Conditions and factors of humus formation in soils of mountain and foothill

On the basis of information on the climatic factor, the intensity of humus formation in the soil was estimated. It was revealed that as the transition from the plain to the foothills and low mountains due to changes in atmospheric precipitation and hydrothermal regime, the period of biological activity (PBA) of the soil increases from the plain to the mountains. The balance of annual radiation in the foothill plain is 47 kcal/cm2, in the high-mountain belt - 53 kcal/cm 2 . As the transition from the plain to the mountainous part of the relief, an increase in soil PBA was revealed and, in accordance with this, the content and reserves of humus, as well as labile humic substances in the humus composition, increase. By the type of humus, light gray soils are humate-fulvate and fulvate; typical, dark gray soils and mountain brown soils, fulvate-humate; light brown meadow-steppe soils, and humate. It also provides information on the energy reserves of humus for the considered soils. The correlations between the indicators of PBA and humus for horizon “A” in the studied soils were calculated.