Changes in soil enzyme activity, fertility, aggregation and C sequestration mediated by conservation tillage practices and water regime in a maize field

Abstract

We examined the medium-term (3 year) effects of no-tillage, reduced tillage (subsoil-bedding and shred-bedding) and water regime on the soil profile distribution of organic matter and physical and microbiological soil quality indicators in a maize field under subtropical conditions. Soil carbon sequestration was evaluated as well. Residue on the soil surface was about 17–21-fold increased in the no-tillage plots over the mouldboard plough plots, with intermediate increases in the reduced tillage plots. In the surface 0–5 cm, organic matter decreased with increasing tillage and was increased by irrigation. The no-tilled soil had increased values of water-soluble C, dehydrogenase, urease and acid phosphatase activities, aggregate stability and glomalin compared to tilled soils, especially in the shallowest (0–5 cm) layer. The water regime had no effect on soil structural stability or total microbial activity.