Pore Size and Bulk Density as Mechanical Soil Factors Impeding Root Development

Abstract

Measurements of pore size and bulk density for seven clay soils are reported in this paper as related to observations on root development under field conditions of Para, Guinea, and Bermuda grasses. The combined effects of high bulk density and predominantly small pores apparently reduce root development in Para and Bermuda. Guinea grass, a dryland forage, is able to send roots through relatively dense soil horizons with high microporosity. This might explain, at least in part, the drought tolerance of this grass.