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An Information Solution
for Africa's Soil Health Crisis
In a new effort to halt the rapid degradation of soils in
sub-Saharan Africa, the International Center for Tropical
Agriculture (CIAT) has embarked on the development of a digital
soil map - called the African Soil
Information Service (AfSIS) - which will cover all 42 countries
of the region. The map will help reduce one of the main obstacles
to a long-awaited renaissance of food production on Africa's
small farms.
 A spreading obstacle to agricultural growth
About 500 million
hectares of the region's agricultural land are moderately or
severely degraded. And the problem is rapidly getting worse because
of increasing pressure on the land - the result of growing
population and food demand, combined with extremely low use of
inorganic fertilizers and organic sources of plant nutrients.
Applying just 8 kilograms of fertilizer per hectare, on average,
African farmers return only 10 percent of the nutrients that
farmers in the rest of the world apply to the soil.
Soil degradation represents a major obstacle to the reduction of
hunger and poverty in Africa, impeding much-needed increases in
agricultural productivity. Declining soil fertility means
particularly severe limitations for women, given the prevalence of
gender inequality in access to fertile land and to cash for buying
improved seed and fertilizer.
Efforts to improve African soils have been hampered by a lack of
up-to-date, comprehensive information about soil conditions. Such
information is critical for identifying the types and amounts of
mineral and organic nutrient sources needed to boost crop
yields.
"Soil management in sub-Saharan Africa must be improved
dramatically if we are to reduce poverty, feed growing populations
and cope with the impact of climate change on agriculture,"
says Nteranya Sanginga, director of CIAT's Nairobi-based
Tropical Soil
Biology and Fertility (TSFB) Institute.. "Achieving this
requires accurate, up-to-date information on the state of
Africa's soils."
A new collaborative initiative
AfSIS will help overcome the current scarcity of information
through a soil-health surveillance system. Drawing on the latest
technology from soil science, together with the use of remote
satellite imagery and analysis of thousands of soil samples from
across the continent, the system will make it possible to map areas
at risk of soil degradation and provide detailed information on
appropriate interventions for reversing the problem.
The development of AfSIS will be supported through a 4-year
grant of US$18 million from the Bill & Melinda
Gates Foundation and the Alliance for a Green Revolution in
Africa (AGRA). CIAT's TSBF Institute will lead the effort,
which was formally launched at Nairobi in mid-January of this year.
The new digital soil map will be developed as part of a global soil
mapping initiative, called GlobalSoilMap.net.
Partners in the effort include the Earth Institute at
Columbia University in the USA, the World Soil Information
(ISRIC) at Wageningen University in The Netherlands and the
World Agroforestry
Center (ICRAF), headquartered at Nairobi, Kenya. AfSIS will
initiate collaboration with national agricultural research programs
across Africa, including the establishment of regional soil health
laboratories in Tanzania, Mali and Malawi. Experiments will be
conducted in Kenya, Tanzania, Malawi, Nigeria and Mali to develop
recommendations on soil fertility management.
Maps that make a difference
AfSIS will monitor soil health though continuous and systematic
collection, analysis and interpretation of data. These will consist
of "legacy" data (that is, printed soil maps and other
information already available) as well as satellite imagery,
feedback from users, the results of agronomic experiments and soil
sampling done by staff of national institutions at 60
"sentinel" sites. These sites are areas of 100 square
kilometers being selected randomly in 21 African countries.
One especially useful source of data will be that gathered
through infrared spectroscopy, using procedures developed by the
World Agroforestry Center. Based on the interaction of
electromagnetic energy with matter, this technology is proving to
be a quite reliable and cost-effective means of rapidly determining
soil health, based on analysis of the chemical and physical
properties and organic matter content of soil samples.
Such data make possible digital soil mapping. This involves the
creation of geo-referenced information (that is, information linked
to a specific pixel on a satellite image of a particular location)
about soil properties, based on randomized statistical sampling as
well as statistical prediction of soil properties across landscapes
that may not have been sampled. The resulting high-resolution maps,
covering some 18 million square kilometers, will be highly useful
for planning, implementing and evaluating efforts to enhance soil
management and for targeting such efforts to many locations.
Another major step will be to develop the data management
systems required to make ASIS (and eventually the global service)
available via Internet. In this task, the Columbia University
Center for International Earth Science Information Network (CIESIN)
will build on databases already partly developed by the Global
Digital Soil Mapping Consortium.
The new system will be distinguished from current resources by
its more open "cyber-infrastructure," designed according
to the latest advances in information science, Internet technology
and scientific database development. The idea is to foster a
two-way flow of information, so that users, such as AGRA and its
partners, can both receive and provide valuable soil
information.
To be truly useful, though, the digital soil maps must be
accompanied by evidence-based soil management decision frameworks
to guide the formulation of recommendations at the regional,
national and local levels. Without such an approach, efforts to
improve soil health will continue to depend too much on trial and
error.
In addition, AfSIS will include a spatial database containing
the results of soil management experiments carried out across
Africa. On the basis of such data, computer models can be used to
predict the performance of recommended soil management options
under diverse conditions.
A Renaissance within reach
The traditional approach to soil mapping involves static soil
classes, based on a system of soil taxonomy, which is difficult for
nonspecialists to understand. AfSIS may sound rather complicated
too. The important difference is that it will actively reach out in
different ways to diverse groups of users and beneficiaries.
Toward that end, the project will give special attention to the
development of diverse means for sharing soil information,
including Web sites, simple manuals, digital atlases and policy
briefs. In addition, it will undertake a large program of local
capacity building, aimed at researchers and extension specialists,
initially in Tanzania, Malawi, Kenya, Nigeria and Mali. AfSIS will
also work closely with extension agencies, local agro-dealers and
community-based groups to ensure that the service reaches its
intended beneficiaries.
Through AfSIS, the TSFB Institute and its partners hope to make
commonplace and routine an instructive experience it had while
formulating the project proposal. Malawi's Ministry of
Agriculture requested guidance in improving the efficiency of
fertilizer use under its bold and innovative input subsidy program,
which has helped boost the country's production of staple food
crops in recent years. In response, TSBF conducted a workshop in
Malawi last April to help formulate a new set of policies and
recommendations, which are very likely to be adopted.
Once AfSIS is available, it will facilitate many such
consultations, involving not only researchers and policy makers,
but large numbers of farmer associations, extension officers and
private businesses.
Photos
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Severe soil degradation in Western
Kenya. Photo by ICRAF, T. Terhoeven-Urselmans
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Severe soil degradation in Western Kenya.
Photo by ICRAF, T. Terhoeven-Urselmans
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Success: Farmer in Nyanza Province (Kenya)
sees results in crop planted in soil recovered from soil
erosion. Photo by Peter Okoth, TSBF-CIAT
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Success: Well fertilized soils produce
results for Kenyan farmers. Photo by Peter Okoth, TSBF-CIAT
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