Competitive adaptation by plants to nutrient shortage through modification of root growth and surface charge

Plants respond to lowering Nand P nutrition by increasing their relative root growth (lowering S:R ratio) and decreasing their root cation exchange capacity (CEC); the 2 responses were correlated. The smaller the normal CEC of the plant the greater these changes were. Part of the competitive advantage of low CEC plants may lie in their greater increase in relative root growth in response to limiting concentrations of phosphate.