DIFFERENCES IN NITROGEN AND MINERAL CONTENTS IN THE KERNELS OF CEREALS, BUCKWHEATS AND PULSES

We investigated chemical composition of cereals (rice, foxtail millet, barnyard millet, proso millet, sorghum for food, sorghum for feed, Job's tears, wheat, barley), buckwheat (common buckwheat) and pulses (small red bean, kidney bean, soybean). Kjeldahl-digested materials of powdered whole kernels of 719 samples were analyzed by automated colorimetric procedure (Technicon auto-analyzer) for N and P contents. HCl solution (0.34N) extracts of powdered whole kernels of 719 samples were analyzed by Polarized-Zeeman atomic absorption spectrophotometry (HITACHI Z8000) for K, Mg, Ca and Mn contents. Most of the cereals for food (including buckwheat) which have a history of more than a thousand years in East Asia showed about 1.5 of Mg/K ratio in chemical equivalence. Wheat, barley and sorghum (for animal feeding) which originated from West Asia or Africa showed comparatively lower Mg/K ratio. Pulses had the lowest Mg/K ratio, i.e. approximately 0.4, because of high K content. These data suggest that the contents and balances of K and Mg in crop kernels are genetically controlled.