Comparative root morphology of some pasture grasses and clovers

Abstract

Root systems of three clovers and five pasture grasses grown in sand culture during summer and in soil during winter were examined at two stages of growth.There were large differences in shoot/root ratio between harvests, but no consistent differences among species. In general grasses had longer, thinner, more finely branched roots than clovers, but had similar root surface areas per unit dry weight; grasses also had longer, more frequent root hairs. Of the grasses, Lolium perenne was the most similar to the clovers and Cynosurus cristatus the least similar. Because root hairs of grasses were longer and more frequent, the calculated surface of the root hair cylinder and the volume within the root hair cylinder were several times greater than those of clovers. These differences could give the grasses a strong competitive advantage over the clovers in nutrient and water uptake, especially of immobile nutrients such as phosphate.