Evolution of agricultural water management in rainfed crop-livestock systems of the Volta Basin

Abstract

Agricultural water management (AWM) is the activity of planning, developing, distributing and managing the optimum use of water resources for agricultural purposes, through a suite of strategies. This sector comprises all types of agricultural systems, from rainfed to fully irrigated, with water sources varying between rainwater, surface water or groundwater. In the dry areas of the Volta Basin, agricultural systems are mostly rainfed. AWM strategies in rainfed systems are different ways to influence rainwater flows in order to maximize infiltration in the soil, retain run-off and minimize losses, and range from field-scale techniques like stone bunds or manure application to watershed-scale structures like small reservoirs. These AWM strategies have been extensively studied and promoted in the Volta Basin during the last decades. However, economic and physical water scarcity still limits agricultural production of most of the smallholder crop-livestock farms of the basin. Numerous projects and programs are currently working on best-fit AWM identification and promotion in the basin. In this context, there is a high risk of duplication of what has been done or of reinventing the wheel. The objective of this paper is to synthesize existing knowledge, interventions, lessons, and gaps in knowledge regarding AWM in the Volta Basin. The questions that the paper addresses include (i) who did what, how, where, with which results and why, (ii) what are the lessons learned for longer term development efforts and interventions and (iii) what are the knowledge gaps, with focus on the Volta Basin