Economics of phosphorus fertiliser use on pastures 2. Incorporating the residual effect

Abstract In formulating fertiliser recommendations for phosphorus fertiliser use on New Zealand pastures, it is important to incorporate the residual effect. The Cornforth-Sinclair static model for generating maintenance requirements was extended and a dynamic response model developed. This allowed the implications of different fertiliser strategies to be traced through time. Limited evidence from field trials was analysed to estimate the carryover effect. Further research into this parameter could show a substantial rate of return.