Soil Humus
Recognizing the important role of humic acids in soil and the general law of storage stability. We will naturally think about how to protect soil humus (HS:husmus). The formation and dynamic balance of soil HS is a complex and
long natural accumulation process. The global soil accumulates 3 trillion tons of carbon, more than the total amount of organic carbon distributed on the surface (2 trillion tons).
They are not only the vitality of the soil itself, but also one of the main sources of CO2. They are “extremely sensitive carbon aggregates for the change of CO2 concentration in the environment and atmosphere”. Which directly affect the carbon balance of the earth’s biosphere. Therefore, the protection of soil HS, is an important problem related to the protection of soil ecology. And even the sustainable development of earth ecology and natural environment.
Soil Ecological protection
1. The extreme condition of the soil loss
However, the soil degradation caused by modern economic development and human activities is not optimistic. The statistics show that in the 1980s, the global soil loss was 25.4 billion tons (4.3 billion tons in China). The desertification soil expanded at the rate of 50 ~ 70 thousand KM2 per year (3436 KM2/ years in China), the lost land 29000 KM2 in 25 years.
Forest decreased at an annual rate of 1%, and the tropical forest decreased by 13 million ha per year. China has reduced the forest by 146 million ha. And led to the laterization of forest soil. Grassland degradation has intensified, especially in China, at a rate of 30 per cent (about 1.3 million ha) per year. With a degradation of 80 million ha till 1999. The frequent occurrence of sandstorms is the bitter fruit of soil environmental deterioration.
2. The essence of the soil loss
Soil loss is essentially the loss of organic matter or humus. Taking the black soil in Northeast China as an example. According to the research of our company, the content of organic matter in the black soil area has decreased from 5-8% in the early stage of development to 1-4% at present.
And the thickness of the black soil layer has decreased from 40~100cm of 50 years ago to 20 – 40 cm today. At present, the loss area of black soil area reach to 27.59 KM2. Which is more than 1/ 4 of its area. And 15% of the parent material is exposed. It is said that Beidacang has degenerated into the second Loess Plateau.
3. Measures taken to soil protection
The destruction of the naturally cultivated soil humus layer may be a few years, a few months. But it takes a long time to recover. For example, forest recovery can take at least decades to hundreds of years, and it takes 300-600 years to restore the soil humus layer 1 cm thick. The task of protecting and repairing soil humus layer is urgent.
Our government has taken a series of strategic decisions to protect the ecological environment. Including returning farmland to forest. Returning farmland to grass, vegetation protection of ecological fragile areas at the source of the Three Rivers and the Northwest Loess Plateau. Promoting rotation, applying scientific fertilization and popularizing humic acid fertilizers. All of which have kept the degradation rate of soil humus, and the soil ecological construction has been achieved initial results.
