| Abstract: | Abstract The effects of Ca and K levels on barley (cv. Johnston) yield were studied in soil media containing high levels of Mg. The dry matter yield of barley decreased with increasing concentrations of Mg in soils, but the decrease was small. Dry matter yield was positively related to concentration of K in the soil. However, additions of fertilizer Ca or K did not increase dry matter yield, indicating that depressed yield associated with high Mg levels was not due to reduced availability of Ca or K. In commercial agriculture, applications of either Ca or K to such soils are unlikely to prove beneficial in increasing crop yields. Concentrations of Mg in soil solutions of unfertilized soils were lower than levels which were previously shown to reduce crop yield. Additions of N fertilizer increased Mg concentrations to levels which could reduce barley yield |
