Effects of soil management practice on soil physical conditions affecting root growth

Cultivation and drainage are two major management techniques used to modify soil physical conditions for crop growth. In England and Europe ploughing increased the volume of macropores (pores of diameter >50 μm) but markedly reduced their continuity between topsoil and subsoil compared with direct drilling using a triple disc drill. In Australia, during the first year after pasture, tine cultivation to 100 mm had no greater adverse effect on pore continuity than had direct drilling using a tine drill. The importance of macropores for effective land drainage was evident from the reduced efficiency of mole channels in the presence of a cultivation pan. Root growth and activity were related to the volume of macropores but were impaired when the continuity of those pores was reduced or, as in undrained land, they became water-filled.