It can be said that the soil itself is a "natural fertilizer bank". The evolution of plants and even animals is to adapt to the environment and to survive. He absorbs everything the environment can provide, and uses these absorbed "substances" as bones or nutrients to build his own body and form organic life. What substances do plants need to absorb from the outside world? First, the mineral elements in the soil (beneficial and useless will be absorbed), followed by water, and then the carbon dioxide and nitrogen-containing gas in the air (nitrate nitrogen fertilizer is formed by lightning). These "nutrients" are provided by the earth's atmosphere and surface. The most important energy source is the light radiation of the sun. Without sunlight, plants can't synthesize organic matter through photosynthesis, and they can't build organic life. Sunlight is also called "light nutrition" of plants.
Without the sun, I'm afraid the earth is just a dead planet, which is why people usually compare the earth to "mother" and the sun to "father". At present, the only known life-giving planet is Mother Earth, and the sun has been constantly offering invisible "light radiation" energy to the surrounding planets. Having said that, you may understand that there is no birth and reproduction of life without sunlight, and there is no birth and evolution of higher plants without soil and water on the earth's surface. Without plants, there would be no animals and microorganisms, because both animals and microorganisms need plants as a source of nutrition and energy (that is, food). Unhealthy soil seriously damages the vital interests of farmers. Lead to reduced production, or even no production. In recent years, with the rapid development of industry, a lot of waste gas has been wasted. Industrial sewage is discharged into the land. It directly caused soil pollution and heavy metals exceeded the standard. With the extensive use of pesticides, the soil can not be repaired in time. Harmful substances such as bhc in pesticide residues. DDT. Heavy metals, lead, chromium, cadmium, mercury, arsenic, etc. Harmful substances moisten our soil all the time. Causing soil abandonment. Here are some routine items of soil testing. Help farmers understand soil testing. Routine testing, once every 3 years. Collect soil samples after summer harvest or autumn harvest in farmland. Basic test items PH/ cation exchange capacity/key test items/cadmium, chromium, mercury, arsenic, lead, copper and zinc, nickel, bhc and DDT. The test items that affect the yield include total salt content, boron, nitrogen, phosphorus and potassium. Other detection items such as aluminum (acid rain area), iron oxide, manganese, calcium, magnesium, sodium and silicon. And so on, then this kind of project, ordinary agricultural workers can't test it themselves, and these projects can only be tested in testing institutions. Part of the testing fee should be paid. At this time, you need to use agricultural instruments. These items can be detected, and the detection speed is fast. Can guide fertilization. Make up what you lack, don't waste money.
In a word. Bread is the pillar of life. Take care of our land. Make it develop healthily and benefit future generations.