THE EFFECT OF POTASSIUM FERTILIZATION ON THE Sr90 CONTENT OF CROPS

Abstract

Three soils were used in greenhouse experiments to determine the effect of KCl and K2CO3 on the Sr90 concentration in oats, alfalfa, and timothy. In addition soils were moist incubated to determine the effects of similar potassium treatments on water soluble Sr90, calcium, and potassium.The general trend of results found in the greenhouse experiments was that increasing levels of added potassium caused decreases in calcium, magnesium, and Sr90 contents and increases in potassium contents of the crops. The decreases of Sr90 were frequently greater when potassium was applied as the carbonate compared with its addition as the chloride. There were some exceptions to these trends. For instance, Sr90 concentrations in oat grain increased with the addition of KCl to two of the soils. Increases in Sr90 content were also found for timothy grown in one of the soils when KCl was applied.The greater apparent effectiveness of K2CO3 in reducing Sr90 content of crops compared with the addition of the chloride is explained in part by the results of incubation experiments, where KCl caused increases in water soluble Sr90 whereas K2CO3 caused either smaller increases or decreases.