Abstract
In Zimbabwe's smallholder fanning sector, a large proportion of maize (Zea mays L.) is grown on sandy soils which are frequently subject to waterlogging due to restricting layers at shallow depth. A field study of maize root profiles was carried out during the 1992-93 growing season to characterize the distribution and to quantify the length of maize roots in gleyic sandy soils under a tied ridging system compared to conventional mouldboard ploughing. Although the study was limited in scope, the relationship between tillage, relevant soil physical factors, and maize rooting was well defined. The results confirmed that ridging increased soil rooting volume and thus root length per unit volume of the soil, and resulted in significantly higher yields. This was due to the increased and raised topsoil layer created by tied ridging above the generally compact and frequently waterlogged subsoil.
