A comparison of the effects of autumn deferment and continous grazing on the growth of an annual pasture

Abstract

The effects of deferred autumn grazing on a pasture comprising nearly equal proportions of subterranean clover (Trifolium subterraneum), capeweed (Arctotheca calendula) and annual grasses were measured over two growing seasons. Autumn deferment increased the survival of capeweed seedlings in both years and of clover in one year but had little effect on the annual grasses. Although there was more herbage present on the deferred plots in early winter, under later set stocking at normal levels by spring the amount of herbage present, plant density, botanical composition and seed numbers were similar on all plots. The accumulation of herbage under deferred grazing caused an elevation of shoot apex height in capeweed, but not in clover. When combined with subsequent intensive grazing, the number of capeweed plants surviving to flowering was sharply reduced. However, this management also resulted in a reduction in herbage production in spring.