Agrochemical properties of alluvial soils of Insar river flood

Abstract

Studies show that the most fertile are the granular soils of the Central floodplain of the Insar river. They have high humus content in the upper horizons – 4.6-7.6 %. Down the profile, the humus content gradually decreases, but remains relatively high: at a depth of 60-70 cm – 4.0 %. The humus content in alluvial granular-layered and meadow-marsh soils is much lower. The active reaction of these soils is neutral or slightly acidic, since the river and groundwater of the Insar floodplain are medium mineralized and belong to the class of bicarbonate. The hydrolytic acidity of the alluvial granular soil of the Insar floodplain is 1.6-3.0 mg / 100 g of soil. The values of hydrolytic acidity of alluvial granular-layered and meadow-marsh soils are higher: 2.6-3.6 and 1.8–3.2 mg/100 g of soil, respectively. The studied alluvial soils are almost completely saturated with bases: 91-97 %. The studied alluvial granular soils of the Insar floodplain are characterized by an average content of available phosphorus. In granular-layered and meadow-marsh soils, the amount of this element is slightly less and is 7.0–5.1 and 7.4–5.4 mg/100 g of soil, respectively. The most potassium-rich alluvial granular soil in the floodplain of the Insar river, where the content of this element in the upper layers is characterized as high: 16.5–27.6 mg/100 g of soil. In the sod layer of granular-layered soil, potassium availability is average: 9.5-15.4 mg / 100 g of soil. In the turf layer of meadow-marsh soils, potassium content is observed for most crops (8.0-10.4 mg / 100 g of soil), with depth it decreases.