Abstract Water is a valuable resource for rice production, which is an integral component of food security in East Africa (EA). Rice farming is expanding in the region, with up to 90% produced on smallholder farms using traditional flooding and rain-fed methods, vulnerable to climate change and variability. Despite EA's enormous agricultural and crop potential, the region largely depends on rice imports (> 500,000 tons annually) from Asia due to rising gaps between production and consumption. Sustainable water management practices, including alternate wetting and drying (AWD), system of rice intensification (SRI), and drip irrigation are critical for paddy and upland rice production although practiced at micro-research levels with limited adoption of such technologies by smallholder farmers. Herein, we synthesize key information on smallholder irrigation agriculture development and implications for food security in changing climates in the four EA countries (Uganda, Kenya, Tanzania and Ethiopia), based on scientific literature and reports. Several studies indicate water scarcity is a major threat to rice production, while poverty and food insecurity are linked to low agricultural productivity. Although rice production has increased since 2000 because of the slight expansion of irrigation, yields are still low due to insufficient irrigation development, climate change, and variability and poor agronomic practices. Nonetheless, climate-smart water management technologies such as AWD, SRI, and drip irrigation are less used by paddy and upland rice smallholder farmers for several reasons including limited awareness, funding, and technical knowledge. Therefore, commitments of government sectors, NGOs, farmer-based organizations, and private sectors with clear policies are needed to enhance technology transfer, action research, farmer training, and innovation development. These actions are vital to promote knowledge generation and the adoption of technologies to improve water management for increased rice yields, livelihoods, and food security in changing climates.

Regions affected by resource scarcity, poverty, and land-use conflicts need to advocate the merits of practices strongly grounded in sustainable land management. This review paper provides an analysis of agroforestry as an integrated system embedded in complex relations between resource uses in the Water–Energy–Land–Food (WELF) nexus. Using the African Sahel region as a case study, the paper explains the need for understanding land management practices, such as agroforestry, through the lens of trade-offs and benefits inherent in the WELF nexus. Agroforestry practices are demonstrated to be valuable interventions leading to i) resilience to climate stresses, ii) water, energy, and food securities, iii) mitigation of resource-oriented harbingers of conflicts and iv) development opportunities. These goals can also yield valuable results in terms of promoting sustainable development, i.e. functional ecosystems, livelihoods, and human security. Two overarching sub-nexuses, namely agroforestry–food–energy and agroforestry–food–water–climate, are identified in the Sahelian context and conceptualized. Primarily, the trade-offs outlined within these sub-nexuses are fuelwood vs. crops, use of land for more forests vs. more cropping, and water availability for agroforestry vs. agroforestry impacts on the water cycle. Despite the positive outcomes and opportunities, agroforestry systems in the Sahel still face some challenges such as vague land use rights, inadequate capacities and lack of investments. Policy recommendations are synthesized at three levels. This synthesis involves remedies to lessen pressures at the interlinks of WELF resource use, overarching remedies in the two sub-nexuses, and remedies across all the sectors and issues for improving agroforestry outcomes. Optimal remedies stress the importance of choosing the right land, water and plant combinations as well as incorporating efficiency measures and alternative sources. A successful agroforestry system is characterized by a conducive environment at the farm level in terms of institutions, management, enhancing the farmer's capacity, and good infrastructure.

Regions affected by resource scarcity, poverty, and land-use conflicts need to advocate the merits of practices strongly grounded in sustainable land management. This review paper provides an analysis of agroforestry as an integrated system embedded in complex relations between resource uses in the Water–Energy–Land–Food (WELF) nexus. Using the African Sahel region as a case study, the paper explains the need for understanding land management practices, such as agroforestry, through the lens of trade-offs and benefits inherent in the WELF nexus. Agroforestry practices are demonstrated to be valuable interventions leading to i) resilience to climate stresses, ii) water, energy, and food securities, iii) mitigation of resource-oriented harbingers of conflicts and iv) development opportunities. These goals can also yield valuable results in terms of promoting sustainable development, i.e. functional ecosystems, livelihoods, and human security. Two overarching sub-nexuses, namely agroforestry–food–energy and agroforestry–food–water–climate, are identified in the Sahelian context and conceptualized. Primarily, the trade-offs outlined within these sub-nexuses are fuelwood vs. crops, use of land for more forests vs. more cropping, and water availability for agroforestry vs. agroforestry impacts on the water cycle. Despite the positive outcomes and opportunities, agroforestry systems in the Sahel still face some challenges such as vague land use rights, inadequate capacities and lack of investments. Policy recommendations are synthesized at three levels. This synthesis involves remedies to lessen pressures at the interlinks of WELF resource use, overarching remedies in the two sub-nexuses, and remedies across all the sectors and issues for improving agroforestry outcomes. Optimal remedies stress the importance of choosing the right land, water and plant combinations as well as incorporating efficiency measures and alternative sources. A successful agroforestry system is characterized by a conducive environment at the farm level in terms of institutions, management, enhancing the farmer's capacity, and good infrastructure.