Water Resources and Rural Development最新文献

Water management strategies and allocation policies that support agricultural intensification across agro-ecological zones and hydrologic basins are required for building resilient agrarian communities in sub-Saharan Africa. We provide an overview of the research and investments needed to enhance agriculture in the region, with a focus on technology and institutions, while describing opportunities for improving rainfed crop production. We discuss a range of water management practices in three river basins that were part of the Challenge Program on Water and Food research on Basin Development Challenges from 2009 to 2013. Our main message is that technical and institutional innovations in water management are required for creating and sustaining resilient agrarian communities in sub-Saharan Africa. Such innovations are best designed and implemented in consultations involving researchers, households, investors, and other participants with a management or regulatory responsibility. It is in this collaborative spirit that we introduce this Special Issue of Water Resources and Rural Development, in which several authors present results of studies on agricultural water management in the region, with recommendations for better planning and implementation of interventions to benefit smallholder farmers.

Small-scale irrigation is playing an important role in adapting to climate change, achieving food security, and improving household incomes. The Ethiopian Government considers irrigated agriculture as a primary engine of economic growth and plans to increase the current level of irrigation infrastructure three-fold by the end of 2015. However, there has been concern regarding the performance and management of existing small-scale irrigation. Based on the assessment of 52 small-scale irrigation schemes, and three case study sites, we describe the challenges and interventions required to improve irrigation water management in Ethiopia. Though most schemes are operational, many do not operate at full capacity, due to design failures, excessive siltation, poor agronomic and water management practices, and weak local institutions. In addition to low returns, there is competition for irrigation water between upstream and downstream users, vegetable growers and cereal growers, and between farmers with large irrigable plots and those with small plots. Despite these challenges, our field assessment revealed that small scale irrigation increases crop yields, improves crop diversification, and reduces the risk of crop failure. We emphasize in this paper the need for incentives to improve productivity and minimize conflicts, while enhancing innovation capacity, developing scheme-specific intensification strategies, and promoting collective action. We also describe how benefits from water investments could be substantially increased by overcoming design constraints, strengthening water user associations, and protecting catchments.

A major direct use of water from West African small reservoirs is irrigation. Analyzing the performances of irrigated agriculture is therefore a useful way to measure the impact of small reservoirs on food security and livelihoods of local communities. The aim of this study was to assess the performance of two such irrigated schemes in the Upper Volta basin (one in Burkina Faso and the other in Ghana) through participatory methods, to jointly identify major constraints, and to discuss possible solutions with local communities. The agronomic and economic performance of irrigated agriculture at both sites were far from satisfactory, due to the lack of maintenance of the small reservoirs and irrigation schemes, sub-optimal crop management, and poor product marketing. These issues were analyzed with the farmers across differing sub-schemes and cropping systems and some solutions were envisaged. Our assessment showed that farmers often had difficulty obtaining quality agricultural inputs and marketing their products. The poor performance of irrigated crops, due to poor condition of hydraulic infrastructures, poor agronomic management, and organizational failure provided only limited incomes for local households. Nevertheless, the existence and the many uses of small reservoirs improved food security and created indirect activities that also enhanced livelihoods. The local authorities generally considered preserving water to be a priority in small reservoir management, but the degradation of irrigation schemes could happen quickly and result in scheme failures, thus reducing indirect economic activities and causing under utilization or even abandonment of the small reservoir, unless appropriate measures are taken.

With mixed crop-livestock systems projected to be the principal source of food in developing countries in the coming decades, opportunities exist for smallholders to participate and benefit from emerging crop and livestock markets in the Volta Basin. Given the economic, social and environmental vulnerability due to high water scarcity and variability in the basin, improvements in agricultural water management (AWM) are needed to ensure sustainable benefits. A survey was conducted among 326 crop-livestock households in four water scarce sites of the basin in Burkina Faso and Ghana to characterize households in terms of access to water, services and information, AWM intensity and livelihoods, and to explore the linkages between these characteristics.

The sources of water were more diverse for study sites in Ghana than in Burkina, allowing different types of AWM strategies. Most of the farmers perceived a strong positive impact of AWM strategies on their livelihoods. Almost 70% of the variation in livelihood assets was explained by variation in AWM intensity, affecting mainly food consumption, sources of income and housing index. With increasing access to water, services and information, AWM intensity significantly increased, as well as labour for water-related activities and food consumption. This increase in AWM was significantly related to an increase in livelihood assets (R² = 52%). Policies should be developed to improve access to information and services as well as access to market in rural areas of the Volta Basin, to enhance positive impact of AWM strategies on livelihoods of the rural households.

Long-term investments in agricultural water management (AWM) interventions in the Volta and Limpopo river basins have aimed at improving water availability and quality for smallholder farming systems. However, sustained and wider uptake of AWM technologies and approaches has not been as successful. We need to learn from successful AWM interventions, those interventions that have led to a sustained or increased uptake of AWM technologies or approaches, and which have led to improved well-being of farmers and livestock keepers in the rural development context of sub-Sahara Africa. This paper explores AWM interventions, specifically, the impacts these interventions have had and the factors contributing to the success of these interventions.

In four countries within the Volta and Limpopo river basins, consultations were carried in 33 case studies of successful AWM interventions with implementing organisations and beneficiaries using a participatory GIS methodology. A systematic text analysis of 55 case study reports showed that these 33 interventions have had a positive impact on the well-being of beneficiaries and there was a sustained and wider uptake of the AWM technologies or approaches introduced. A clear demand for the technology, appropriate design of the technology, input support, training and capacity building, and a sense of ownership of the community helped to sustain the uptake of AWM technologies and approaches. We conclude that implementing organisations would benefit from investing in the soft components of an AWM intervention, as this will increase the likelihood of successful adoption and adaptation of the AWM technologies and approaches in the long-term.

From field to basin scales, there are many appropriate interventions used to manage rainfall efficiently and productively in smallholder farming systems. Yet, successful targeting and scaling-out of these approaches remains a challenge. This paper presents an innovative approach in decision support called ‘Targeting Agricultural Water Management Interventions’ (TAGMI) with application in Limpopo and Volta river basins (available at http://www.seimapping.org/tagmi/). The online open-access TAGMI uses country-scale Bayesian network models to assess the likelihood of success for outscaling various agricultural water management (AWM) interventions at sub-national level. The web tool integrates multiple sources of expertise on the enabling environment for outscaling based on key social, human, physical, financial, and natural factors. It estimates the relative probability of success of an AWM intervention across the Limpopo and Volta river basins. Here we present TAGMI as a ‘proof of concept’, areas of high, medium, and low probabilities of success for three AWM technologies common in Limpopo and Volta River Basins: the soil water conservation/in situ rainwater harvesting technologies in rain-fed systems, small-scale private irrigation and small reservoirs used for communal irrigation purposes. We then apply a climate change scenario and discuss the robustness in potential AWM, according to the TAGMI tool. Finally, we discuss the need for generic or specific information on ‘best practices of implementation’ for successful uptake of technologies in poverty-constrained smallholder farming systems.

Poverty and food insecurity are common amongst rural communities in the sub-Saharan African region. The rural population of South Africa is not excluded from poverty. With normal conventional tillage practices, crop failures are common on marginal soils in semi-arid areas with low and erratic rainfall. Therefore, selected rural communities in the Eastern Cape, Limpopo and Free State Provinces of South Africa were introduced to appropriate rainwater harvesting and conservation agricultural techniques to contribute towards the reduction of food insecurity through improved maize yields. Conventional tillage, no-till, minimum tillage, mechanized basins, in-field rainwater harvesting and the Daling plough were tested in on-station and on-farm field experiments over three to five maize growing seasons (2008/09–2011/13). The rainwater harvesting (in-field rainwater harvesting and Daling plough) and conservation (mechanized basins, no-till and minimum tillage) techniques resulted in slightly higher yields than conventional tillage due to their potential to conserve rainwater better and to harvest additional rainwater. Conventional tillage, no-till and minimum tillage had lower grain yields because they lost on average 18% of the total rainfall to ex-field runoff. The rainwater productivity of the Daling plough treatment was very similar to that of in-field rainwater harvesting, followed by mechanized basins, conventional tillage and no-till or minimum tillage.

This paper presents empirical evidence of whether participation in community water resource management improves household agricultural income using a case study of irrigation co-management under the Bwanje Valley Irrigation Scheme in Malawi. An endogenous switching regression was applied on a dataset of 412 farmers to correct the outcome (net agricultural income) for sample selection bias. Propensity score matching was then used to measure the impact of participation in irrigation co-management on net annual agricultural income. Despite variations in the magnitude of benefits among different groups, empirical evidence suggests that net annual agricultural income of the poor, youths and female-headed farmers participating in the scheme would have worsened had they not participated in the scheme.