Influence of soil type on Heteropogon contortus-Bothriochloa bladhii dominant native pasture in south-eastern Queensland

Abstract

The effects of soil type on presentation dry matter yields and nutrient concentrations of a native pasture in south-eastern Queensland were investigated within a 160 ha area over 5 years. The soil types ranged from a shallow sand (Ug 2.12; Northcote 1971 classification) to deep self-mulching clays (Ug 5.15). Soil type had a major influence on above-ground yield (range 2700-8700 kg/ha), but a limited influence on root yield at 15 cm (range 3200-3800 kg/ha) and on nutrient concentrations of above-ground matter and of roots, (ranges for tops and roots: nitrogen 0.51-0.63 and 0.83-1.22%, phosphorus 0.09-0.14 and 0.08-0.10%, potassium 0.40-056 and 0.23-0.46%, and sulfur 0.05 and 0.05-0.06%). This suggests that soil type has only a limited effect on the liveweight gains per animal which can be attained on native pasture, but a major effect on sustainable stocking rate.