Setting out to Evaluate Rain Water Harvesting (RWH) for Crop production at Botswana College of Agriculture

This report is an account of an on-going study being carried out at Botswana College of Agriculture Farm to characterise soil surface conditions on runoff generation of micro-catchment RWH systems, and to appraise these micro-catchment RWH systems on crop performance. The characterisation undertaking involved a replicated runoff yield trial of two factors: size of catchment at three levels (5 x 5m, 5 x 10m and 5 x 20m) and four common soil surface conditions [ploughed surface (PS), harrowed surface (HS), managed crop (PM) and natural vegetation (NV)]. Trenching (for the installation of the runoff collection system at the bottom of each plot) was carried out. The appraisal of micro-catchment RWH systems on crop performance involved a replicated trial of two factors: catchment size at three levels and tillage treatment. Measurement of maize growth parameters and installation of runoff collection system which commenced in March 2012 were halted in mid-April 2012 due to an abrupt end of the rain season. No significant rain had fallen to initiate surface runoff for quantification. The study continues.