Agricultural non-point source pollution is characterized by dispersion, universality, uncertainty and hysteresis, involving many agricultural producers, and is a prominent difficulty in agricultural environment protection. In recent years, the country has introduced a series of policies to control agricultural non-point source pollution. With the implementation of water pollution prevention and control action plans, agricultural and rural pollution control action plans, and zero growth action of fertilizer and pesticide use, positive progress has been made in the prevention and control of agricultural non-point source pollution. However, from the perspective of total discharge of water pollutants, the discharge of agricultural pollutants in China is still at a high level, and it is necessary to promote the prevention and control of agricultural non-point source pollution with the spirit of nailing.

The technical path of agricultural non-point source pollution control is "source reduction recycling process interception end treatment". In this path, source reduction and recycling are closely related to the agricultural production end. Doing well can not only save the cost of agricultural production, but also reduce the emissions of non-point source pollutants such as nitrogen, phosphorus, and organic matter. Agricultural producers are willing to do so; However, process interception and terminal governance are engineering measures that require additional investment, and agricultural producers are usually unwilling to take the initiative. How to stimulate the endogenous motivation of agricultural producers to participate in the prevention and control of non-point source pollution and achieve twice the result with half the effort is an urgent problem that needs to be explored and solved. The author believes that source control is the key to preventing and controlling agricultural non-point source pollution. Therefore, the following suggestions are proposed:

One is to establish limit standards for the use of pesticides and fertilizers, as well as technical specifications for their scientific use. China's production and use of fertilizers and pesticides rank among the top in the world. The excessive investment and unscientific application of fertilizers and pesticides are the main reasons for non-point source pollution in the planting industry. According to the concept of "focusing on key areas, zoning governance, and fine management" for non-point source pollution control and supervision, relevant functional departments should, on the basis of accurately grasping the emission laws and bases of agricultural non-point source pollution, develop limit standards and specific feasible technical specifications and manuals for agricultural production inputs such as fertilizers and pesticides for key areas of non-point source pollution control. Under the premise of considering crop yield and minimizing pollutant emissions, corresponding regulations should be made in terms of farmland cultivation methods, crop variety selection, rotation types, fertilization methods, fertilization periods, fertilizer types, fertilizer dosage, plant protection measures, pesticide dosage, etc., so that agricultural producers have standards and technical support to reduce agricultural material input while controlling the generation of non-point source pollution from the source.

The second is to effectively stimulate the endogenous power of agricultural producers to control their sources. Whether agricultural producers are willing to use organic fertilizers and agricultural waste from livestock and poultry manure, and whether they are willing to take biological and physical measures to prevent diseases and pests, determines whether the measures for controlling non-point source pollution can be implemented. Organic products, green food, and good agricultural practices are all regulated through standard forms to pay attention to environmental protection in agricultural production. The use of chemically synthesized fertilizers and pesticides and other agricultural chemicals is prohibited or restricted, and agricultural, biological, and physical measures are adopted to prevent and control pests and diseases. Green manure is planted, organic fertilizer with livestock and poultry manure, straw and other agricultural waste as the main raw materials, or straw is returned to the field to fertilize the soil, These regulations are practical measures for controlling agricultural non-point source pollution. To pass the inspection and certification of certification agencies in agricultural production, it is necessary to comply with standards and actively adopt environmentally friendly green production methods as stipulated in the standards, in order to solve the problem of driving force for non-point source pollution control. Therefore, vigorously promoting the development of organic products, green food, and certified products with good agricultural standards can help stimulate the endogenous power of agricultural producers to control non-point source pollution.

The third is to improve the source control skills of agricultural producers through training. The "three rights separation" of rural land has promoted land circulation, accelerated the process of agricultural scale and intensive management, and agricultural enterprises, large planting households, family farms, and farmers' professional cooperatives have become the main new types of agricultural management entities. A group of non agricultural background operators who have received higher education and strong economic strength have joined agricultural production, and their advantage lies in being able to accept advanced knowledge and concepts, The disadvantage is not understanding agricultural technology knowledge. Therefore, it is necessary to establish a training mechanism for new agricultural business entities, help them enhance their awareness of green development in agriculture, master source control technologies for precise agricultural inputs, clean production, waste resource utilization, and ecological industrial models. Translate the technical methods of source control, emission reduction, and recycling into specific agricultural production practices, while promoting cost saving, quality improvement, and efficiency improvement in agriculture, significantly reducing the emissions of agricultural non-point source pollutants.

(Author's unit: Nanjing Institute of Environmental Science, Ministry of Ecology and Environment, xi yunguan)