Loss of Fertilizer N from Plants-soil System and the Strategies and Techniques for Its Reduction

Abstract

The present paper summarizes the studies conducted in China relevant to the improvement in the efficiency of fertilizer N by reducing N losses from crop plant-soil systems. It includes those topics such as the extent, pathways and mechanisms of fertilizer N losses from soil-plant systems, the agronomic efficiency of fertilizer N and the environmental impact of N loss, and the principles and techniques for reducing N loss and improving N efficiency. The efficacy of optimization of the rate and timing of N application, deep placement, irrigation-fertilization, urease inhibitors, nitrification inhibitors, and surface film for reducing ammonia loss from flooded rice fields are thoroughly discussed.