What does organic matter of organic fertilizer mean? Is the higher the better?

Organic matter is an index to measure organic fertilizer, not the higher the better.

Carbon is expressed in soil, that is, in organic matter. At present, the organic matter of cultivated land in China is generally low, with an average of about 1%. Raising the land with organic fertilizer greatly increases the carbon content of the soil, thus increasing the yield. Organic fertilizer here refers to all photosynthetic products and their derivatives in nature, not just human manure and animal manure in the traditional understanding. Organic fertilizers in efficient ecological agriculture will mainly be plant-derived fertilizers such as green manure, straw manure and weed manure.

Our experimental data show that when the organic matter of ecological farmland increases to 5% in warm temperate humid areas, even the crop yield of blank control (without fertilization) can exceed the annual output of wheat and corn.

Soil organic matter refers to all kinds of animal and plant residues that died in different decomposition stages in the soil, and it can also be said to be various forms of carbon-containing organic compounds in the soil. It is an important part of soil and an important index to measure soil fertility. In general cultivated land, the content of organic matter in the surface soil only accounts for 0.5% ~ 2.5% of the dry weight of the soil, and even less below the surface. People often refer to the soil with more organic matter as "oil soil".

Soil organic matter can be 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. The content of soil organic matter in most parts of China is relatively low, which can reach 2.5% ~ 7.5% except the black soil area in Northeast China. For example, most areas in North China and Northwest China are below 1%, while paddy fields in Central China and South China are slightly higher, reaching 1.5% ~ 3.5%.