Influence of lime rate and particle size on soil pH and vegetative and seed yields of subterranean clover in the South East of South Australia

Abstract

The effect of 2 rates (2, 4 t/ha) and 5 particle size grades of applied lime on vegetative and seed yields of subterranean clover on an acid siliceous sand in the South East of South Australia is reported. The movement of the lime down the soil profile was assessed through its effect on soil pH. Vegetative yield responses to lime were recorded in 4 of 5 harvests; there was a significant particle size x rate interaction at 2 harvests. When seed yield was significantly increased by lime application, the particle size treatments were not significantly different. Vegetative and seed yields were not increased by doubling the lime rate. Five years after mixing lime in the top 2.5 cm of soil, there was a significant particle size x rate x depth interaction for soil pH. Soil pH was significantly increased to a depth of 12.5 cm by the application of 4 t/ha of lime, with the finer lime particle sizes causing the greatest increase in soil pH at depth