Observations on the superphosphate requirements of two grazing experiments

Abstract

The superphosphate requirements of the pastures on two existing grazing experiments were examined. The evidence suggested that at high stocking rates a nutrient cycling process may be set up resulting in a lower fertilizer demand by the pastures. In these experiments the greater utilization of pasture at high stocking rates appeared to place no greater stress on the pasture's fertilizer requirement than the standing unused herbage. Consequently, the maximum fertilizer requirement of a pasture may well be the requirement of that pasture in the ungrazed state. Existing knowledge of superphosphate requirements, derived from ungrazed pastures, may therefore define the upper limit of fertilizer need.