Effects of summer grazing and fertiliser on the clover content of hill country swards in the Gisborne region

Abstract

Preliminary results are presented from an investigation to identify reasons for the low clover content of hill country pastures in the Gisborne-East Coast region. Four experiments were established near Gisbome. Treatments included: fertiliser versus no fertiliser; summer grazing versus no summer grazing; and clover cultivars (transpanted into swards). Summer rainfall had the major influence on the clover content of swards. With a reliable high summer rainfall the clover content averaged 16% of herbage. By contrast, with less reliable and lower summer rainfall, the clover content averaged 4-5% and subterranean clover was more important, Summer spelling of pasture, which allowed rank grass growth, reduced both white and subterranean clover content of swards. Fertiliser inputs increased the clover content of swards. Performance of cultivars was affected by grazing, differences between cultivars being greatest with summer grazing. The small-leaved cultivars of white clover ('Grasslands Tahora' and 'Whatawhata') initially performed better than larger-leaved cultivars at the high summer rainfall site, but failed to sustain any advantage. 'Tallarook' subterranean clover increased the clover content of swards with summer grazing. Keywords white clover, subterranean clover, East Coast, hill country, fertiliser, grazing management