Aggregate properties of a typic ustipsamment under different tillage practices in Maiduguri, Nigeria.

Soil structure is of fundamental significance to the productivity of agricultural soils as it influences their water status, workability, resistance to erosion likewise crop growth and development. The effect of three tillage systems: no-tillage (NT), reduce tillage (RT) and conventional tillage (CT)) on the structural stability of a sandy loam soil in semiarid north eastern Nigeria, was evaluated after 9-15 years of management. At the end of growing season of 2010, triplicate undisturbed core samples (10.8 cm in diameter and 12 cm height) were obtained at two soil depths (0-15 cm and 15-30 cm), screened through a 4 mm mesh, air dried and used for aggregate stability determinations. At the end of the study, aggregate stability of the soil measured as MWDD, MWDW, WSI, DR, and ASC on average was greatest for the NT treatment except MWDD and least for the CT treatment, while the RT treatment recorded intermediary values. Most of the structural stability indices measured were found to strongly correlate with OC, K and TN content of the soil. In general, however, structural stability of the soil decreased with depth irrespective of tillage method. We concluded that, the conservation tillage practices ( NT and RT ) are better soil management options for improving structural stability of the soil, compared to the conventional (CT) treatment.