Seasonal differences in the soil water balance under perennial and annual pastures on an acid Sodosol in southeastern Australia

Abstract

Replacement of native deep-rooted grasses by shallow-rooted ones has resulted in greater losses of water and nitrogen by drainage. To counter this effect we have tested the hypothesis that liming, and the conversion of annual grass pastures to perennial grass pastures, could improve the sustainability of grazing systems in the high rainfall zone (>600 mm per annum) in southeastern Australia, through better use of water and nitrogen. A field experiment consisting of sixteen 0.135 ha (30m × 45m) grazed paddocks representing four pasture combinations (annual pasture (mainly Lolium rigidum) without lime (AP-); annual pasture with lime (AP+); perennial pasture (mainly Phalaris aquatica) without l..