Seasonal grazing capacity of an irrigated grass/legume pasture in the Ruens area of the southern Cape.

Abstract

Seasonal changes in grazing capacity of an irrigated grass/legume mixture consisting of lucerne, red clover, white clover, tall fescue, cocksfoot and perennial ryegrass were determined in the Ruens area of the southern Cape. Applying variable stocking rates and three grazing pressures (1, 5; 2, 25; and 3, 0 kg DM/dry sheep-unit/day) in a six-paddock grazing system, it was found that the mean annual stocking rate for maximum wool yield was 54, 4 dry sheep-units/ha over a period of three years. The seasonal grazing capacity of the pasture varied throughout the year and dry matter availability was most limiting during winter and highest during spring. The clover component of the pasture was depressed by the high grazing pressure and declined with age, while the grass content increased proportionally. The proportional lucerne content of the pasture material was more stable and was promoted by the high grazing pressure, but was not influenced by increased pasture age.

Keywords: clover; dry matter; fescue; grasses; grazing capacity; grazing pressure; lucerne; merino sheep; pasture production; perennial ryegrass; red clover; ruens; seasonal changes; south africa; southern cape; stocking rates; tall fescue; white clover; wool production; yield