Management of lucerne for sheep grazing on the Southern Tablelands of New South Wales

Eight whole-farm systems of managing lucerne pasture were compared at one high (near optimum) stocking rate of breeding ewes. These systems were continuous grazing (C), a 2-paddocks (2P), two 3-paddocks (3P), three 6-paddocks and one 12-paddocks rotations. Pasture density, yield and composition were almost solely dependent on spelling time. Maximum lucerne density was maintained when spelling times averaged more than 50 days over the year. Near maximum contributions of annual grasses were achieved when spelling times were less than 45 days. Therefore, to optimize persistence of important pasture components a 'minimum spelling time' policy is suggested. This time ranges approximately from 53 weeks in summer to 8 weeks in winter. Animal production appeared to depend on botanical composition and the extent to which lucerne stem was allowed to develop. Where lucerne failed to persist, or spelling times were long, liveweight gain was low over summer. Thus production was lower on C and 12P respectively, than other systems, and 2P and 3P gave the best overall production.