Grazing management influences on seasonality and performance of ryegrass and red clover in a mixture

Abstract

Grazing management influences on the production and species composition of a ryegrass, red and white clover pasture were evaluated over 3 years. Pastures were grazed by cattle frequently in either winter or summer and infrequently for the remainder of the year or grazed infrequently all year. Frequency was determined by the height of herbage pre-grazing and was lo-12 cm for frequent grazing and 15-20 cm for infrequent grazing. Annual herbage production of 15.1 t DM/ha was not influenced by grazing management but seasonal production was. Management caused both instantaneous and longer term effects on production of component species. Lower summer production because of frequent grazing in that season resulted from a reduction in red clover production from 2.75 to 1.3 t DM/ha. However, ryegrass production in spring was increased by 60% and in summer it was more than doubled by this grazing treatment. Frequent grazing in winter also increased ryegrass and reduced red clover production in summer compared with infrequent grazing all year but had no effect on ryegrass production in spring. Red clover plant density was unaffected by the different grazing managements imposed for two and a half years but subsequently was lower under frequent summer grazing. Red clover dominance in summer and its effect on ryegrass production in spring can be controlled by more frequent grazing in summer and a more even species balance results. Emphasis on spring or summer production can be achieved through grazing management without affecting total production. Keywords: Red clover, ryegrass, grazing frequency, cattle grazing, herbage production, seasonal production