SUMMARY
The effects of organic mulching material on soil surface evaporation were studied in Abia State. The objective of the study was to compare impact of mulch materials on saturated hydraulic conductivity and surface evaporation. The organic mulch materials were composted and non-composted Calapogonuim, Chromolena and Panicum spp. The design was randomized complete block design (RCBD). Data generated were statistically analysed. Analysis of variance was used to compare the influence of mulch materials on the measured soil properties and significant means were separated using least significant differences at 5% level of probability. Line graph was used to represent the impact of mulch materials on the surface evaporation. Results showed that saturated hydraulic conductivity of the soils increased significantly (P = 0.05) with the application of the mulch materials. Soil applied with non-composted Chromolena spp. mulch material had the highest saturated hydraulic conductivity (73.00 cm hr-1). Soil surface evaporation varied with both composted and non-composted mulch materials at 3rd and 9th day. The volume of soil moisture lost to the atmosphere was lower in non-composted Calapogonuim mulch material compared with the other mulch materials under study (3rd to 9th day, 3.9 to 11.0 cm3 respectively). Composted and non-composted Panicum mulch was observed to be a more efficient physical barrier to prevent the loss of moisture to the atmosphere as compared to other mulch materials studied. From the present study, it was evident that application of mulch reduced the actual evaporation rates in the initial days after irrigation (coinciding with early periods of plant growth). The water was thus conserved and could be used by the crop subsequently during the later period of its growth.