Properties and biological activity of rainfed gray soils formed in neogenic slopes in Uzbekistan

Tashkent State Agrarian University, University str., 2, Tashkent province, 100174 Uzbekistan

^* Corresponding author: gulmira_sulton@mail.ru

Abstract

In Uzbekistan, along with gray soils formed in lyoss deposits, reddish soils formed in Neogene deposits are also widespread, which are distributed in mountainous and foothill areas. Reddish soils differ from gray soils formed in lyoss deposits by their appearance, genesis, and properties. The reddish-gray soils formed in the Neogene deposits are widespread in many parts of Uzbekistan and are subject to various levels of erosion. The reddish-brown soils formed in the Neogene deposits are mainly formed in the parent rocks that form a homogeneous lyoss soil, in some places these layers are very shallow and in the strata occur tertiary and calcareous loams, sands and conglomerates. The reddish-gray soils formed in the Neogene deposits are eroded to varying degrees as they are spread on different levels of slope. Erosion damages the fertile layer on the surface of the soil and reduces its fertility. Eroded soils are washed to varying degrees. Under the influence of the erosion process, the amount of humus and nutrients in the soil decreases sharply. Erosion processes adversely affect the mechanical composition, physical, agrochemical properties and biological activity of the soil. As a result, soil fertility decreases. For the soil to be fertile, it is necessary to maintain and increase the amount of humus and nutrients in it.