JOHN G. McIVOR

CSIRO Sustainable Ecosystems, Indooroopilly, Queensland, Australia

Abstract

The effects of a range of pasture management options (introduced legumes and grasses, superphosphate, timber treatment, cultivation before sowing and stocking rate) on the amounts of ground cover at the end of the dry season were measured from 1985–1991 at two sites, Hillgrove and Cardigan, near Charters Towers, north-east Queensland. Ground cover levels varied significantly between years and were significantly affected by pasture management. Cover levels were curvilinearly related to pasture yields. Management options which increased pasture growth (tree killing, using sown pastures, applying superphosphate) or decreased pasture consumption (lower stocking rates) increased cover levels. Pasture treatments affected the shape of the relationship between pasture yield and cover. Cover levels were higher for oversown than native pastures at all levels of pasture yield. For pasture yields below 3000 kg/ha, cover levels increased with stocking rate but there was little difference in cover levels between stocking rates at higher pasture yields. The importance of managing stocking rates for the maintenance of ground cover is emphasised.