A review of pastoral research carried out on the West Coast of the South Island: 1960-2000

Abstract

The pastoral research carried out on the West Coast of the South Island between 1960 and 2000 could be divided into three categories; nutrient requirements for pasture, pasture establishment and growth and animal performance. Because of the varied fertility of the soil types present, research on nutrient requirement was the largest category. In the 1960's, requirements for pasture establishment and early growth on pakihi (podzol) soils of lime, phosphorus (P), elemental sulphur (S), potassium (K), copper (Cu) and molybdenum were identified. This work was extended to determine P, S and K maintenance requirements of pakihi, recent alluvial and brown terrace soils in the 1970's and 1980's. Elemental S was shown to be the most cost effective S fertiliser under annual rainfall greater than 2000 mm and the tetraphenyl boron (TBK) test was calibrated to measure the supply of nonexchangeable K on recent soils. A series of trials were carried out to determine pasture yield responses to fertiliser nitrogen (N) on recent soils in the early 1970's. Later work in the mid 1980's showed that measurement of accumulated soil and air temperature from early spring did not improve the accuracy in prediction of pasture yield responses to N. On the poorly drained, acid and infertile pakihi soils, the interactions between seed coating and lime were measured and the yield advantages of Maku Lotus and Yorkshire fog as alternative pasture species to ryegrass and white clover demonstrated. Rate of pasture growth trials determined the seasonal pattern of pasture production on a range of sites from 1970 to 1995. On recent soils that could not be moled, gravel moling and hump and hollowing substantially increased pasture production during a spring with high rainfall (2000 mm). In the early 1980's, dairy grazing trials showed that lengthening the grazing rotation during autumn increased winter and spring pasture production. For sheep, preferential grazing of thin ewes from weaning to mating increased overall ovulation rate. The density of sheep dung patches was shown to increase with winter stocking intensity on a pakihi soil. Surveys of dairy farm practice established an association between effectiveness of magnesium (Mg) supplementation of dairy cows and reducing the incidence of metabolic disorders. Many dose response trials established the requirement by dairy calves for selenium (Se), cobalt (Co) and Cu on different West Coast soils. Close contact between West Coast scientists, advisors and farmers ensured that local research information was efficiently communicated with a resulting high level of farmer adoption. Keywords: animal management, fertility, lime, nitrogen, pasture establishment, phosphorus, potassium, soils, South Island, sulphur, trace elements, West Coast