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.
The introduction
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%.
Funding
Adequate funding
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.