Effect of soil properties on the yield and persistence of Mediterranean perennial grasses in southern Western Australia

Abstract

The effect of ten soil types on yield and survival of three perennial grasses, each mixed with volunteer annual species, was studied for three years under periodic grazing. Yields of cocksfoot (Dactylis glomerata cv. Currie), phalaris (Phalaris aquatica cv. Australian) and tall fescue (Festuca arundinacea cv. Melik) were higher on a gravelly yellow podzolic soil than on other types; phalaris also yielded well on a red podzolic soil. Analysis by multiple linear regression showed that the yield of all sown grasses was high when perched water of the A and upper B horizons was recorded early in winter and sustained until late spring. High gravel content in the A horizon improved cocksfoot and fescue yield and depressed that of phalaris. The high gravel content was associated with increased gravel and decreased water retention of the top of the B horizon at 15 bars. Higher texture classes in the A horizon tended to depress yields of cocksfoot and fescue with no apparent effect on phalaris. The higher texture classes of the clay and clay loam soils tended to decrease general root penetrations. Cocksfoot and phalaris were more productive on shallow than on deep A horizon soils, but fescue yield was not affected by this soil property. Yields of the species can be estimated accurately from regression equations based on three or four soil properties. The results suggest options for selecting perennial grasses suitable for specific soil types among the red earth and red and yellow podzolic groups in the South Western Region of Western Australia. The central problem is that cocksfoot, phalaris and fescue can yield well but do not do so on all soil types.