Author:
Okunade D A,Adekalu K O,Gowing J W
Abstract
Abstract
Field experiments were conducted at the Teaching and Research Farms, Obafemi Awolowo University, Ile-Ife in a completely randomized design with five soil-water conservation (SWC) treatments: Contour bunds (CT); Infiltration pits (IP); Mulched plots (ML); Tied ridges (TR); and the Conventional practice (CP), which served as the control. Four (4) levels of soil moisture replenishment [50% (Full Replenishment), 25% (½), 12.5 % (¼), and 6.25 % (1/8)] after depletion to 50% of Field Capacity (FC) were considered as supplementary water application from an in-situ RWH system. Measurements of soil moisture in the soil profile, plant growth parameters and yield at harvest were made. Results showed that maize yield and WUE varied amongst the SWC practices and within the years from the experimental plots with substantial yield improvements. The TR and CT gave better yields compared with the ML and IP of the same year. The 50 and 25% replenishment levels under TR and CT also gave better yield and WUE compared with other levels of replenishment. Biomass yield for the 2008-2010 planting seasons recorded higher values in TR, IP and CT compare to the control experiment, while the moisture retention ability was better in TR and slightly lower in CT of the same year. In 2011 soil moisture replenishment, the 50% gave the highest yield in a TR, followed by the CT and ML treatments. The TR gave the best WUE for the 50% and in all cases the CP gave a comparatively low efficiency. The study concluded that the methods of soil moisture conservation practice is an effective way to increase water availability for higher crop yields; but a combination of the supplementary, in-situ RWH system could produce better results in terms of enhanced yield and mitigate against the adverse effect of short duration intra-seasonal drought.