Increased pollution has led to a large reduction in beneficial bacteria in the soil, soil quality, and weakened self-purification capabilities, affecting the yield and quality of crops, harming human health, and even risking environmental retaliation. First, the ecological relationship is unbalanced, causing the ecological environment to deteriorate. In the major agricultural products surveyed by the Institute of Geographical Sciences and Natural Resources Research of the Chinese Academy of Sciences in the Yangtze River Delta and other places, the pesticide residue exceeded the standard rate of more than 16%, resulting in the continuous reduction of rice field biodiversity and system stability. The second is the decline in soil quality, which reduces crop yield and quality. Chen Zhiqun, a senior agronomist at the National Agricultural Technology Extension Center of the Ministry of Agriculture, believes that due to soil pollution caused by pesticides, fertilizers and industry, my country's grain production is reduced by 10 billion kilograms every year. Third, heavy metal diseases have begun to appear, posing a serious threat to people's health and sustainable agricultural development.
The main causes of groundwater pollution are: industrial wastewater is directly discharged underground, contaminated surface water invades into the underground aquifer, human and animal feces or polluted water due to excessive use of pesticides seeps into the ground. The result of pollution is to increase the content of harmful components such as phenol, chromium, mercury, arsenic, radioactive substances, bacteria, organic matter, etc. in groundwater. Contaminated groundwater is harmful to human health and industrial and agricultural production. Groundwater pollution has the characteristics of slow process, difficult to find and difficult to control. Once groundwater is polluted, even if the source of pollution is completely eliminated, it will take more than ten years, or even decades, to restore the water quality. As for the replacement of artificial aquifers, the problem is complicated.