Interactions among ammonium, potassium, and calcium during their uptake by excised rice roots1

Abstract

Abstract The interactions among NH4, K, and Ca during uptake by excised rice (Oryza sativa L. cv. ‘Nova 66') roots were studied under aerobic and anaerobic conditions. In solutions containing either NH4 or K at concentrations ranging from 10‐6 to 10‐3 M, the uptake of both NH4 or K increased with increasing additions of Ca under aerobic conditions. Similar effects of Ca on NH4 and K uptake also occurred under anaerobic conditions. However, the magnitude of uptake under anaerobic conditions as compared with aerobic conditions was about 80 and 15%, respectively, for NH4 and K. The uptake of K decreased markedly with increasing concentrations of NH, in the uptake solution, while the uptake of NH4 was affected little by the concentration of K in the uptake solution.