IN ESTABLISHMENT AND MAINTENANCE OF MIXED SWARDS

Most of the world’s humid grasslands consist of mixed species swards which are harvested by grazing animals. Managing mixed swards to maintain the desired species is often difficult as perennial pastures tend toward biologically diverse communities over time, a result of genetic shifts in populations, competition, grazing frequency and intensity, and the environmental stress factors, temperature, water, soil fertility, pH, and pests. Maintaining legumes in mixed swards is a problem since cultivars of most species are ill suited for pasture and generally are short-lived, necessitating frequent replanting. Since grasslands are extremely dynamic and responsive to environmental stress, various management strategies are used to deal with the problems of mixed species swards. These include controlled grazing methods, growing and grazing different species as monocultures, fodder tree legumes with grasses, or simply grazing a grass-N monoculture. New approaches are needed in forage improvement where selection is done on the basis of method of utilization and general growth environment to improve tolerance to grazing, competition, unfavorable soil conditions, and pests.

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