The Effect of In-Field Rain Water Harvesting on Orange-Fleshed Sweet Potato Biomass and Yield

Abstract

Water scarcity affects both food security and human nutrition. In-field rain water harvesting (IRWH) combines the advantages of rainwater harvesting, no-till, basin tillage and mulching on high drought risk clay soils. In this study, the IRWH system was customized to fit the cropping system of orange-fleshed sweet potato (OFSP). Field trials were conducted over two seasons to compare cultivation of OFSP using IRWH versus conventional tillage (CON). Data collection included plant survival, root initiation, marketable root yield, unmarketable root yield classes and biomass. Planting OFSP using the IRWH system resulted in significantly higher total biomass, higher marketable and total root yield per plant, as well as larger number of roots per plant compared to CON. Despite the relatively higher yield, total production (t/ha) was only significantly higher in season two at 4.6 t/ha vs 2.7 t/ha for CON. Subsistence farmers and households in semi-arid areas may grow small plots of orange-fleshed sweet potato in IRWH opposed to only growing maize and in that way add vitamin A to the diet. This is the first study on the application of IRWH to produce OFSP under rainfed conditions, and more research can be conducted to expand the knowledge on application and benefits of IRWH for OFSP production.