Dynamic aspects of N.P.K. uptake and O2 secretion in relation to the metabolic pathways within the plant roots

Abstract As previously reported1)-4) the inhibition of nutrients uptake by rice plant with such respiration inhibitors as hydrogen sulfide, butyric acid, cyanide, and azide differed strikingly from element to element. The order of suppression, however, was similar in these respiratory inhibitors, and the Ce I Itlon coefficients as revealed in terms of percents of decrease were grouped in the order of K2O·P2O5>SiO2·SO3·Br>MnO·NH4-N·H2O2> MgO·CaO. This established order attracted the authors interest to elucidate the essential mechanism of the uptake of each element, possibly linked specifically with metabolic pathways, particularly of respiration, within the plant roots. In view of the prime importance of three major fertilizer elements N.P.K., the specific metabolic linkages of these three elements were subjected to a energetic study.