Detailed analysis shows that: nitrogen, phosphorus, potassium, iron, tin, aluminum, copper, selenium, sulfur, calcium, carbon, manganese, molybdenum, zinc, boron and so on.
Soil minerals are mineral particles (sand particles, soil particles and colloidal particles) of different sizes formed by weathering of rocks. There are many kinds of soil minerals with complex chemical composition, which directly affect the physical and chemical properties of soil and are an important source of crop nutrients.
Organic matter content is an important index of soil fertility, which is closely combined with minerals. Generally speaking, the content of organic matter in the topsoil of cultivated land only accounts for 0.5-2.5% of the dry weight of soil, and even less below the topsoil, but it plays a great role. People often call the soil rich in organic matter "oily soil". Soil organic matter is divided into fresh organic matter, semi-decomposed organic matter and humus according to its decomposition degree. Humus refers to the black colloidal substance formed by microbial decomposition and transformation of fresh organic matter, which generally accounts for more than 85-90% of the total soil organic matter.