Effect of stocking rate and fertilizer on the performance of steers grazing Townsville stylo-based pasture in north Queensland

Abstract

The performance of steers grazing Townsville stylo (Stylosanthes humilis)-native grass pasture, with and without superphosphate fertilizer, was studied at two stocking rate (0.41 and 0.82 beasts ha-1) on the sub-coastal spear grass region of the dry tropics of north Queensland over a period of three and a half years. Fertilizer increased yield and quality of pasture, but invasion of the fertilized areas by annual grass species was occurring by the end of the study. Liveweight gains on fertilized Townsville stylo pastures were greater than on unfertilized Townsville stylo, where performance was similar to that recorded on untreated native pasture at stocking rates of 0.25 and 0.41 beasts ha-1. Liveweight gains at the lighter stocking rate were greater than at the higher level on the Townsville stylo-native grass pasture, but at the stocking rates applied to native pasture there was no significant effect of stocking rate. A stocking rate of 0.41 beast ha-1 on fertilized Townsville stylo was safe in all years. Wastage of material was high owing to mould development on the Townsville stylo which remained as standing hay during the winter.