Cocksfoot and lucerne productivity in a Pinus radiata sylvopastoral system: a grazed comparison

PERI P.L; VARELLA A.C; LUCAS R.J.; MOOT D.J.

New Zealand

Congreso; New Zealand Grassland Association Congress; 2001

New Zealand Grassland Association

A grazed comparison of cocksfoot pasture with lucerne was carried out in the Lincoln University Agroforestry Experiment to assess the feasibility of producing high quality pasture under 10 and 11 year-old radiata pine. The level of light intensity under trees was 50-60% of the open (100% transmittance). Sheep liveweight gains (LWG) and grazing days were greater in open pastures than under trees mainly partly because trees had the effect of decreasing the density of the pasture sward and clover content. Sheep performance was superior in lucerne pastures than in cocksfoot pastures for its better nutritive value and apparent intake (189 vs. 115 g/hd/d). LWG per animal in lucerne plots were 220 in open and 158 g/hd/d under trees, and in cocksfoot plots were 132 in open and 100 g/hd/d under trees. Similarly, more LWG per hectare was produced on open pastures (5.1 lucerne vs. 3.4 kg/ha/d cocksfoot) than under trees (2.5 lucerne vs. 1.7 kg/ha/day cocksfoot). Total annual lucerne DM production decreased 36% under moderate tree shade and cocksfoot only 20%. Cocksfoot was more shade tolerant than lucerne during periods when water and temperature were not limiting (September- November). However, when analysing the DM production over all seasons, results showed that lucerne produced 40% more than grass. The mean CP% for cocksfoot plants under trees was 21.3% and 19.6% in open pastures when water was non-limiting. In contrast, tree shade had little effect on lucerne CP%. The relative animal performance in shaded pastures compared to that in full sunlight would determine the more successful species because includes the quantity and quality changes experimented under tree competition (shade, nutrients and soil moisture).