Establishment of Perennial Forages II. Subsequent Root Development1

Abstract

AbstractThe effect of interspecies competition during establishment of three perennial forage grasses and three perennial legume species on subsequent root development was investigated in two similar field experiments.Interspecies competition had a greater effect on the upper 15‐cm root yield of the legume and upper 10‐cm root‐rhizome yield of the grass species than on forage yields.During the year after seeding, when fertility and moisture were limiting factors, lowest carbohydrate levels occurred in weeded swards with heavier root weights (g/m2). Highest carbohydrate levels in unweeded treatments probably resulted because a low quantity of minerals and water was supplied by the smaller root systems, which limited growth and resulted in carbohydrate accumulation. When moisture and fertility were adequate, little difference existed in carbohydrate levels among treatments, although large differences existed in root weights. This observation can explain the more pronounced treatment effects on forage yields that were observed when moisture and fertility were low.