Application Effects of Controlled‐Availability Fertilizer on Dynamics of Soil Solution Composition

Abstract

Abstract The effect of a controlled‐availability fertilizer (CAF) on plant uptake and leaching potential of soil nutrients, in relation to the dynamics of the chemical composition of the soil solution, was evaluated using a pot experiment with three N treatments [CAF or ordinary fertilizer applied as Ca(NO 3 ) 2 and an unfertilized treatment], with or without wheat ( Triticum aestivum L.) plants. Soil solutions were collected nondestructively with looped hollow fiber samplers from the root zone in situ six times during the 49‐d growing period. Wheat plants were also collected at the second, fourth, and last collection date. Concentrations of NO 3 and K in the soil solution were significantly lower for the CAF treatment than for the ordinary fertilizer treatment at all sampling times. Leaching potential of N and K in the CAF treatment was accordingly reduced compared with the ordinary fertilizer treatment, especially at the early stages of plant growth. The concentration of P was low, and not affected significantly by the N treatments, and the leaching potential was negligible. Moreover, plant growth, nutrient uptake of N, P, and K, and their supplying meachanisms in soil were not affected significantly by the N treatments in this experiment. Therefore, the ability of CAF to reduce the leaching potential of soil nutrients without exerting adverse effects on the growth and nutrient uptake of plants was demonstrated for N and K, based on the dynamics of the soil solution composition in the root zone.