Research-for-Development
Highlights
Stories
about progress toward a more competitive and sustainable agriculture
The marketplace at Punata, Cochabamba
Department, Bolivia. |
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In the sections that follow, we present highlights
from the three global research-for-development challenges—Agrobiodiversity,
Agroecosystem Management, and Rural Innovation—that
guide the work of CIAT’s projects. Each of the stories
told here represents a step forward on the road to a more
competitive agriculture that is economically and socially
sustainable.
“Smart” fertilizers and
nitrogen-efficient crops
Researchers at CIAT and the Japan International Research
Center for Agricultural Sciences (JIRCAS) are moving full
steam ahead to exploit a rare biochemical phenomenon from
some tropical pasture grasses—biological nitrification
inhibition (BNI). Triggered by chemical compounds released
from the roots of an African grass widely grown in South America,
this natural process, once harnessed, is expected to make
nitrogen fertilizer use far more efficient.
Nitrification is a process in which soil bacteria convert
ammonium—the nitrogen form in most commercial fertilizers—into
nitrite, and then into nitrate, releasing nitrous oxide, a
powerful greenhouse gas, in the process. Although nitrate
is crucial to the growth of nearly all crops, most of it leaches
down to the subsoil and often pollutes surface and groundwater.
So, finding a way to slow down nitrification to a rate compatible
with good crop growth would both reduce fertilizer requirements
and minimize the deleterious impacts of agriculture on the
environment.
In 1982, CIAT scientist Rosemary Sylvester-Bradley noticed
that soil in which the forage grass Brachiaria humidicola
was growing had more ammonium and less nitrate than would
normally be expected. This observation has led to research
collaboration between CIAT and JIRCAS on BNI.
A joint JIRCAS-CIAT project, launched in January 2002, aims
to get to the bottom of the BNI phenomenon and put it to practical
use. The incentive to combat nitrification is strong. The
direct economic cost of nitrogen losses in cereal production
alone is estimated at US$16.4 billion per year. Moreover,
global agriculture continues to be an important source of
the greenhouse gases implicated in global warming, and nitrate
pollution of water is a growing threat to the environment
and human health.
Recent advances are highly promising. The JIRCAS team has
perfected a test that identifies and measures the BNI trait.
Joint work by JIRCAS and CIAT in 2004 also proved that B.
humidicola root exudates are highly effective at inhibiting
nitrification in soil and that the effect is long-lasting.
JIRCAS researchers G.V. Subbarao and Osamu Ito believe that
unravelling the mechanisms of BNI in B. humidicola
will have important implications for developing “smart”
nitrogen fertilizers that do not undergo rapid nitrification
in soils.
The work to date suggests several promising strategies to
harness BNI, some of which are currently being pursued. During
2004 the CIAT team used the JIRCAS assay to screen 10 samples
of B. humidicola from the Center’s seed bank.
“We found three accessions of B. humidicola that
have significantly greater capacity for BNI than the standard
cultivar Tully, and we’re now testing these in the field,”
says Marco Rondón, a biogeochemist with CIAT’s
Tropical Soil Biology and Fertility (TSBF) Institute.
Apart from conventional breeding to enhance BNI, it should
also be possible, over the longer term, to isolate, sequence,
and clone BNI genes from B. humidicola and introduce
them into economically important field crops through genetic
transformation. Building “fuel efficiency” right
into the very genomes of major crops has enormous potential
to cut both production costs and global agriculture’s
share of greenhouse gas emissions and nitrate pollution of
water.
Integrating folk and formal soil
ecology
For Kenya’s small farmers, soil fertility management
is not just a matter of maintaining a chemical balance in
the topsoil but rather brings into play their knowledge of
soil ecology. With support from Canada’s International
Development Research Centre (IDRC), researchers in CIAT’s
Tropical Soil Biology and Fertility (TSBF) Institute are testing
an interactive learning strategy with four communities in
western Kenya to promote dialog between farmers’ “folk”
ecology and formal scientific knowledge.
This approach contrasts with conventional agronomic research
methods, which often ignore local knowledge systems. While
not a panacea, farmers’ knowledge about factors such
as soil types, nutrient content, composting, and crop response
to organic and inorganic amendments is vital, since it guides
their decisions about farming.
Through dialog, experiment design and implementation, evaluation,
and knowledge sharing between farmers, researchers, and extensionists,
CIAT researchers are creating a more dynamic approach to solve
soil fertility problems.
“Our project results dispel the idea that integrated
soil fertility management is somehow too complicated a topic
for participatory research with farmers,” says CIAT
anthropologist Joshua Ramisch. “Yes, it’s complex,
but farmers deal with complexity all the time—with weather,
pests, diseases, soils, and multiple crops. You can use soil
management as an entry point for participatory research on
natural resource issues.” The challenge now, he says,
is to scale up the use of community-based learning strategies
so that knowledge sharing can take place among larger numbers
of farmers and development partners. This is a key aim of
the second 3-year phase of the project, which has continuing
support from IDRC.
Strong community interest is driving the push to scale up
the process. Since 2001 participating farmer groups have grown
from four to twelve. Today, the groups conduct eight collective
experiments and over 200 individual ones. And they’re
applying soil fertility management concepts, not just to maize
and beans (the region’s main staples), but also to women’s
high-value vegetable crops and to other staples like millet
and cassava.
Documenting the process and its results is crucial. The project
team has produced a manual outlining the use of interactive
learning techniques. The farmer groups have also been busy
documenting their work and creating communications products,
such as local language data sheets giving soil experiment
results, calendars with photos and descriptions of successful
practices, and short dramas, poems, and songs for building
community awareness.
Estimating future health gains
from biofortified crops
In a study of the potential human health benefits of breeding
cassava and beans with higher micronutrient content, CIAT
social scientists have come up with a wide range of possible
benefit levels for the scenarios they modelled. The analysis
behind these “educated guesses,” they say, suggests
that the size of the benefit per population is highly context-specific,
depending especially on postharvest losses of micronutrients
(such as iron and vitamin A), on people’s eating habits,
and on existing levels of micronutrient deficiency.
Under an optimistic scenario for Northeast Brazil, cassava
rich in vitamin A could curtail ill health and deaths due
to deficiency in that vitamin by 19 percent. Under a pessimistic
scenario, the reduction would be only 4 percent. In the case
of iron-rich beans, optimistic and pessimistic scenarios were
modelled for Nicaragua as well as Northeast Brazil. In Brazil
the reduction in health problems would range from 24 to 47
percent and in Nicaragua from 19 to 45 percent.
The yardstick used by the researchers is called disability
adjusted life years, or DALYs. Commonly used to evaluate health
interventions, this system of measurement incorporates both
mortality and morbidity (sickness) into a single index of
human health-related well-being.
Estimates of two key variables were used to set out the optimistic
and pessimistic scenarios. These were the projected postharvest
losses of the micronutrients—for example, through processing
of cassava into flour—and estimates of future varietal
adoption rates among farmers.
Besides that, the scenarios took account of breeders’
views as to the potential increases in micronutrients they
might be able to achieve under the HarvestPlus Challenge Program
of the Consultative Group on International Agricultural Research
(CGIAR). In the case of beans, CIAT breeders expect to be
able to raise iron content by 80 percent. As for cassava,
specially bred varieties will likely end up having around
15 parts per million of beta-carotene, the precursor of vitamin
A, versus a near-complete lack of that compound in the cassava
varieties currently eaten by most people.
CIAT coordinates the crop breeding component of HarvestPlus,
which is a global program. For the breeding work, it has responsibility
for micronutrient biofortification of beans and cassava.
Strategies for seed security during
African emergencies
Like many of the natural and human-made disasters that afflict
Africa over and over, seed aid given in response to crisis
has itself become chronic. So much so that several countries
have seen the rapid and dramatic rise of “relief seed
systems,” offering entrepreneurs opportunities to profit
from the misfortune of others.
These seed systems, explains a 2004 report prepared jointly
by CIAT, Catholic Relief Services (CRS), and CARE Norway,
emerge from a simple sequence of events. “A disaster
is declared, seed need is assumed, and then a well-established
chain of suppliers moves into action.” But the automatic
assumption about farmers’ need for seed, according to
the researchers who conducted eight case studies in seven
African countries, is faulty.
This “knee-jerk reaction,” as CIAT social scientist
and study leader Louise Sperling calls it, is generally the
result of lack of diagnosis and analysis at the outset of
an emergency. The research results show that during events
such as drought, floods, and war, farmers actually get most
of their seed from local channels. The study confirms the
“availability of seed on a large scale” even when
outside aid is being offered, suggesting that local seed systems
are more resilient than governments and relief agencies have
generally thought.
“We now know that sometimes doing nothing is better
than doing something,” says Sperling. “There are
ways of responding that may undermine agricultural systems,
and there are ways to stabilize and strengthen them.”
By adding a learning component to seed aid, she adds, practitioners
increase the probability of long-term benefits from current
and future interventions.
The case studies were conducted jointly with public and private
organizations involved in seed relief work in Burundi, Ethiopia,
Kenya, Malawi, Mozambique, Uganda, and Zimbabwe. Funding was
provided by the Office of Foreign Disaster Assistance of the
US Agency for International Development (USAID) and the Norwegian
Ministry of Foreign Affairs.
A series of 12 “practice briefs—on topics such
as seed system security assessment, agrobiodiversity and relief,
the introduction of new crop varieties, and a checklist for
preparing seed security proposals—has been produced for
seed aid practitioners. These will be available in print and
on the World Wide Web from CIAT and other organizations by
late 2005. A manual for rapidly assessing seed system security
in the field during or before an emergency is also near completion.
Fighting food insecurity through
agroenterprise development in Haiti
Haiti’s chronic vulnerability to political and other
types of upheaval is accompanied by the unfortunate distinction
of being the poorest country of the Americas. The causal links
among grinding poverty, loss of forest cover, the effects
of natural disasters (such as deadly flooding in 2004), the
shoe-horning of 8.5 million people into the western third
of an island that covers only 76,000 square kilometers, an
intense dry season that bakes the soil, and lack of economic
opportunity are hard to untangle. But together they spell
a perennial threat: food insecurity for millions of poor people.
CIAT is working closely with World Vision to tackle this
issue by assisting farmer groups in three target areas with
the establishment of seed production systems and other agroenterprises.
In cooperation with the Ministry of Agriculture, CIAT staff
are also building R&D capacity among government institutions
and community groups.
A continuing concern about food security is the need for
a timely and large enough supply of good-quality seed. “There’s
always a shortage during the planting season,” says
Aart van Schoonhoven, former director of CIAT’s Agronatura
Science Park. “Aid agencies are always worried that
farmers will be forced to eat their seed rather than plant
it.”
In the case of dry beans, a key source of dietary protein,
farmers usually buy seed at local food markets and therefore
have little idea of the nonobvious traits that the resulting
crop will display. Under a 2-year project that began in mid-2004,
CIAT is working with local community groups to set up bean
seed production systems. The first farmer cooperative was
formed in late 2004. Technicians and farmers have been trained
to establish and manage local seed production and commercialization.
CIAT and World Vision are also helping community groups set
up solar cassava-drying enterprises to supply the animal feed
market. Inexpensive and easy to manage, the drying plants
provide a model for development in other communities.
To enhance the effectiveness of these efforts, CIAT is introducing
participatory extension methods, which help fuse local knowledge
with formal science. In the hands of technicians with World
Vision and other NGOs, these methods contribute to wider adoption
of technical innovations.
Combining disease resistance with
consumer tastes in cassava
With funding from the Rockefeller Foundation, CIAT began
an ambitious 6-year effort in 2003 to help Tanzania exploit
recent genetic improvements to cassava, an important food
staple. The idea was to transfer new disease- and pest-resistant
cassava genotypes from CIAT in Colombia to Africa and then
cross them with local cultivars to produce cassava suited
to African conditions. Now, 2 years later, hundreds of plants
are growing in the Tanzanian crossing block. The symptoms
of cassava mosaic disease (CMD), which appeared shortly after
planting and had scientists worried about a possible breakdown
of their germplasm’s CMD resistance, have vanished.
The plants are strong and healthy.
The CMD resistance is particularly important since this disease
is found only in Africa and is highly destructive. Moreover,
an aggressive strain of the plant virus that causes CMD, spread
by whiteflies, has been devastating crops in eastern Africa
for more than a decade. In Uganda in the mid-1990s, it even
triggered deadly famine in some areas.
About 12 years ago, a new source of CMD resistance was discovered
by CIAT’s sister center, the International Institute
of Tropical Agriculture (IITA). Later, CIAT identified molecular
markers for the gene responsible for the resistance. The markers
allow for accelerated breeding, a big plus given the long
growth cycle of cassava. Under the Tanzanian project, national
scientists are being trained in marker-assisted selection
methods.
The experimental cassava also possesses New World genetic
diversity, which African breeders can now exploit for various
purposes—to alter plant architecture for easier weeding,
boost the protein content, or improve nutrition, for example.
Broadening the gene pool will create alternatives for both
African breeders and farmers, such as cassava production for
industrial starch. “We’re giving the farmers not
only new materials but new economic opportunities,”
says CIAT molecular geneticist Martin Fregene.
But breeding cassava for home consumption and to meet consumer
food preferences is also important. “The local varieties
are very good for giving the right quality of flour,”
notes Edward Kanju, an IITA cassava breeder working in a Rockefeller
Foundation-funded project on resistance to cassava brown streak
disease in eastern Africa. “What we will do now is select
genotypes that combine both sets of traits.”
The final test of success, though, will be acceptance of
new varieties by producers. To ensure research relevance,
the project calls for strong farmer participation through
varietal testing and selection of crosses.
Participatory rice research:
An entry point for crop diversification
For many people rice conjures up the image of a big internationally
traded commodity, a cash crop produced on large tracts of
irrigated land using modern mechanized methods. But in Central
America, as in many other parts of the world, this image doesn’t
fit reality. In Nicaragua, for example, about two-thirds of
rice production is cultivated under rainfed conditions, most
often by small farmers using traditional techniques.
CIAT’s rice research project focuses on these small
producers and, to a lesser extent, on medium-scale producers
in Latin America. While upland rice provides them with some
cash and a measure of food security, the international price
is so low that earnings are rarely enough to pull rural families
out of poverty.
In collaboration with France’s Center for International
Cooperation in Agricultural Research for Development (CIRAD),
CIAT has been working since May 2002 with more than 100 farmers
and farmer groups in Nicaragua to improve and select varieties
of upland rice. “Nicaragua is a good laboratory and
testing ground,” says rice breeder Gilles Trouche, who
coordinates CIAT and CIRAD’s participatory rice research
in that country. “It is very representative of Central
America, where upland rice is grown under a range of agroecological
conditions using diverse cultural practices.”
Part of the poverty-alleviation rationale for the participatory
research is that improved rice production—made possible
by varieties that yield better, mature earlier, or tolerate
drought—will give farmers greater flexibility in their
use of land and labor. This in turn will allow them to more
easily diversify into higher value crops, without losing the
food security provided by rice. Participatory research on
rice (as well as sorghum) also provides a practical entry
point for building farmers’ capacity to innovate and
organize, says CIAT’s rice research project manager
Lee Calvert.
Varietal selections were made from a range of available CIAT
and CIRAD germplasm by participating farmer-researchers during
2003 and 2004 in four different rice ecosystems. In 2005,
six promising rice lines entered the validation phase, in
which they will be evaluated in commercial plots by larger
groups of farmers—the final step before new varieties
are officially released by INTA, Nicaragua’s National
Institute of Agricultural Technology.
The project has helped, in a modest but real way, to strengthen
these farmer groups. “In addition to the new skills
they have acquired,” says Trouche, “they are also
better now at interacting with scientists and presenting experiment
results to other farmers.”
Prize-winning collaboration to protect
plantain
Smallholder farmers in Colombia have been working with international
and national scientists and extension agents for the past
3 years to save their stands of plantain from bacterial wilt—“moko”
in Spanish. Among the promising weapons in the emerging arsenal
is a liquid biocide that does double duty as an organic fertilizer.
Called a lixivium, the liquid is produced inexpensively on-farm
by composting plantain residues, specifically the hanging,
spine-like shafts called rachises from which the flowers and
fruit protrude. This is the part of the plant that farmers
routinely discard after harvest.
“We wanted to give the farmers simple, easy-to-use
solutions because they don’t like complex technology,”
says Silverio González, director of Colombia’s
National Federation of Plantain Producers (FEDEPLATANO) and
chief designer of the composting system. “Our members
prefer to solve problems using their own local resources.”
The lixivium biocide is much more environmentally friendly
than the formaldehyde farmers typically use to disinfect soils.
CIAT’s collaborative work with FEDEPLATANO and other
organizations over the past 3 years, via a broad alliance
called Club del Moko, was one of three winners at Innovation
Marketplace 2004. The exhibition-cum-competition is designed
to strengthen partnerships between centers of the Consultative
Group on International Agricultural Research (CGIAR) and civil
society organizations. The winners were announced during the
CGIAR’s annual general meeting at Mexico City in October
2004.
CIAT plant pathologist Elizabeth Alvarez, who has long experience
in farmer participatory research, has worked with FEDEPLATANO
on several aspects of moko control. She has also collaborated
with the Colombian Corporation for Agricultural Research (CORPOICA),
a Club del Moko member, to study the genetic diversity of
the bacterium that causes moko, Ralstonia solanacearum. Using
molecular markers, Alvarez and colleagues identified 68 strains
in samples of plant tissues, soil, water, and insects. However,
detecting the bacteria not only in the laboratory but also
in farmers’ fields is essential to make best use of
control measures like the lixivium. Development of an on-farm
diagnostic kit is therefore a priority in the next research
phase.
Indigenous agroforestry: A bright
spot in land management
A form of agroforestry practiced by 6,000 hillside farm families
in Honduras has proven highly successful at not only protecting
land and water resources but also improving rural livelihoods.
Known as Quesungual agroforestry, this indigenous farming
system was enhanced and promoted under a project launched
by the Food and Agriculture Organization of the United Nations
(FAO) in the early 1990s.
In a recent evaluation of that experience, scientists from
CIAT and FAO conclude that the Quesungual system, or elements
of it, could be successfully adapted for use in highland areas
of Africa, Asia, and South America. Their evaluation was part
of the “Bright Spots” Project, carried out by
a consortium of nine institutions, including CIAT.
Quesungual is the village in western Honduras from which
the agroforestry system takes its name. Under this form of
natural resource management and cropping, native trees share
space with field crops such as beans, maize, sorghum, millet,
and forage grasses, as well as newer high-value crops, mostly
fruits and vegetables. The hillside trees are carefully pruned
to reduce nutrient competition with food and forage crops
and to provide mulch.
The system contrasts strongly with the slash-and-burn shifting
agriculture typically practiced in the highlands of Central
America. Under the Quesungual system, farmers never burn the
hillside vegetation as a way to prepare land. And they use
no-till and direct seeding methods for food crop cultivation.
That way the land is permanently covered, protecting soil
from two extremes to which the region is prone: torrential
rains, which cause severe erosion, and drought, which saps
soil moisture.
The evaluation report notes that farmers were able to double
both bean and maize yields. This allowed them to meet their
own household food needs and still have a surplus to sell.
Their higher incomes have allowed farmers to invest in higher
value crops like vegetables and fruits, and to buy chickens
and pigs. The evaluation study authors also comment that enhanced
access to credit, along with policies on burning, overgrazing,
and water management, were essential to the project’s
success.
Building an arable layer of soil
in the savannas
Brazil, Colombia, Venezuela, and other countries endowed
with vast tropical savannas have great expectations for these
resources. They see them as a last frontier of arable land,
a means of expanding crop production and generating regional
economic wealth within their borders. But, as the research
experience of CIAT and other scientists has demonstrated,
this will be nothing but a pipe dream unless the currently
infertile, degraded soils of the savannas can first be built
up—almost from scratch.
Savanna soils are often acidic, high in aluminum (which is
toxic to plants), and low in organic matter. Without dramatic
improvements in the physical, chemical, and biological characteristics
of these Oxisols and Ultisols, it won’t be possible
to introduce sustainable, no-till crop agriculture.
CIAT has worked on the problems of savanna soils for about
30 years, using an area of Colombia’s Eastern Plains
called the Altillanura as its living laboratory. With Colombian
partner organizations, it has designed a two-phase set of
soil management practices for building an arable layer.
In the first phase, aimed at improving the soil’s physical
and chemical properties, the earth is cultivated with a rigid
set of curved chisels that reach a depth of 30 centimeters.
This tillage system replaces traditional disk harrowing, which
penetrates the native savanna only 5 to 8 centimeters. This
first phase also includes the application of chemical fertilizers
to build up essential nutrients.
Next is the biological phase. Forage grasses and legumes
adapted to tropical savanna conditions are planted. Taking
advantage of the loosened soil and nutrient bonus, these plants
produce abundant root systems that penetrate the full profile
of the topsoil. As the soil improves in fertility and structure,
it becomes more suitable for direct sowing of commercial crops
such as maize, soybean, and rice. In the cropping phase of
this soil-building exercise, farmers are advised to follow
specific crop and pasture rotations in their newly emerging
agropastoral systems, based on improved germplasm.
“We’re making productive an area that has been
unproductive for so many years,” says CIAT soil physicist
Edgar Amézquita. He adds that the arable layer system
is not only technically feasible but also economically attractive
to farmers. In a 2004 study of the potential impact of these
technologies, the three agropastoral options evaluated by
Amézquita and colleagues all scored high for potential
profitability. Expressed as internal rates of return, scores
ranged from 20 to 57 percent.
CIAT’s principal partners in this work are CORPOICA,
the National Program for the Transfer of Agricultural Technology
(PRONATTA), the Colombian Institute for the Development of
Science and Technology (COLCIENCIAS), and the Colombian Ministry
of Agriculture and Rural Development.
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