Influence of fertiliser and grazing management on North Island moist hill country

Abstract

Abstract A grazing trial was conducted on 99 ha of moist, low-fertility hill country near Woodville, New Zealand, during 1975-1981. Treatments were: low fertiliser (125 kg/ha/a superphosphate (9% P, 10% S)) and high fertiliser (average 630 kg/ha/a superphosphate, plus lime) application rates; and 3 grazing managements — rotational grazing by sheep and by cattle, and set stocking by sheep. Some replication was included in the design, 10 self-contained farmlets being used. Over a 6-year period stocking rate was increased from 6.5 to 12.0 and from 8.8 to 16.1 s.u./ha on low and high fertiliser farmlets respectively. Over this period, and also in the 3 previous years, herbage accumulation was measured, using grazing exclosures and a trim technique. November-April rainfall had a large effect on herbage accumulation rate (HAR) causing year-to-year variation of 23% about mean annual herbage accumulation. The high fertiliser treatment grew 9% more herbage than low fertiliser in the first year after differential a...