The difference between humus and soil organic matter
source: time: 2020-10-23
Soil organic matter and humus are not the same. "Humus" refers to a group of independent and differentiated humus, while "soil organic matter" is a substance that degrades underground at different rates.
The humus we collectively refer to mainly includes the following categories:
Fulvic acid: yellow or yellow-brown humus, soluble in water under all pH conditions, and has a small molecular weight.
Humic acid: a dark brown humus that is soluble in water only at high soil pH and has a molecular weight greater than that of fulvic acid.
Black humic acid: Black humus, insoluble in water at any pH value, has a high molecular weight, and has never been found in alkali-extracted liquid humic acid products.
The application of organic matter can effectively activate soil microorganisms. Sandy soil has poor cation exchange capacity and it is difficult to maintain the cation content of nutrients. When drought conditions are widespread and lack of humus, sandy soil cannot hold water. Since water and nutrients are only available for a short time after application, the sand is in a state of "feast or famine".