Fusuo Zhang, Junfang Niu, Weifeng Zhang
Mar 2, 2010
Citations
9
Influential Citations
139
Citations
Quality indicators
Journal
Plant and Soil
Abstract
Nitrogen (N) over-application is a serious problem in intensive agricultural production areas with consequent large N losses and environmental pollution. In contrast to N, potassium (K) application has been neglected in many developing countries and this has resulted in soil K depletion in agricultural ecosystems and prevented increases in crop yields. Nitrogen-potassium interaction is currently a topic of interest in many studies and the focus of this review is K nutrition under varied N regimes. Nitrogen form and application rate and time influence soil K fixation and release, as well as K uptake, transport, cycling and reutilization within crops. High yielding quality crops can be obtained by optimal N: K nutritional ratios. High rates of applications of N and K do not necessarily lead to increased yield increments and may even reduce yield. Yield response to K uptake depends on N nutritional status and the interaction is usually positive when NO3−-N is supplied. Antagonism between NH4+ and K+ in uptake was mostly attributed to simple competitive effects in the past while evidence showing mixed-noncompetitive interactions existed. Two components of membrane transport systems for K uptake by plants are a high-affinity K+ transport system which is inhibited by NH4+ and a low-affinity K+ transport system which is relatively NH4+ insensitive. Potassium is highly mobile within plants but its flow and partitioning can change depending on the forms of N supply. NH4+ nutrition in comparison to NO3−-supply results in more K translocation to leaves. A better understanding of the mechanism of N-K interaction can be a useful guide to best nutrient management in agricultural practice in order to achieve high yields with high nutrient use efficiency.