The distribution of ryegrass cultivars and other herbage species in respect to environmental heterogeneity within fields

Abstract

Sampling of two fields sown with seeds mixtures includin~ the ryegrass cultivars ‘Grasslands Manawa’ and ‘Grasslands Ruanui’ demonstrated the greater content of Manawa relative to Ruanui on wet as opposed to dry sites, and in tall pasture growing on cattle excreta areas as compared with short pasture growing between excreta areas. Differences of the percentage yield of species other than ryegrass were also demonstrated.

The results are discussed in relation to principles used to determine the composition of seeds mixtures for the establishment of grazed pastures. It is concluded that the environmental heterogeneity of grazed fields confounds application of the principle that the grass species with the highest yield in a given environment should be sown in monoculture in preference to mixture with other grasses.