How to prevent and control non-point source pollution when returning to "green" agriculture?

It is reported that agriculture has overtaken industry to become the largest non-point source pollution industry in China. Why should agriculture, which is supposed to be green and healthy, become an accomplice to pollution? How to break agricultural non-point source pollution and return the earth to a natural and refreshing face?

[status quo]

The first agriculture in the world has surpassed industry to become the largest non-point source pollution industry.

At present, agriculture has surpassed industry to become the largest non-point source pollution industry in China. "Agricultural non-point source pollution is of many kinds and widely distributed, and the overall situation is not optimistic." Zhang Taolin, vice minister of agriculture, said.

Northwest arid area: the problem of agricultural film pollution and white pollution is prominent.

Central and eastern regions: the problem of non-point source pollution of pesticides and fertilizers is prominent

Southern region: the pollution problem of agricultural livestock and poultry manure is prominent

The biggest characteristic of agricultural non-point source pollution is hidden, long-term and decentralized, which is produced consciously or unconsciously in every process of agricultural production, so it is troublesome to deal with it. Experts say that China uses a large amount of chemical fertilizers and pesticides, and its production and use are the first in the world. However, the utilization rate of chemical fertilizers and pesticides is 15%, 20% lower than that of developed countries, so it is imperative to reduce the amount of use and improve the utilization rate.

Heavy metal pollution has become an "invisible killer" of agricultural product quality.

According to the National soil pollution investigation Bulletin issued by the Ministry of Environmental Protection and the Ministry of Land and Resources, the overall soil environment in the country is not optimistic. The soil pollution in some areas is serious, and the over-standard rate of cultivated soil is 19.4%. The main pollutants are cadmium, nickel, copper, arsenic, mercury, lead, DDT and polycyclic aromatic hydrocarbons.

Experts pointed out that the "invisible" heavy metal pollution is acting as an "invisible killer" of the quality and safety of agricultural products, which may not only affect farmland and the surrounding environment in rural areas, but also make ordinary consumers have doubts about the quality and safety of agricultural products. "in addition to the soil heavy metal pollution caused by the discharge of industrial wastes, the massive input of agricultural chemicals will lead to land pollution caused by the enrichment of nutrients, heavy metals and toxic organic compounds in the soil, which will directly threaten the quality and safety of agricultural products." Said Zhang Fusuo, a professor at China Agricultural University.

[prevention]

"one reduction, two controls and three fundamentals"

China's agricultural resources and environment are suffering from the dual pressure of exogenous pollution and endogenous pollution, and the sustainable development of agriculture has encountered bottlenecks. In order to curb the expanding trend of agricultural non-point source pollution, the Ministry of Agriculture issued the opinions on the implementation of the battle for the prevention and control of agricultural non-point source pollution. The "opinions" put forward the objectives of "one control, two reductions and three basic" for the prevention and control of agricultural non-point source pollution: "one control" means to strictly control the total amount of agricultural water consumption and vigorously develop water-saving agriculture; "two reductions" means to reduce the use of chemical fertilizers and pesticides and implement zero growth in chemical fertilizers and pesticides; and the "three fundamentals" refers to the basic resource utilization of livestock and poultry manure, crop straw, and agricultural film.

Foreign experience can be used for reference.

According to the investigation and evaluation report of the United States in 1990, non-point source pollution in the United States accounted for about 2% of the total pollution, of which agricultural non-point source pollution accounted for 68%-83% of the total non-point source pollution, resulting in 50%-70% of surface water body being polluted or affected. After years of effective control, agricultural non-point source pollution in the United States has been greatly reduced. According to statistics in 2006, the area of agricultural non-point source pollution in the United States was 65% less than that in 1990. So what are the measures taken by the United States?

First, policies and measures. The United States has a systematic legal framework for agricultural pollution control. The first non-point source pollution control law was enacted in 1936 and has been revised many times. In addition, the US Environmental Protection Agency has implemented non-point source pollution management programs, and the Department of Agriculture has implemented rural clean water programs, national irrigation water quality plans, agricultural soil and water conservation plans, and other national functional departments, such as the Clean Water Act, maximum daily load plan, pesticide implementation plan, etc., and actively encourage farmers to take the initiative to control agricultural pollution, which plays an important role in reducing non-point source pollution. For those who voluntarily take measures for the prevention and control of non-point source pollution, the government will share part of the cost; for those who voluntarily take other measures, the government will grant tax relief and other policies.

Second, technical measures. The simple and cheap alternative technology is the key to the control of agricultural non-point source pollution. In the United States, there is no or little subsidy to farmers in agricultural non-point source pollution control, mainly to encourage farmers to voluntarily adopt environmentally friendly alternative technologies. The management measures for non-point source pollution targets include two types: engineering and non-engineering. Engineering measures include constructed wetlands, vegetation filter belts and grasslands, riparian buffer zones, rainstorm accumulation ponds and sedimentation ponds, and non-engineering measures include no-tillage-less tillage, comprehensive management of harmful substances, reuse of biological wastes and so on. The Ministry of Agriculture has set up special funds to support farmers in developing ecological agriculture to reduce non-point source pollution, and the Bureau of soil and Water Conservation provides technical guidance to help local governments control soil erosion. The Ministry of the Interior and the Environmental Protection Administration provide intelligence and information for water resources planning and non-point source control of different scales and levels.

Third, other measures. The United States has launched the operation modes of bio-agriculture, organic agriculture, renewable agriculture and green agriculture, which can effectively control the release of highly toxic pesticides in agricultural production in terms of law and technology.