The influence of species diversity on sward yield and quality.
Abstract
Swards were obtained in 1978-9 by sowing one or more of the following spp.: Agrostis stolonifera, A. tenuis [A. capillaris], Festuca rubra, Holcus lanatus, Lolium perenne, Poa pratensis and Trifolium repens. The populations consisted of a mixture of L. perenne and T. repens and complex mixtures containing all 7 spp. sown by broadcasting to give a random distribution of spp., or in 3 alternative mosaic configurations of discrete colonies. N was applied at 50 or 300 kg/ha year, and swards were cut 5 times/year for 5 years. At 50 kg N/ha year the Lolium/Trifolium swards produced 15% higher DM yield and higher contents and yields of DOM and N than the complex mixtures, effects which were not manifest at the higher N level. It was suggested that the presence of indigenous spp. need not reduce sward productivity below that of swards consisting entirely of improved spp.