THE NUTRITION OF GRAZED PASTURES IN NEW-ZEALAND

Models of nutrient cycles (PKS) in grazed pastures are used to estimat e fertiliser requirements for New Zealand farmers. Work relevant to th e development of these models is reviewed. Fertiliser recommendations should be based on the long-term economic maintenance rate. Short-term modifications based on current soil nutrient status (PS) estimated by either soil tests or dynamic cycling models are probably not justifie d unless current fertiliser use differs greatly from the estimated mai ntenance rate. The effect of maintenance recommendations should be mon itored, and if necessary modified, by soil testing and plant analysis.