Recovery of nitrogen by spring barley from ammonium nitrate, urea and sulphur-coated urea as affected by time and method of application

Abstract

The objective of this study was to increase the efficiency of fall-applied N either by placement in bands or by using a slow-release fertilizer. Four field experiments were conducted in north-central Alberta to determine the influence of N source, time of application and method of placement on the recovery of fall-applied N as soil mineral N in May, and on yield and recovery of N in grain of spring-sown barley. The recovery in soil of mineral N by May from the fall-applied fertilizers varied among treatments. More specifically, the recovery was lowest with topdressed application, highest with banding, and tended to be less with incorporation application as compared to banding. Recovery of mineral N was least for sulphur-coated urea (SCU) compared with A.N. and urea, regardless of method of application. The loss of fall-applied N was substantial, but leaching did not go beyond 60 cm deep.