EFFECTS OF CLIPPING AND NITROGEN ON COMPETITION BETWEEN THREE PASTURE SPECIES

Abstract

In three herbage mixtures comprised of different combinations of orchardgrass, Dactylis glomerata L., creeping red fescue, Festuca rubra L., and common white clover, Trifolium repens L., highest yields of the grasses were obtained when 1) harvesting was delayed until only 2 per cent of the incident light near mid-day penetrated to the base of the sward rather than at 10 per cent penetration, 2) a 2-inch rather than a 4-inch stubble was left after cutting, and 3) nitrogen fertilizer was applied. The same cutting treatments gave maximum yields of the associated clover without nitrogen fertilization, but when nitrogen was applied higher clover yields were obtained when cutting was at 10 per cent light penetration. Yields of the two grasses were approximately the same when grown with clover only, but in the two-grass association orchardgrass held the fescue to a low proportion in the mixture.Results did not support the concept of maintaining a specified minimum leaf area index (LAI) for maximum yield of the herbage mixture.