Water Smart: The role of water and technology in food security
The recent drought-related famine in East Africa has put the focus on the need to make smarter use of existing water resources and, where possible, make more water available for food production. Smart water management technologies will provide the foundation for both approaches. While some will be new, most are likely to be existing technologies adapted to new circumstances.
Water is essential to grow crops but it is not widely appreciated that agriculture consumes large quantities of water. Massive population growth worldwide, along with climate change, are increasing competition for limited water resources.
Despite the gravity of the problems there is every reason for optimism. Modern irrigation is one of the success stories in recent decades. Only 20% of the world’s cultivated land is irrigated, yet it produces over 40% of the world’s food and fibre needs. Large irrigation projects in India, China, Pakistan and Indonesia have fed millions of people who otherwise would have starved. The green revolution, in the 1960s and 1970s, concentrating on rice irrigation, lifted Asia out of an imminent hunger crisis. Potential remains to increase irrigated farming and many least developed countries (LDCs) have large, untapped endowments of rainfall that can be harnessed using conservation farming practices and supplementary irrigation.
But moving beyond simple rainfed farming and harnessing water resources for food production will require significant investment in technologies to store water, measure and control flows for irrigation, lift water, and collect the data on which management decisions are made. Many LDCs lack such infrastructure and investment. The problem has been exacerbated by the lack of aid donor interest in water management technologies over the past 30 years following disappointing investments in irrigation in the 1960s and 1970s. Rather, institutional development has been the priority. Technology is not just a feature of water management, it is essential and successful irrigation requires it to be applied.
Context is everything
Large public irrigation systems depend on technology to distribute water to farmers, but the high costs of large schemes, concerns about their social and environmental sustainability, and the lack of benefits for the poorest farmers have slowed new developments in recent years. In many LDCs attention has shifted away from engineering large irrigation schemes to a focus on smallholders who depend on agriculture for their livelihood. About 80% of people in Africa and Asia are smallholders. They rely on rainfall and/or irrigate small farms and home gardens, often less than one hectare in size.
Technology can greatly reduce the drudgery of lifting water and applying it to crops in an adequate and timely manner. The right technologies must be simple, reliable, easy to maintain, and be sensitive to gender specific needs, not least because two-thirds of people living in water-stressed areas are women. The choice of technology will not just be determined by function. Context plays a crucial role – where it is being used, by whom and how it is introduced. The latter is poorly understood and is one of the main reasons for so many past technology failures.
Substantial improvements are possible in rainfed agriculture, particularly in sub-Saharan Africa and South Asia. Tapping this potential requires innovative strategies to manage the sudden excesses of water and frequent dry spells. The technologies are not new. Integrating soil and water management focused on soil fertility, improved rainfall infiltration, and water harvesting can significantly reduce water losses, and improve yields and water productivity. The strategy is to get ‘more crop per drop’. The greatest potential for improvement lies in those areas where most of the hunger and poverty exists.
Benefits from existing technologies
Most benefit is likely to come from promoting and using existing technologies and adapting them to new circumstances, rather than developing new technologies.
Water storage has the greatest potential to deliver more water for food, capturing water when it is plentiful and making it available when there are shortages. Apart from dams, storage can also mean holding water in natural wetlands and reservoirs, in groundwater aquifers, soils, and in small tanks and ponds. Many smallholders buy pumps and exploit local groundwater rather than relying on the uncertainties of canal water. The challenge is to find ways of reinventing canal irrigation and making it as responsive as groundwater irrigation.
Modern irrigation technologies, such as sprinkler and micro irrigation, have potential for adaptation to smallholdings, particularly where farmers are growing high-value marketable crops and where water is scarce. Affordable systems, such as bucket and drum drip irrigation kits, have been developed for small plots and vegetable gardens predominantly cultivated by women.
of treadle pumps, orig-inally developed in Bangladesh, has revolutionized water
lifting. As has the availability of small, cheap petrol, diesel and electric
pumps, the development of cheap well drilling technology, rural
electrification, and subsidized
energy. These innovations can, however, give rise to over-exploitation.
The potential of information and communications technologies
More creative use of information and communications technologies (ICTs) can facilitate smarter water management. Cell phones offer a means of providing valuable information and advice to farmers in remote places. In Uganda, for example, farmers can call their questions in to a free telephone hotline. Local operators search for answers and provide information on crop prices, weather forecasts for irrigation and water management, plant diseases and more.
Geographic information system technology is another useful tool. More than 6,000 traditional water tanks were identified by this means in a single sub-watershed in the Krishna basin. If restored to capture just 15%-20% of local rainfall they could be used to expand the irrigated area in the region by 50%.
is essential. Asian governments initiated their green revolution in the 1970s
by spending 15% of their annual budgets on
agriculture. The World Bank estimates that a 1% increase in agricultural GDP in Africa would reduce poverty 3 or 4 more times than a 1%
increase in non-agricultural GDP. Yet donor countries spend less than 5% of their development aid on agriculture.
Food crises in
recent years have helped elevate agriculture onto the world agenda, and the
international community is beginning to re-engage in water management for
agriculture. Technology can provide the tools for the job; it is up to the
various stakeholders, smallholders, researchers, policymakers and governments
to find ways to use them wisely so that we can
become more ‘water smart’.
This article is abstracted from the unctad (2011) Water for Food – Innovative water management technologies for food security and poverty alleviation.
WATER FACT FILE
- Agriculture consumes 70% of all water withdrawn from rivers and aquifers globally.
- The average European diet requires about 3,500 litres of water each day – 2-5 litres for drinking, 150 for cooking, cleaning and washing, and the rest for producing food.
- In North Africa, South Asia and sub-Saharan Africa, millions of people must survive on less than 1,000 litres per day.
- More than 1.4 billion people live in water-stressed rivers and basins and by 2025 the number is expected to reach 3.5 billion.
- More than 20% of the world’s rivers run dry before reaching the sea.
- Only 20% of the world’s cultivated land is irrigated, yet it produces over 40% of the world’s food and fibre needs.