Changes in the granulometric composition of Zarafshan river soils under irrigation and comparative analysis

Abstract

According to the granulometric composition of all soil types (typical, light gray, gray-meadow and meadow-alluvial) located on terraces I - II - III of the Zarafshan oasis, it is mainly medium and heavy sand, physical clay (<0.01 mm) and large dust (0.05 – 0.01 mm), medium dust (0.01 – 0.005 mm), fine dust (0.005 – 0.001 mm) and silt particles due to irrigation for many years reduced sand particles and increased the amount of dust and silt particles in all layers of the soil . It is explained by the erosion of feldspar, mica-like substances in the sand particles, the increase of dust and silt particles in the upper layers of the soil as a result of irrigation, and the fact that certain parts are washed to the lower layers of the soil.