Potential of established pastures in the winter rainfall region.
Van Heerden, Johann Myburgh.
MetadataShow full item record
The seasonal production of 11 pastures was evaluated in dryland and irrigated trials at eight sites in the Winter Rainfall Region. These data were related to climatic conditions using the Growth Index concept to produce a model for pasture growth. Under dryland at Tygerhoek, the animal production potential of lucerne and medic was compared in grazing trials. Lucerne was found to be the higher producing of the two. At this site also, the influence of chemical control of volunteer grasses in dryland pastures on animal production potential was tested. Weed control had a positive influence on animal production at low, but not at high stocking rates. Under irrigation at complex grass/legume Tygerhoek, the grazing capacity of a mixture was established under continuous and rotational grazing. While rotationally grazed pastures produced the highest yields, the clover component of these pastures proved to be most productive under continuous grazing. As a result, rotationally grazed pastures, could carry more animals, but animal production was generally highest under continuous grazing. Under irrigation at Outeniqua, seven grass and grass/legume mixtures were compared in grazing trials. Pastures based on fescue generally had the highest grazing capacity, but those based on white clover the highest animal production potential. These data were used to produce a climate:pasture:animal which was validated using independent This model was used to predict animal production model, grazing trial data. performance of two-species mixtures at a number of sites. These results suggested that while grass pastures allowed more animals to be carried than did mixtures, both animal performance and gross returns were highest in grass/legume mixtures.