Washington, DC
December 4, 2006In
reporting new forecasts of the devastating impact of climate
change on food production in some of the globe’s poorest
regions, the world’s largest alliance of international
agricultural research centers today announced it is embarking on
a new effort to intensify and streamline research to reduce
developing countries’ vulnerability to climate change caused by
global warming.
The Consultative Group on International Agricultural Research
(CGIAR), in consultation with the global environmental change
science community, is refining a comprehensive climate change
agenda that is already generating climate-resilient innovations,
including crops bred to withstand heat, salt, submergence or
waterlogging, and drought, and more efficient farming techniques
to help poor farmers better use increasingly scarce water and
fragile soil. Researchers are also focusing on boosting
agriculture’s role in reducing climate-altering greenhouse
gases. (See attached descriptions of new crops and approaches.)
"The impacts of climate change
on agriculture will add significantly to the development
challenges of reducing poverty and ensuring sufficient food
production for a growing population," said Dr. Robert S.
Zeigler, Director General of the
International Rice Research Institute (IRRI), a
CGIAR-supported research center. "The livelihoods of billions of
people in developing countries, particularly those in the
tropics, will be severely challenged as crop yields decline due
to shorter growing seasons."
"Anticipating and planning for
climate change is imperative if farmers in poor countries are to
avert forecast declines in yields of the world’s most important
food crops," said Dr. Louis V. Verchot, a climate change
scientist with the World Agroforestry Centre (ICRAF), a
CGIAR-supported research center. "Yet, adaptation is not a
substitute for reducing new and removing existing greenhouse
gases from the atmosphere—our only long-term option."
Adding urgency to the
researchers’ action plan is a new study that forecasts a 51
percent decrease by 2050 in the amount of India’s most favorable
wheat-growing land. According to a study from one of the
research centers, Can Wheat Beat the Heat", sustained periods of
hotter, drier weather will dramatically shrink India’s
breadbasket and diminish yields, placing at least 200 million
people at greater risk of hunger.
As a result of rising
temperatures, the climatic conditions best suited to wheat
growing will shift away from the tropics—where most of the
world’s poorest countries are situated—toward the poles and to
higher elevations. According to the study, North American wheat
growers will be able to farm new lands as far as 65 degrees
north, 10 degrees beyond their current planting limit. In North
America, wheat growing would extend from its current limit –
extending from Ketchikan, Alaska in the West to Cape Harrison,
Labrador in the East – to less than two degrees beneath the
Arctic Circle. In Eurasia, much of Siberia would become
farmland. While poor tropical countries’ capacity for food
production will diminish, developed countries—most of which are
located far from the equator—will, in many cases, experience an
increase in productive capacity as land that was previously
frost-bound opens to cultivation.
"Developing countries, which
are already home to most of the world’s poor and malnourished
people and have contributed relatively little to the causes of
global warming, are going to bear the brunt of climate change
and suffer most from its negative consequences," said Dr.
Verchot of the World Agroforestry Centre.
Meanwhile, a second study finds
that projected increases in temperature and changes in rainfall
patterns will decrease growing periods by more than 20 percent
in many parts of sub-Saharan Africa. According to the findings
in CGIAR’s research report Mapping Climate Vulnerability and
Poverty in Africa, Africans living in the continent’s poorest
countries are at greatest risk from environments that will
become even less hospitable to agriculture. Most vulnerable of
all are farming families in East and Central Africa, including
Rwanda, Burundi, Eritrea, and Ethiopia as well as Chad and
Niger.
The authors’ findings were
based on analysis that examined such factors as land
degradation, renewable water supply, infant mortality, crop
suitability, disease prevalence, governance, and public health.
"Poor countries are
overwhelmingly dependent on natural resources, and, given their
limited financial or institutional ability to adapt to profound
change, they are severely at risk," said Dr. Zeigler, speaking
on behalf of the 15 research centers supported by the CGIAR.
"Helping poor farmers adapt to climate change will require a
concerted international effort to improve crops, techniques of
cultivation, and soil and water management."
"The task ahead may well prove
bigger and more complex than what we faced at the outset of the
Green Revolution," Dr. Zeigler added. "To feed a growing
population, food production must be doubled over the next 25
years, but now poor countries must do so in harsh environments
that climate change has rendered far less suitable to
agriculture."
Main approaches in the new
climate change agenda outlined by the research centers include
the following:
Developing climate-ready
crops
Researchers are developing more
reliable varieties of food crops capable of withstanding
increased temperatures, drought, and flooding. Heat-resistant
cereals currently under development will provide greater yield
reliability, especially in the tropics and subtropics, where
many crops are grown at or near their thermal optimum, and where
a 1 degree Celsius increase in temperatures during the growing
season can result in a decline in yields of up to 10 percent.
Under these conditions, photosynthesis slows or even ceases
altogether, pollination is prevented, and dehydration sets in.
With increased rainfall and
flooding forecast in many parts of Asia, new breeds of rice
benefiting from a trait that allows the plant to survive
prolonged periods of submergence are already helping farmers on
millions of hectares in India and Bangladesh. Researchers are
also looking to boost rice yields from a shrinking land base by
reconfiguring the plant’s photosynthetic engine so that it more
efficiently converts solar power and atmospheric carbon into
grain.
For drought-prone regions like
Southern Africa, researchers using an innovative molecular
approach to breeding have made progress in developing maize that
withstands prolonged dry periods and infertile soils. This and
other drought-related work, including research that allows crops
to be "programmed" so they mature at the time of year when
conditions are most likely to be favorable for grain
development, regardless of when they are planted, is beginning
to have an impact in farmers’ fields.
Plant breeders will continue to
develop new varieties that can better tolerate the impacts of
climate change, but there are limits to the ability of new
varieties to counteract the effects of heat, drought, and
submergence.
"Adaptation does not guarantee
that farming will be able to continue in an area, or if it does,
that farmer income will remain unchanged," said Dr. Zeigler.
"Some adaptation will involve shifting production from one
location to another."
More efficient use of
resources
Improving farmers’ ability to
use water more efficiently and to better manage their fragile
soil is essential if they are to adapt to the shocks of climate
change. In many farming systems, as much as 70 percent of the
rain falling on a crop is lost to evaporation and runoff and
cannot be used by the plants. Several CGIAR-supported centers
are refining and introducing new and better methods for
rainwater harvesting and storage, shifting to less thirsty crops
and perfecting drip irrigation to deliver precise amounts of
water when and where it is most needed. Conservation farming
techniques refined by CGIAR researchers, such as low- or
zero-tilling in which farmers refrain from plowing their fields,
help to increase the water-holding capacity of soils and
infiltration so more water is available for the crop, moderate
soil temperatures, and have the added benefit of preventing
carbon from escaping from the soil into the atmosphere.
Managing greenhouse gases
The CGIAR-supported centers are
working with farmers to develop and test innovative practices
capable of contributing to the net reduction of atmospheric
carbon on three fronts: stanching the loss of carbon from
agricultural systems; returning carbon from the atmosphere to
plants and soils; and better managing forests and soils. Trees,
which absorb—or sequester—carbon as they grow, thereby reducing
atmospheric carbon dioxide, and the developing-country farmers
who plant them, are at the center of one of the most important
research efforts. CGIAR scientists are working to increase poor
farmers’ participation in carbon sequestration projects by
introducing satellite technologies that verify the carbon they
are removing from the atmosphere, thus allowing them to receive
proper compensation. According to estimates from the
Intergovernmental Panel on Climate Change, agroforestry has the
potential to trap an additional 170 megatons of carbon each
year.
Agricultural systems also
release greenhouse gases—accounting for an estimated 20 percent
of man-made emissions—by clearing trees for fields and pastures,
transforming soil into cultivated land, and burning crop
residues. To reduce the incidence of devastating slash-and-burn
agriculture in the humid tropics, scientists from a number of
the international centers are working with farmers to develop
alternative livelihoods from the very forests they once cleared.
In Mexico, CGIAR scientists have introduced infrared sensors to
farmers to help them reduce the application of nitrogen
fertilizer, which, when applied to crops, produces emissions of
nitrous oxide—a greenhouse gas with 310 times the warming power
of carbon dioxide. Another group of CGIAR researchers in
Colombia has isolated a naturally occurring chemical in African
grass that inhibits the production of nitrous oxide.
Better forecasts, policy
options
To help farmers make better
planting decisions, a consortium of CGIAR-supported centers is
working with national and international meteorological services
and leading climate-modeling researchers to provide local and
regional information that combines forecasting knowledge with
expertise in farming systems. In the local, national, and
international policy arenas, CGIAR researchers are generating
innovative options to foster adaptation to climate change. In
addition, new research at CGIAR-supported centers focuses on
understanding the impacts of climate on natural resources, such
as water, fisheries, and forests, and on planning for improved
management of these resources to meet the needs of growing
populations as the climate changes.
The CGIAR is a strategic
agricultural research alliance dedicated to generating and
applying the best available knowledge to stimulate agricultural
growth, raise farmers’ incomes, and protect the environment. It
supports 15 research centers worldwide conducting groundbreaking
work to nourish the future. For more information, please visit
www.cgiar.org.
DESCRIPTIONS OF NEW CROPS AND APPROACHES
CGIAR climate
change research: breeding climate-resilient crops, managing
greenhouse gases, improving resource-use efficiency
Breeding climate-resilient
crops
Reducing plants' thirst at the molecular level
Drought reduces annual
worldwide maize yields by as much as 15 percent, representing
losses of in excess of 20 million tons of grain. The
International Maize and Wheat Improvement Center (CIMMYT) is
using conventional breeding to develop maize for small farmers
in Southern Africa that withstands drought and infertile soils
and produces yields 30 to 50 percent greater than traditional
varieties. CIMMYT scientists are working to achieve even greater
gains by using tools from molecular biology. With the aid of a
genomic map that combines data for different types of tropical
maize in diverse environments, they are identifying genetic "hot
spots" in maize, that is, areas of the crop's chromosomes that
confer drought tolerance. This work is critical in light of a
recent study that says climate change could inflict a 10 percent
reduction in maize yields in Africa and Latin America during the
coming decades.
Contact: Jean-Marcel Ribault &
Jonathan Crouch,
International Maize and Wheat Improvement Center (CIMMYT)
Tel.: +52 595 952 1900 (GMT-6 hours)
Breeding climate-resilient
crops
New technology helps scientists identify "stay-green" genes to
help sorghum cheat the heat
Crops such as sorghum and
millet—staple cereal grains and fodder crop grown by subsistence
farmers in the hottest, driest regions of sub-Saharan Africa and
the Indian subcontinent—are the most heat- and drought-hardy
crops addressed by CGIAR breeders. Their treasure chest of
stress tolerance genes may someday be unlocked to benefit other
crops, through the marvel of "comparative genomics" research
underway within the CGIAR's Generation Challenge Programme. For
this dream to be realized, the valuable genes have to be mapped
and their functions understood. Researchers at the International
Crops Research Institute for the Semi-Arid Tropics (ICRISAT) are
using a technique known as marker-assisted selection (MAS) to
identify and isolate genes in sorghum that display the
"stay-green" characteristics that allow the plant to mature
normally in low-moisture, high-heat areas. MAS accelerates
classical breeding by locating desired genetic traits on the
chromosomes, setting the stage for plant breeders to transfer
those genes into popular but drought-susceptible varieties or,
eventually, into other cereal crops. "Stay-green" genes delay
the premature death of leaves and plants, help the normal grain
filling, and reduce the incidence of plants "lodging," or
falling over on the ground.
Contact: Mark Winslow,
International Crops Research
Institute for the Semi-Arid Tropics (ICRISAT)
Tel.: +49 (8133) 917-9997 (GMT +1 hour)
Breeding climate-resilient
crops
Boosting rice's photosynthesis
As climate change continues to
shrink the area suitable for rice production, and population
growth continues apace, researchers at the International Rice
Research Institute (IRRI) have turned their attention to a
radical new way to increase yields that involves completely
refiguring what's known as the engine of rice production:
photosynthesis. Armed with new knowledge from the rice genome,
the researchers' aim is to enable the plant to capture solar
energy more efficiently so that it can, in turn, produce greater
yields. Photosynthetically, rice and other so-called C3 plants
like wheat, are underachievers because as much as 40 percent of
the atmospheric carbon dioxide they work to convert to sugar is
lost by respiration in daylight—releasing carbon dioxide into
the atmosphere—a wasteful process called "photorespiration." To
create a more efficient and thus higher yielding rice plant,
researchers would convert the grain to a C4 plant (where "C"
stands for the number of carbon molecules captured by
photosynthesis for growth) that has evolved biochemical "carbon
dioxide pumps" to concentrate atmospheric carbon dioxide in the
leaf, thus overcoming photorespiration. These plants are up to
50 percent more efficient in converting solar energy into
biomass and are fast growing, efficient users of water and soil
nutrients.
Contact: John Sheehy,
International Rice Research
Institute (IRRI)
Tel.: +63 (2) 580-5600 (GMT+8 hours)
Breeding climate-resilient
crops
Fine-tuning a plant's internal clock
Sorghum and millet breeders at
the International Crops Research Institute for the Semi-Arid
Tropics (ICRISAT) are focusing new attention on
photoperiod-sensitive breeding stocks that give farmers an added
tool to adapt to rainfall variability. Plants, like humans and
other organisms, have internal clocks that tell them when to
flower by taking cues from the length of daylight. During the
Green Revolution, breeders of many grains eliminated photoperiod
sensitivity so that plants could be grown anywhere, anytime. The
catch was that these non-photoperiod-sensitive plants required
ideal growing conditions—sufficient water and the right
temperature. In many sorghum-growing regions, the onset of the
rainy season—always unpredictable—may become even more so as the
climate changes. So breeders have had to "program" the crop to
mature at the time of year when conditions are most likely to be
favorable for grain development, regardless of when they are
planted. Photoperiod-sensitive sorghum and millet will catch up
or slow down so their flowering and grain filling occurs at a
roughly constant calendar date, which tends to be the period
when the rains are winding down but there is still enough water
in the soil to complete grain development.
Contact: Mark Winslow,
International Crops Research
Institute for the Semi-Arid Tropics (ICRISAT)
Tel.: +49 (8133) 917-9997 (GMT +1 hour)
Breeding climate-resilient
crops
"Waterproof" rice to protect farmers from devastating floods,
The risk of flooding in
southern Asia's low-lying, rice-growing regions will continue to
increase as climate change leads to greater precipitation in
this and many other regions. In Southeast Asia alone, annual
flood-related losses surpass USD$1 billion, placing millions of
lives at risk of hunger. Rice supplies the majority of calories
for more than 3 billion people worldwide and is the only cereal
crop that can withstand any submergence. Yet even rice will die
if fully submerged for too long. Taking advantage of the
recently sequenced rice gene, researchers at the International
Rice Research Institute (IRRI) and the University of California
at Davis have identified a gene, called Sub1A, found in a
little-used variety of rice, which allows the plant to survive
completely submerged for up to two weeks. When the plant is
covered with water, its oxygen and carbon dioxide supplies are
reduced, which interferes with photosynthesis and respiration—in
which the plant converts sugars into energy for growth. Lacking
air and sunlight, growth is inhibited, and most plants die after
three days. The Sub1A gene, when overexpressed, or
hyperactivated, essentially waterproofs the plant. The
flood-tolerant trait has already been transferred into a variety
of rice, called Swarna, widely grown in Bangladesh, which has
benefited farmers by withstanding floods without sacrificing its
high yield, acceptable taste, or adaptation to regional growing
conditions.
Contact: David Mackill,
International Rice Research
Institute (IRRI)
Tel.: +63 (2) 580-5600 (GMT+8 hours)
Managing greenhouse gases
Satellite imagery helps poor farmers participate in carbon
markets
Researchers at the World
Agroforestry Centre (ICRAF) are using satellite data and
advanced measurement techniques to help developing-country
farmers participate in and receive fair payment for
carbon-removal programs. Poor farmers are among the world's
largest producers of sequestered carbon, yet they are unable to
calculate or verify how much they are removing from the
atmosphere and, thus, are ill-equipped to participate in carbon
sequestration programs. The carbon stored in trees is derived
from carbon dioxide, one of the greenhouse gases responsible for
global climate change. Scientists believe that removing carbon
dioxide from the atmosphere and storing it in trees is one of
the best ways to reduce global warming. It's also one of a
limited number of options available to industries that need to
offset carbon dioxide emissions under the Kyoto Climate Change
Protocol or that have decided voluntarily to reduce their
emissions. The new measurement technology, developed by
researchers from Michigan State University and ICRAF, can
remotely calculate and verify the carbon being stored across
millions of square kilometers of agricultural land and forests
thousands of kilometers away. The new technique, which is highly
accurate, greatly reduces the need for expensive on-the-ground
verification. With fair payment, ICRAF believes that millions of
dollars in carbon credits could begin flowing to the world's
rural poor by 2007, providing an infusion of cash into rural
economies and facilitating sustainable development in many of
the world's poorest countries.
Contact: Louis Verchot,
World
Agroforestry Centre
Tel.: +254 20 722 4000 (GMT+3 hours)
Managing greenhouse gases
Alternatives to slash and burn: Income from tree products
Every year approximately
130,000 square kilometers of humid tropical forest are
destroyed, accounting for up to 25 percent of net annual carbon
dioxide emissions. The devastation is caused in part by poor
farmers who often have no other option for feeding their
families than slashing and burning a patch of forest, growing
crops until the soil is exhausted, and then moving on. The
Alternative to Slash and Burn (ASB) Program, a CGIAR system-wide
initiative, is working with farmers to provide them with
livelihood options that would reduce the incidence of forest
burning. The program has identified "best-bet" alternatives for
slash-and-burn farmers, including integration of trees into
farming—agroforestry. Researchers are working with farmers to
reduce the pressure on forests by providing them with a nearby,
convenient source of food, fuel wood, and timber for
construction and fences. By improving products from the vast and
largely untapped genetic wealth of trees found in tropical
forests, researchers are also demonstrating to farmers the
income-generating potential of tree products such as fruits,
nuts, oils, resins, medicines, cosmetics, fibers, fodder, and
dyes.
Contact: Louis Verchot,
World
Agroforestry Centre (ICRAF)
Tel.: +254 20 722 4000 (GMT+3 hours)
Managing greenhouse gases
Ray guns and African grasses help farmers reduce harmful nitrous
oxide emissions
Nitrogen is one of the keys to
healthy plant growth, which is the very reason that farmers the
world over apply nitrogen fertilizer to their crops. Yet these
fertilizers also increase a process called denitrification in
which microbes convert nitrogen in the soil into nitrate and
nitrous oxide—a greenhouse gas with 310 times the warming power
of carbon dioxide. Researchers at the International Maize and
Wheat Improvement Center (CIMMYT) and the International Center
for Tropical Agriculture (CIAT) are using two different
approaches to reduce nitrogen emissions. A new hand-held
infrared sensor is being calibrated at CIMMYT to help
developing-country wheat and maize farmers maintain their yields
using far less fertilizer. Held above the young, growing wheat
plants, the sensor measures how much light is reflected in two
different wavelengths—red and invisible infrared—which then
helps the farmers determine precisely how much fertilizer should
be applied. Scientists from CIAT and the Japan International
Center for Agricultural Sciences (JIRCAS) are working to exploit
a chemical released from the roots of an African grass grown
widely in South American pastures that naturally triggers
biological nitrification inhibition (BNI). BNI slows the
conversion of ammonium—the form of nitrogen in most
fertilizers—first into nitrite and then into nitrate and nitrous
oxide. Nitrate is crucial to crop growth, but much of it leeches
away, and nitrous oxide has a dual negative effect on the
environment—it is a powerful greenhouse gas, and it contributes
to depletion of the stratospheric ozone layer, making humans
more vulnerable to UV radiation. Slowing nitrification to a rate
compatible with good crop growth would reduce fertilizer needs
and lessen agriculture's impact on the environment.
Contact: Iván Ortiz-Monasterio,
International Maize and Wheat
Improvement Center (CIMMYT)
Tel.: +52 595 952 1900 (GMT-6 hours)
Improving resource-use
efficiency
Providing local water management authorities with a low-cost eye
in the sky
Planners and policy makers in
poor countries often lack the data to manage their regional
water resources effectively. The International Water Management
Institute (IWMI) has created low-cost satellite imaging
techniques that interpret publicly available satellite images to
give an accurate picture of water and land resources at global
and local levels. IWMI recently released a global irrigated-area
map (see
http://www.iwmigiam.org) that provides data and products on
irrigation at various resolutions of sub-national to national
levels. These remote sensing tools complement traditional
methods for tracking water availability and measuring the
productivity of water used in agriculture. Because they often
use high–quality, public-domain satellite images that are
available free of charge from reliable sources such as United
States Geological Survey and the (U.S.) National Aeronautics and
Space Administration (NASA), this approach offers developing
countries a low-cost way to improve water management. The
satellite images help local water management authorities
determine (e.g.,
http://www.iwmidsp.org) where there is available water in a
river basin at various times of the year; where water is
reaching—or not reaching—crops in an irrigation system; spatial
distribution of irrigated areas and their cropping intensities;
areas affected by droughts and their intensities; and the
interaction between the water and the plant in natural
vegetation and agricultural areas.
Contact: Prasad Thenkabail,
International Water
Management Institute
Tel.: +94 112 787404 (GMT +5 hours)
p.thenkabail@cgiar.org
Improving resource-use
efficiency
Drip irrigation: Increasing crop yields while saving water
In Africa and South Asia, the
International Water Management Institute (IWMI) is working with
local partners to scale up simple "bucket and drip" irrigation
system for poor farmers. For as little as USD$5, this technology
allows farmers to apply limited amounts of water to their crops
in a way that saves water and increases yields. In drip
irrigation, water flows from a raised bucket through a filter
into special drip pipes with emitters located at different
locations throughout the plot. Water is discharged through the
emitters directly into the soil near the plants through a
special slow-release technology. IWMI's efforts focus on
countries such as South Africa where large numbers of small
farmers are already feeling the bite of climate change-induced
water scarcity.
Contact: Tushaar Shah,
International Water
Management Institute
Tel: +91 2692 229311 (GMT +5 hours)
t.shah@cgiar.org
Improving resource-use
efficiency
Microdoses of fertilizer allow plants to use precious water
Much of the limited
precipitation that occurs in low-rainfall regions is,
paradoxically, wasted from a farming point of view. This
precious resource flows right by the crop and the farmer because
it often comes in flood surges, it cannot be absorbed by the
degraded soils, or the crops themselves are malnourished and
thus unable to draw water efficiently from the soil. Researchers
at the International Crops Research Institute for the Semi-Arid
Tropics (ICRISAT) are remedying the situation by rectifying the
soil's severe phosphorus and nitrogen deficiency with minute
applications of fertilizer—about a soda-pop bottle capful per
plant, just one-sixth of the amounts used in developed
countries. This practice, called "microdosing," causes the roots
to shoot out early and capture water and nutrients that
otherwise would have gone to waste. Even with African fertilizer
costs approximately three times higher than in those in the
developed world, microdosing is profitable and has resulted in
yield increases averaging around 50 percent in thousands of
trials with millet, sorghum, and maize in West and Southern
Africa.
Contact: Mark Winslow,
International Crops Research
Institute for the Semi-Arid Tropics (ICRISAT)
Tel.: +49 (8133) 917-9997 (GMT +1 hour)
Improving resource-use
efficiency
Doing more with less: No-till agriculture mitigates greenhouse
gases
Using data on soil nutrients
and carbon emissions—and equipped with tractors—researchers at
the Rice-Wheat Consortium (RWC), convened by the International
Maize and Wheat Improvement Center (CIMMYT), are helping farmers
in India and elsewhere radically transform agriculture while
mitigating the release of gases that cause global warming. Much
of soil's carbon content is released into the atmosphere when it
is plowed, or tilled, which farmers do with tractors up to 12
times per planting season. Tilling not only contributes to
atmospheric carbon buildup, but it also increases the need for
fertilizer as the soil is depleted of the carbon needed to
maintain nutrients essential to healthy crop production. In
India's Indo-Ganges region, an increasing number of farmers now
plant wheat seeds directly into the stubble remaining from the
just-harvested rice on a single tractor pass or on the
drastically reduced till fields—not the 12 they are accustomed
to. On each hectare of land, farmers save 50-60 liters of diesel
and approximately 1 million liters of irrigation water. Using a
conversion factor of 2.6 kilograms of carbon dioxide per liter
of diesel burned, this represents about a quarter-ton fewer
emissions per hectare of carbon dioxide, the principal
contributor to global warming. A study has revealed that zero
till (ZT) agriculture-induced water savings (in 3 million
hectares, the current acreage of ZT wheat in South Asia) may be
close to 1.18 billion m3 of irrigation water. In financial
terms, ZT practice on 3 million hectares has resulted in a net
income increase of USD$23 million per season, comprising a
"cost-saving effect" of USD$146 million and "yield effect" of
USD$92 million. Annual diesel fuel savings would amount to a
half-billion liters—equivalent to a reduction of nearly 1.3
million tons in carbon dioxide.
Contact: Raj Gupta,
International Maize and Wheat
Improvement Center (CIMMYT)
Tel.: +52 55 5804 2004 (GMT-6 hours)
Improving resource-use
efficiency
Water harvesting: Learning from desert dwellers
In dryland regions, meager
seasonal rainfall is diffused over such a wide area that it is
of little benefit to plants before it runs off or soaks into the
soil. For hundreds, even thousands of years, farmers in West
Asia and North Africa, some of the driest regions on earth, have
diverted rainfall from large areas into smaller parcels where
the precious moisture can benefit crops or trees. While the
technique, known as water harvesting, is neither high-tech or
new, researchers at the International Center for Agricultural
Research in Dry Areas (ICARDA) are working to compile details on
scores of traditional systems to help farmers refine them and
introduce them to new communities. For example, on the dry
steppes of Jordan and elsewhere in the region, gentle hillsides
resemble large checkerboards covered with a series of
diamond-shaped plots, called negarim, which are bordered by low
earthen ridges. Sprouting from the downhill tip of the diamond,
where the slope's run-off collects, are trees—almond, olive,
apricot, and pistachio. Researchers have helped make negarim
even more efficient by working with farmers to line the pits
with polymer sheets to minimize evaporation from soil surface,
and to use polymers to increase the storage capacity of the soil
so sufficient run-off is kept for the harshest days of the long,
dry summer. In North Africa, farmers build terraced stone and
earth walls, called tabias, across the beds of steep wadis—dry
gullies that flood during rain—to collect and retain soil and
water that otherwise would be washed down the wadis. The tabias
retain enough moisture in the captured soil to grow olives and
barley, the traditional crops, and sometimes apples, apricots,
and chickpeas. In Syria, degraded rangelands benefited from
water harvesting by mechanizing the construction of the
traditional microcatchment ridges using a specialized plow.
Shrubs' survival rate was increased, and the plants survived
prolonged drought.
Contact: Richard Thomas,
International Center for
Agricultural Research in Dry Areas (ICARDA)
Tel.:+ 963-21-2213433 (GMT+2 hours) |