GROWTH OF SHEEPS-BURNET AND 2 DRYLAND LEGUMES UNDER PERIODIC MOB-STOCKING WITH SHEEP

Growth of established pure and mixed swards of sheep's burnet (Sanguis orba minor ssp. muricata), birdsfoot trefoii (Lotus corniculatus L.), and lucerne (Medicago sativa L.) was investigated under periodic sheep -grazing for 19 months in the lower Not-th Island. Swards were 16 mont hs at the start of grazing and consisted of 34-73% weeds (mainly peren nial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L .)). Seven grazings (leaving 2-4 cm stubble) were undertaken, each wit h 150 sheep for 3 days. Net herbage accumulation of all swards (sown s pecies + weeds) averaged 9.7 t DM/ha per year with highest and lowest estimates in the spring (50 kg DM/ha per day) and late autumn/winter ( 11 kg DM/ha per day), respectively. Mean sward content of sown species varied from 5% (winter) to 70% (summer/autumn). Most variation in thi s study was attributable to season rather than to differences between swards within harvests. The content of sown species often declined ove r the study period with that of sheep's burnet declining 20-60% in one year. The data suggested that sheep's burnet, birdsfoot trefoil, and lucerne were not persistent and therefore that their most appropriate roles were as short-term (less than 3 years) forages.