THE INFLUENCE OF SOIL PROPERTIES AND SOIL AMENDMENTS ON THE SR90 CONTENT OF OATS GROWN IN SELECTED CANADIAN SOILS

Abstract

Oats were grown in the greenhouse in six soils varying widely in pH, organic matter content, C.E.C., per cent saturation, and exchangeable calcium. Sr90 was added to all soils and its concentration in oats, as influenced by soil properties or soil treatment, was determined.The Sr90 content of oats grown in six soils, which included both saturated and unsaturated soils, was highly significantly correlated with the reciprocal of the exchangeable Ca contents of the soils with correlation coefficients of 0.99 for both the straw and the grain. The correlation coefficients between Sr90 concentration and the reciprocal of the C.E.C. for oat straw and oat grain were 0.65 and 0.55 respectively, which were not significant at the 5 per cent level.When calcium salts were added to three acid soils the larger applications of CaCl2 and CaSO4 lowered the soil pH, whereas CaCO3 raised the soil pH, but all three salts caused a decrease in Sr90 concentration in oats. A greater decrease in Sr90 content was effected by the addition of Ca salts to soil with low exchangeable Ca and low percentage Ca saturation than to soil with high percentage Ca saturation. It was concluded that the exchangeable Ca content, not C.E.C. or pH, was the dominant soil property upon which the Sr90 concentration in plants depended.