Changes of Nutritive Elements in Soils That Medium-Supplied With Phosphorus, Depending on Fertilizers Used in Cotton Agrocenosis

Abstract

The aim is to increase the mobile nutrient content in the soil by applying optimal nitrogen and potassium fertilizers without the use of phosphorus fertilizers on irrigated typical gray soils moderately supplied with mobile phosphorus. Significant differences are observed in the amount of mobile phosphorus in the soil from the beginning and till the end of the vegetation. It ranged between 24.28-27.15 mg / kg in the driving layer and between 15.20-19.05 mg / kg in the sub-driving layer. The amount of N-NO3 increased during the vegetation to 29.1-34.4 mg / kg in the driving layer, N-NH4 in the driving layer changed to 3.1-4.2 mg / kg. Exchangeable potassium was found to fluctuate between 148.72–177.82 mg / kg in the driving layer at the end of the vegetation period and varied between 179.2–182.75 mg / kg in the sub-driving layer.