Cowpea (Vigna unguiculata L. Walp.): A choice crop for sustainability during the climate change periods

Abstract

Climate change is significantly affecting food security and environmental health. The effect is more severe for countries with low adaptive capacity in the developing world. Legumes are among the possible solution for agriculture’s sustainability during the climate change times as they minimize mineral fertilizers use because of symbiotic nitrogen (N) nutrition. Cowpea is a multipurpose legume crop, with combined agronomic, environmental, nutritional, and economic advantages. Cowpea provides dietary protein and serves as a sources of income for millions of rural poor in the developing countries. Cowpea also enhances soil fertility as it contributes huge amount of N through N 2 fixation. Nevertheless, cowpeas productivity remained low in Ethiopia, and there are less awareness regarding the multifold roles the crop can play, its response to climate change and bio-inoculants. Therefore, this review aimed to assess the agro-symbiotic performance, utilization, and climate change response capacity of the crop to exploit its potential toward sustainability. The review result revealed that cowpea performs better than most of the legumes grown in the tropics, achieving acceptable yield performance with limited rainfall of up to 450 mm per annual, and heat stress. Moreover, elevated CO 2 reported to enhance N 2 fixation in cowpea, leading to photosynthesis and seed yield improvement. On the other hand, high temperature and elevated ultraviolet radiation reduced the performance of cowpea crop as these factors inhibits symbiosis. In Ethiopia, mature seed of cowpea, immature pods, and leaves used for food in lowland areas of the country and about 66.5% of Ethiopia’s arable land suits for cowpea production. However, the average yield is limited to 400 kg ha -1 , with annual production and land coverage of 55,600 tons and 69,500 ha, respectively. Overall, this review confirmed the excellent nature of cowpea in terms of climate change response and the diversity of services the crop can offer. From the review, an understanding is captured that Ethiopia has the potentials for raising cowpea productivity having suitable land and agro-ecology. Therefore, introduction of improved varieties, and agronomic practices including bio-inoculants, should be a point of focus to raise cowpea yield, and benefit from the manifold roles the crop can play.