Effect of superphosphate, lime, and cocksfoot on summer dry hill country pasture production

Abstract

Two long-term field trials were carried out in the Wairarapa. One, established on a resident ryegrass/browntop pasture in 1981, compared the effect of lime (0, 1.25, 2.50 and 5.00 t/ha) and superphosphate (0,125,250 and 500 kg/ha) in a 4 x 4 factorial design. The second, started in 1985, compared the response of a similar pasture with that of au oversowu 'Grasslands Wana' cocksfoot pasture to 4 rates of lime (0, 1.25, 2.5 and 5.0 t/ha). The major effect of the traditional fertiliser policy was increased spring and, under favourable conditions, increased summer and autumn production. The introduction of cocksfoot guaranteed a more predictable summer supply of feed and improved autumn and winter production. An assessment of 3 methods of designating fertiliser expenditure suggests that continuation with maintenance fertiliser inputs, or a 2.3: 1 substitution of fertiliser expenditure for cocksfoot establishment, would provide greater benefits than discontinuing fertiliser inputs. Keywords 'Grasslands Wana', cocksfoot, lime, superphosphate, ferthser, strategies, hill country