I. Pasture production and botanical composition

Abstract

Effects of superphosphate, lime, and stocking rate on pasture production were studied over a 5‐year period on a central yellow‐grey earth on the Wairarapa Plains at the Masterton Field Research Area. A high annual rate of superphosphate (500 kg/ha) did not increase pasture production above that obtained from a low annual rate (125 kg/ha), but lime (6300 kg/ha) increased pasture production. A high stocking rate (22 ewes/ha) decreased pasture production in 2 years. Point analysis of botanical composition showed that browntop ( Agrostis tenuis Sibth.) cover increased to a maximum in the third year and then declined. Both the high rate of superphosphate and the lime significantly reduced browntop cover. Ryegrass ( Lolium × hybridum Hausskn.) and white clover ( Trifolium repens L.) cover increased linearly with time, the spring recordings being significantly correlated with the previous summer's rainfall.