The role of indigenous knowledge and water harvesting in sustainable agricultural systems in Tigrai, Ethiopia

The objectives of this study were to evaluate the environmental and socio-economic impacts of small-scale water harvesting projects in the highland agro-ecozone of Tigrai, Northern Ethiopia, specifically the CIDA-funded Water Harvesting Institutional Strengthening Tigrai (WHIST) project of the Prairie Farm Rehabilitation Administration's (PFRA). A second objective was to evaluate the farmers' indigenous knowledge (IK) in relation to land management and project development. Farmers' IK of their land includes local descriptive terms for soil, based on colour, topographic occurrence, fertility, tilth and crop suitability. Farmers rely on their IK to make decisions about land use and cropping. Farmers consider that soil quality declines with increasing cultivation and is mainly a consequence of the removal of nearly all crop residues. Government policies related to land ownership are important factors influencing conservation and sustainability, and policies that establish long-term rights to land by farmers are needed. The IK of soil quality and land relates well to scientific knowledge and provides an opportunity for researchers, extension workers and project developers to establish effective communication with farmers, and can supplement the scarce scientific data. Combining the IK and scientific knowledge (SK) may improve the success and productivity water harvesting and other development projects in the region. Qualitative information from household surveys supplements the quantitative information obtained through scientific studies and they should be incorporated in future studies. Smallholder farmers and their households have benefited from the WHIST projects (micro-dams and river diversion systems, on-farm reservoirs and shallow wells) in terms of reducing farming risks, improving yields of marketable crops, and developing improved markets. Successful irrigators became more food-secure and their income increased compared to non- irrigators. Despite their positive contribution, many water projects failed to achieve their objectives because of water loss through seepage and evaporation, inappropriate water application strategies, and lack of knowledge of soils and topography in the catchment areas. Poorly placed on farm reservoirs (OFRs) often occupy the most productive farmlands. Inadequate preliminary studies by project developers and the exclusion of fanners and their IK from decision making during construction and management resulted in the poor designs of many projects. It is critical that farmers be included at all stages of project development in order to improve environmental sustainability, achieve economic growth, and to enhance contributions to food security