The benefits and productivity of cereal-legume intercropping with and without supplementary irrigation in the semi-arid highlands of Tigray, Ethiopia

Low soil fertility and limited water availability are the major hampering factors to crop production in the semi arid highlands of Ethiopia. Thus poverty and hunger is evident to the ever increasing population in the country. Comprehensive integration of nitrogen (N)-fixing leguminous species with cereals supported with supplementary irrigation could greatly improve soil fertility, moisture availability and increase livestock feed-base, resulting in food security and improved livelihoods. In line with this, a study was conducted at Mekelle University main campus in the northern highlands of Ethiopia to evaluate the benefits and productivity of cereal-legume intercropping under rainfed conditions and with supplementary irrigation, during the 2015/16 rainfall season. Bread wheat (Triticum aestivum L.) was intercropped with lentil (Lens culinaris Medik) and dekoko (Psium aestivum var. abyssinicum). Results indicated that intercropping increased significantly the grain yield of wheat up to 30.5% under rainfed conditions in wheat-lentil mixture and a noticeable yield increase was also noted in wheat-dekoko intercropping, and supplementary irrigation increased the yields by up to 100%. Higher Land Equivalent Ratio (LER) of 1.83 and 2.38 and LEC (0.82 and 1.34) were registered for wheat-lentil intercropping under rainfed and supplementary irrigation, respectively. Monetary equivalent index (MAI) was also higher (7,937.2 ETBr and 20,642 ETBr) respectively for rainfed and supplementary irrigation in wheat-lentil mixture.