SOME EFFECTS OF SOIL‐WATER CONDITIONS AND SOIL TEMPERATURE ON THE ROOTS OF GRASSES AND CLOVER

Abstract

The effects of soil water conditions and soil temperatures on the growth of grass and clover roots and on the number of new adventitious roots were examined in the field and in glasshouse experiments. Although significantly more new roots were produced when swards were irrigated during extremely dry periods, the effect was small, In general, irrigation appeared to have little effect on the seasonal pattern of production of new roots from the base of the plant. High soil temperatures affected root growth. Branching of roots was increased by high temperatures, but the number of new roots formed at the base of the tillers was decreased, and the mean diameter of the roots was decreased. A multiple regression analysis of the number of new roots beneath a unit area of sward with soil‐water conditions and soil temperatures at the time of sampling gave a significant inverse relationship with soil temperature. No relationship could be demonstrated