Abstract
Appropriate soil management practices are needed in humid tropical south-eastern Nigeria, where high population density and inappropriate and intensive land use cause soil erosion and degradation, and result in declining crop yields. This study was conducted to evaluate the effect of incorporated, surface, and bare (control) residue mulching methods on soil properties and maize growth and yield. Residue mulch was applied at the rate of 6 t ha-1 at the outset of the study. The mulch treatments were arranged as a randomised complete block design with three replicates. The results showed that bulk density was lower in the mulched than the control treatment, and in the incorporated than the surface-mulch treatment. The trend in aggregate stability was similar to bulk density. Sorptivity, transmissivity, infiltration rate at 1 min and 2 h and cumulative infiltration at 2 h were generally higher in plots where residue mulch was incorporated than when it was surface-applied. There was a similar trend in saturated hydraulic conductivity. Similarly, organic matter content and nutrient levels were generally higher with incorporated than with the surface method. Soil moisture content and fractional air space followed the trend in organic matter accumulation. Maize yield was significantly higher in the mulched than the control treatment. Residue mulching resulted in 1.8 t ha-1 higher yield than the control, while the incorporating method produced higher yields than the surface method by 1.9 t ha-1. Incorporating residue mulch may improve soil physical and chemical properties and increase crop production in south-eastern Nigeria.
