehensive utilization rate of straw will reach over 85% by 2020.
Agricultural non-point source pollution control is a tough battle and a protracted war. We need to base ourselves on the present and focus on the long-term. We should focus on five "enhancements" and five "enhancements", strengthen top-level design, increase planning and implementation, strengthen legal promotion, increase supervision and law enforcement, strengthen financial security, increase social participation, strengthen monitoring and early warning, increase scientific and technological support, strengthen policy creation, increase supervision and assessment, and take multiple measures to ensure implementation.
