Abstract:
Sub-soiling/ripping technology for rainwater harvesting was demonstrated to farmers in agro-ecological zones
(AEZs) 4 and 5 in Mwala, Yatta and Kitui districts in eastern Kenya from 2007-2009. Participating farmers
were involved in evaluating the benefits of enhancing soil moisture through use of this technology. The results
showed that sub-soiling/ripping for rain water capture increased maize mean total dry matter (TDM) by 29-
117% compared with conventional tillage. Mean maize grain yields (kg/ha) was increased by 84% in Yatta AEZ
5 and by 38% in Mwala AEZ 4. Yield increases were more for Katumani Composite B (KCB) maize planted in
AEZ 5 than that planted in AEZ 4. The benefits of rain water harvesting through sub-soiling and ripping were
increased when combined with application of 20 kg N plus 20 kg P2O5 /ha at planting in AEZ 5 and 5t/ha FYM
and topdressing with 20 kg N/ha for KCB maize in AEZ 4. Sub-soiling/ripping significantly (p ≤ 0.05) enhanced
soil moisture retention in the 10-30 cm soil depth. Farmers expressed their willingness to adopt the technology,
but indicated the need for the technology to be /modified for enhanced adoption. In terms of yield increase, the
effect of this technology is greater in AEZ 5 than in AEZ 4.
