(1) Scientific development of sewage irrigation industrial wastewater has many kinds and complex components. The wastewater discharged from some factories may be harmless, but when it is mixed with the wastewater discharged from other factories, it becomes toxic wastewater.
Therefore, before using wastewater to irrigate farmland, it should be purified according to the standard stipulated in the Water Quality Standard for Irrigation of Farmland, which not only utilizes wastewater, but also avoids soil pollution.
(2) Rational use of pesticides and development of pesticides with high efficiency, low toxicity and low residue should be emphasized. Rational use of pesticides can not only reduce soil pollution, but also eliminate diseases, insects and weeds economically and effectively, and give full play to the positive role of pesticides.
In production, we should not only control the dosage, application scope, application times and application time of chemical pesticides, improve application technology, but also improve pesticide formulations, strictly limit the use of high-toxic and high-residue pesticides, and attach importance to the development and production of low-toxic and low-residue pesticides.
(3) Rational application of chemical fertilizers, increased application of organic fertilizers, formula fertilization according to soil characteristics, climatic conditions and crop growth and development characteristics, and strict control of the scope and dosage of toxic chemical fertilizers. ?
Increasing the amount of organic fertilizer and the content of soil organic matter can enhance the adsorption capacity of soil colloid to heavy metals and pesticides. For example, humic acid can adsorb and dissolve trichlorobenzene herbicides and some pesticides, and humic acid can promote the precipitation of cadmium.
At the same time, increasing organic fertilizer can also improve the flow conditions of soil microorganisms and accelerate the biodegradation process.
(4) Applying chemical improvers and biological improvement measures to apply inhibitors in the soil slightly polluted by heavy metals can transform heavy metals into insoluble compounds and reduce the absorption of crops.
Commonly used inhibitors include lime, alkaline phosphate, carbonate and sulfide. If lime or alkaline furnace ash is applied in acidic and slightly acidic soils polluted by cadmium, active cadmium can be converted into insoluble substances such as carbonate or hydroxide, and the improvement effect is remarkable. ?
Extended data:
First of all, soil protection requires unified planning of agriculture, forestry, animal husbandry and industry, rational utilization and management of soil resources, balance of soil production input and output, adaptation to soil productivity and tolerance, and improvement of soil fertility, soil productivity and environmental landscape. Only by taking biological measures as the fundamental measures and combining with appropriate engineering measures can we achieve the purpose of protecting soil.
The causes of soil pollution are complex, and the main pollution sources include: industrial "three wastes"; Domestic garbage of urban residents; Agricultural chemicals; Livestock and poultry breeding waste, etc.
Harmfulness of soil pollution: After the soil is polluted, the original characteristics will be destroyed and the quality of crops will also decline. In addition, the polluted soil on the surface can easily enter the atmosphere and water body under the action of wind and water, resulting in ecological and environmental problems such as air pollution, surface water pollution and groundwater pollution.
References:
Baidu encyclopedia-soil protection