RESULTS OF THE 70-YEAR RESEARCH AT THE INTERFACE OF FORESTRY AND SOIL SCIENCE

The main results of studying the effect of artificial woody vegetation on chernozem are briefly described in the article, as well as the influence of soil and soil condition on composition and productivity of forest plantations. The effect of soil salinity on plant growth is characterized. The toxicity of different groups of readily soluble salts, especially chlorides and soda, has been evaluated. The decisive role of the depth of toxic amounts of chlorides and the level of water availability in the soil usability has been established. The ecological series of water availability for plants in different soil types have been developed and the degree of suitability of groundwater of different salinity has been evaluated. The power of the root zone as a limiting factor has been estimated, as far as the level of mineral elements supply for plant nutrition (trophicity) in the soil is determined by the greatest total amounts of phosphorus and potassium in the root zone (excluding potassium enclosed in feldspar lattices). All the intrazonal diversity of nature is due to the nutrient status and moisture content in the soil. Along with the warmth level these limiting resources develop one or another level of soil fertility. The role of subsurface runoff in the formation of forest-steppe landscapes is characterized. The stages and phases of the primary soil-forming process are highlighted. It is argued that soil zonality results from bioinert nature of the soil. The article substantiates the statement that soil fertility is a factor ensuring the stability of life on Earth; and the ways of promoting Soil Science at the level of the theoretical basis for agriculture have been proposed.