INFLUENCE OF K AND CS ON RELEASE OF CS 137 FROM THREE SOILS

Abstract

Experiments were conducted to study the influence of stable K and Cs amendments on the uptake of Cs/sup 137/ by Ladino clover upon prolonged cropping of contaminated soils. The addition of K to soils containing relatively high levels of K was ineffective in reducing Cs/sup 137/ uptake by plants but after the soil K was reduced to a low level by cropping, the addition of K to soils reduced Cs/sup 137/ uptake by plants. This implies that K added to a soil may reduce Cs/sup 137/ uptake by plants when the soil is low in K content but not when high in K. The Cs/sup 137 uptake by plants increased as the K concentration in the soil was reduced by cropping. The addition of small amounts of Cs to the soil markedly increased Cs/sup 137/ uptake by plants and reduced K uptake. The addition of Cs even at a level severely injurious to plants increased Cs/sup 137/ uptake rather than reduced it. The threshold level for producing injury to clover appeared to be around 4.5 x 10/sup -4/ me Cs per g soil in Vina loam. The toxic effect of Cs added in injurious amount to the soil was alleviatedmore » by the addition of K. K was, thus, antagonistic to Cs. The amount of Cs and K uptake by plants depended on the soil type. Uptake of Cs/sup 137/ by plants was in the order Hanford> Adken> Vina, and, concurrently, K uptake was in the reverse order. (auth)« less