Influence of woody vegetation on the content of humus in chernozem soils

The literature sources on the influence of woody vegetation on the content of humus in chernozem soils were analyzed. In scientific literature, there are many articles from scholars from around the world on the study of the content of organic matter in the soil under various types of plantings. Proceeding from this, there is a need for comprehensive research on humus of reference black soil common. Separately there is the question of the influence of artificial forest plantations of different wood structure and light structure on the complex characteristics of ascending ordinary black soil. The importance of these studies is due to the complex ecological role played by humus in soils. As a result of the analysis of literary data, it was discovered that woody vegetation increases the content of organic matter and positively affects the black soils. Regularities of change in the humus state are connected, first of all, with the type of land use. Under each tree species there is a characteristic and peculiar humus distribution in the soil profile, which differs significantly from the quantitative or qualitative distribution of humus in the soil horizons. In general, under the forest vegetation, the content of humus increases, as well as the structure of the soil improves, the permeability and porosity of the upper layer of soil increases. In the course of the literary analysis it became clear that the older the tree plantations, the greater the thickness of the humus horizon below them. In the monitoring sites under the Tilia cordata, there is a tendency to increase the content of humus, hygroscopic moisture, absorption capacity and granulometric composition, indicating improvement of soil conditions. Plantation of Acer platanoides leads to a decrease in the content of total humus in a 0-30-centimeter layer of soil, but with depth this index is gradually increasing. Under the Quercus robus plantations in the surface layer of soil, scientists observed a decrease in humus content, and in the middle layers of soil, on the contrary, an increase in this indicator. With a depth observed leaching of humus. The indicator of humus under Quercus robus is characterized by a significantly higher level of humus, than in black soil. So, the results are typical for humus in zonal chornozems. The data of some authors show that it is in natural forests that the best conditions for the humus accumulation in black soils are formed in comparison with the soils of artificial forests and soils under zonal vegetation (motley grass, Bromus spp., Stipa spp.). Under forest vegetation, leafy deposits form a litter. The Robinia pseudoacacia litter results in improved physical and chemical properties of soils, increases the content of organic matter, exchangeable potassium, absorption capacity, increases aggregate stability and moisture content, decreases pH and density. Scientific literature notes that the creation of Robinia plantations in soils that have previously lost its forest cover provides an increase in the content and storage of soil organic carbon compared to the Caragana korshinskii plantations. According to our literature data, the most rational measure to increase the soil fertility is the creation of an effective system of protective forest plantations, which are characterized by a favorable integrated influence on the steppe soils.