Influence of site conditions on interspecific interactions and yield of grass- legume mixtures

摘要

Composition and yield of mixtures including fast- and slow-growing grasses (Lolium perenne and Dactylis glomerata) and fast- and slow-growing legumes (Trifolium pratense and Trifolium repens) at two sowing densities were explored over three years. Results are presented from two sites in southern Germany with different environmental conditions but similar management. The investigation is part of COST action 852 Working Group 2. Due to interspecific interactions the botanical composition of the mixtures altered. The proportion of legumes declined, D. glomerata became more and more competitive, and T. pratense showed the lowest persistence. These results were obtained at both sites, only the rate of change being different. At four cuts per year the mixtures achieved yields up to 17 Mg DM ha~(-1) at site I and up to 15 Mg DM ha~(-1) at site II. The fast-growing species produced the highest yields in the first and second year, while D. glomerata was more productive afterwards.