On April 22, the Ministry of Ecology and Environment announced the environmental quality of surface water in China from January to March this year. From January to March, 88.2 percent of 3,641 national surface water assessment sections had excellent water quality (class ⅰ to ⅲ), up 5.2 percentage points year on year. The proportion of inferior ⅴ sections was 1.0%, down 1.1 percentage points year-on-year.
On the whole, the quality of water environment is improving. However, some unbalanced and uncoordinated problems can be seen from the land with poor water environment in China. The Ministry of Ecology and Environment said the quality of water in some sections has rebounded, efforts to eliminate substandard V quality in some areas are lagging behind, and problems such as "dirty and dirty" in the dry season and "zero storage and collection" in the rainy season are prominent. The Ministry of Ecology and Environment further analyzed that urban and rural non-point source pollution is rising as the main contradiction restricting the continuous improvement of water environment.
As the environmental protection industry has gradually penetrated into rural areas, agricultural non-point source pollution has become the topic center of non-point source pollution. A few years ago, when explaining the situation of China's agricultural non-point source pollution, the vice minister of agriculture said frankly that China's agricultural non-point source pollution as a whole is not optimistic. Since then, the battle against agricultural non-point source pollution has stepped into an accelerated gear. Recently, agricultural non-point source pollution prevention and control technologies and measures have emerged, striving to solve agricultural non-point source pollution as soon as possible.
For example, in order to reduce the pollution of soil environment caused by plastic film covering, the agricultural department of Fuding City, Fujian Province, for the first time started to implement the experiment of potato biodegradable film planting, which has generated carbon dioxide and water and river humus, greatly reducing the impact on the environment.
For example, the simultaneous side-deep fertilization technology of mechanized rice transplanting vigorously promoted by Zhuhai city in Guangdong Province has not only realized the comprehensive, high-quality and efficient development of agricultural mechanization, but also provided feasible experience for the control of agricultural non-point source pollution.
Agricultural non-point source pollution will directly affect water quality, and it is difficult to control the pollution. The current experience is not rich enough, and the problem of non-point source pollution still needs to be solved for a long time to stabilize the underlying forces.
In the face of agricultural non-point source pollution, some people in the industry have put forward a "point source treatment" scheme for agricultural non-point source pollution. In his opinion, the main difference between non-point source pollution and point source pollution is the problem of information acquisition. If the polluter and discharge can be accurately identified, then the treatment of non-point source pollution will be targeted. Therefore, the mode of "point-source treatment" proposed by the author is actually to improve the monitoring and treatment level of non-point source pollution by strengthening the supervision of fertilization and drug use behavior of China's scattered agricultural production and operation subjects.
Last year, the Implementation Plan for Agricultural Non-point Source Pollution Control, Supervision and Guidance (Trial) jointly issued by the Ministry of Ecology and Environment and the Ministry of Agriculture and Rural Affairs has made it clear that agricultural non-point source pollution in key areas will be under preliminary control by 2025. Prevention and control at source, monitoring level and supervision capacity are all key areas for improvement.
There is still a long way to go for the prevention and control of non-point source pollution. At present, there are various measures for the prevention and control of non-point source pollution in China, but there is still no universal prevention and control scheme. With the strengthening of environmental protection, it is time for the prevention and control of non-point source pollution to form a system!