|Theme 2 : Productive Water Use
This theme addresses primarily how water is used, and can be used more productively, in irrigated, rainfed and wetland agro-ecosystems thus contributing to sustainable intensification and increased food production. It focuses on challenges arising from both physical and economic water scarcity, by creating sustainable options for adaptive management of water that increase water productivity and the benefits gained from water for livelihood purposes. The potential contribution of rainfed and irrigation systems in supporting livelihoods and food production is far from being met across Asia and Africa.
Wetlands offer an important source of water and land resources for agricultural production in sub-Saharan Africa, but intensive use threatens the provision of other ecosystem services. With the continuing challenge of reducing poverty, with food and energy prices on the rise, rapid urbanization and competing demands on water, and with climate change leading to more variability and uncertainty, this theme will provide analysis and tools developed through interdisciplinary research to facilitate:
- Revitalizing irrigation
- Managing water in rainfed systems
- Sustainable use of wetland
2.1 Revitalizing irrigation
The performance of irrigation is stagnating and declining in a number of systems across Asia, and irrigation performance has been disappointingly low in sub-Saharan Africa. The Comprehensive Assessment of Water Management in Agriculture suggests that investment in irrigation will reduce poverty in rural areas, help meet demand for agricultural products and adapt to changing dietary and societal demands, adapt to urbanization, industrialization and increasing environmental allocations and respond to climate change. Root causes of underperformance of existing irrigation systems are poor maintenance and poor policies and institutions that shape the environment in which irrigation operates and lack of uptake of new technologies that improve the physical behavior of the systems. The theme will give special emphasis to salinity as it threatens long-term productivity of many irrigation systems. IWMI will focus not only on improving physical/technological and governance performance of large irrigation schemes, but also on new small schemes and supplementary irrigation opportunities that will particularly enhance the livelihoods of the poor and women. In collaboration with theme 4, we will explore ways in which community based institutions can help to achieve improved irrigation performance.
- To increase the productivity of irrigation water at system to field scales
and thus benefit food production and livelihoods
- To formulate adaptive management strategies and institutional and policy reform to improve irrigation system performance to facilitate productivity improvements
2.2 Managing water in rainfed systems
Rainfed farming systems in sub-Saharan Africa and parts of South Asia suffer chronically from low productivity, resulting in entrenched food insecurity and poverty for rural populations. Rainfed systems depend upon green water and in many respects are much harder to manage than irrigation systems. Water productivity tends to be very low and evaporation losses are high, due to land degradation, crop losses, and inadequate or nonexistent water management. In semi-arid areas prolonged dry spells and drought are often the cause of crop loss, a situation that will be exacerbated by climate change. Managing water in rainfed system holds a key to improved productivity and livelihood support. This includes better management of rainfall, and also soil moisture and use of irrigation water to supplement rain. It will also require improved understanding of land water interactions.
IWMI will work with partners who specialize in crops and livestock to develop a range of options to upgrade rainfed systems with better water management. The Comprehensive Assessment of Water Management in Agriculture considered that better water management of rainfed systems will cut yield losses in dry spells, give farmers security to risk investing in other inputs such as fertilizers and high yielding varieties and to grow higher value market crops, which are currently susceptible to water stress and require costlier inputs.
- To upgrade rainfed farming systems and benefit smallholders through improved land and water management interventions and technologies
- To support improved water management in rainfed farming systems and thus rapid outscaling of innovations via identification and promotion of appropriate policies and institutional reforms
2.3 Sustainable use of wetlands
Use of wetland ecosystems for agriculture presents an important livelihood opportunity for millions of rural poor, but at the same time there is an imminent threat that ecosystem services provided by wetlands - domestic water supply, food control, fisheries, livestock, biodiversity, ecotourism, and provision of raw materials - will diminish. In physically scarce river basins wetlands tend to dry up as water is taken away to serve agriculture and city users. Wetlands are of vital importance for community coping strategies during times of drought and which may have increasing importance as a consequence of climate change and increased climate variability. Often it is the poorest whose livelihoods are most dependent on wetlands. Yet, in spite of the upsurge in use of wetland waters, wetland use in agriculture and its impact on other ecosystem services are poorly understood.
- To protect ecosystem services, livelihoods and water productivity in wetlands through better knowledge of how agricultural activities impact wetland functions
- To reduce poverty through improved agriculture, fisheries, and livestock management in wetlands via identification of effective management strategies and policies to protect vital ecosystem services