Some people believe that as long as there is land, they can cultivate it. In fact, this is a misunderstanding. If that were the case, wouldn't every piece of land on Earth be able to grow crops and even produce food?
Soil is not the same as land. It refers to the loose layer on the Earth's land surface where plants can grow. When the surface rocks are subjected to heat expansion and contraction, water dissolution, atmospheric oxidation, and other processes, they gradually decompose and form weathering materials, which become the soil parent material. However, this still cannot meet the needs of plant growth. After the formation of the soil parent material, with the reproduction of microorganisms and plants, nitrogen fixation and the decomposition of organic matter develop, and nitrogen and soil humus continue to accumulate, thus forming true soil.
What kind of soil has high nutritional content? Complex organic compounds formed from dead animals and plants in the soil through microbial action are called "soil organic matter", and the carbon in them is called soil organic carbon. Soil has many nutritional indicators, among which soil organic carbon is a good indicator for judgment. Generally, if there is more organic carbon in the soil, other nutritional elements in the soil will also be more abundant. So when we look at which soils are suitable for farming, we first look at its organic matter. Soils with more organic matter are more suitable for farming. A simple but not entirely reliable method of identification is color - soils with darker colors have richer organic carbon. It's true that the black soil in the Northeast Plain of China is so fertile that you can squeeze oil out of it. But if it's soil polluted by oil, although the soil color is also black, it's not suitable for farming.
Healthy and fertile soils can also "fall ill" for various reasons and become unsuitable for farming. Especially in the process of farming, if pesticides and fertilizers are used improperly, various "harmful" elements that are not conducive to the healthy growth of crops are intentionally or unintentionally added to the soil, which will directly lead to soil pollution and degradation, weakening the production capacity of crops. What should we do if the soil is "sick"? We need to carry out "soil health" activities to enhance the sustainable use of soil. For example, supplementing nutrients to the soil, including organic matter, beneficial microorganisms, and nutritional elements, optimizing soil structure, and creating good conditions for high-yield farming of crops.
To protect the soil, the following measures can be taken: strengthen the management and comprehensive utilization of industrial waste gas, wastewater, and waste residue to prevent the arbitrary discharge of waste containing various pollutants into the soil; rationally apply pesticides and fertilizers, and actively develop high-efficiency, low-toxicity, and low-residue pesticides; treat manure, garbage, and domestic sewage harmlessly; and carefully promote irrigation with sewage. It is best to strictly monitor and control the irrigation of farmland with sewage and use treated sewage for irrigation.