Potassium nutrition of spring wheat on highly cultivated sod-podzolic light loamy soil

Abstract

The results of studies that, when cultivating spring wheat, made it possible to establish a decrease in the content of available potassium in a highly cultivated soil by 16–26 % in the period from sowing to the flag leaf-heading, due to the consumption of potassium by plants. In the second half of the growing season (heading – full ripeness), the content of available potassium in the soil to a greater extent depended on the moisture content in the 0–20 cm soil layer (η 0,90–0,95). There was an increase in the content of available potassium in the soil by 8–40 mg/kg of soil, free potassium in plants by 0,16–0,68 %, total potassium by 0,04–0,80 %, depending on the phase of growth and development of spring wheat when applying 120 kg/ha of nitrogen fertilizers against the background of P₃₀K₉₀. The effect of potash fertilizers on these indicators has not been established.