ACCUMULATION OF 137CS IN SPRING WHEAT AND PERENNIAL GRASSES ON PEATY GLEY SOIL DEPENDING ON POTASSIUM NUTRITION LEVELS

Abstract

On peaty gley soil the authors studied the effect of increasing rates of potassium fertilizers and soil provision with mobile potassium on entry of¹³⁷Cs into grain of spring wheat and hay of perennial grasses. It was established that between the content of mobile potassium in soil and the entry of¹³⁷Cs into products there was a strong inverse relationship (R² = 0,55). The most significant decrease in the transfer factor of¹³⁷Cs into plants was observed in case of increasing soil provision with K₂O in the range of 200-700 mg/kg. On condition of content of P₂O₅ 737-748 mg/kg and K₂O 625-665 mg/kg in soil, the most effective under spring wheat was the use of phosphate and potash fertilizers in R₆₀K₁₂₀ rates, reducing¹³⁷Cs grain intake by an average of 24 %. During cultivation of perennial grasses the maximum reduction of¹³⁷Cs in hay (2.2-3.0 times) was provided by the use of phosphate fertilizers in rates of P₆₀ and potash fertilizers in rates of K₂₄₀. On peaty gley soil, in contrast to the peat-bog soil, the¹³⁷Cs transfer factor into grain of spring wheat was 5 times below the average one; into hay of perennial grasses it was 2 times lower. In addition, in comparison with sod-podzolic sandy loam soil, the parameters of¹³⁷Cs migration into grain of spring wheat were 2 times higher, into hay of perennial grasses the parameters showed similar values.