Title: TropSoils
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00080625/00001
 Material Information
Title: TropSoils the first three years and beyond : summary
Series Title: TropSoils
Physical Description: 7 p. : ; 28 cm.
Language: English
Creator: Soil Management Collaborative Research Support Program
Publisher: TropSoils, North Carolina State University
Place of Publication: Raleigh N.C
Publication Date: 198-?
Subject: Agriculture -- Research -- Tropics   ( lcsh )
Soil management -- Tropics   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Funding: Primary funding is provided by the U.S. Agency for International Development.
General Note: Cover title.
 Record Information
Bibliographic ID: UF00080625
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 154312070

Full Text

the first three years
and beyond

the problem
To meet the demand for food in
developing nations, yields on existing
farmlands must increase and an addi-
tional 200 million hectares of newly
cleared land must be brought into pro-
duction during the next 20 years. Since
the greatest need, and the greatest
potential for agricultural growth, are
both in the tropics, most of the new
lands will be found there. While
tropical climates are, with some excep-
tions, favorable to crops, unfavorable
chemical properties or inadequate
moisture in many tropical soils severely
constrain plant growth. Without proper
soil management, many infertile fields
are abandoned, crusted soils become
barren, steeplands erode, and valuable
rain forests are cut unnecessarily. The
problem is one of how to increase
yields and sustain food production over
the long term, while conserving for
future generations an important
resource base-the soils.

TropSoils is a collaborative research
program whose goal is to develop and
adapt improved soil-management
technology that is agronomically,
ecologically and economically sound
for developing nations in the tropics.
Primary funding is provided by the U.S.
Agency for International Development,
in support of Title XII, "Famine
Prevention and Freedom from Hunger"
of the Foreign Assistance Act.

global plan
To accomplish its goal, TropSoils
employs a global plan first articulated
by its Planning Entity, and endorsed by
USAID. The plan's strategy is to bring
the expertise of U.S. land grant univer-
sities to bear on soil-related constraints
to food production in developing na-
tions in the tropics. On the basis of
their experience in tropical research,
collaborating universities were chosen
to lead programs in several key sectors
of the tropical environment. These sec-
tors are called agro-ecological zones.
While no zone is a homogeneous unit,
the soil constraints are similar enough
to provide a focus for the research pro-
gram. Within the zones, the universities
develop primary research sites in order
to maximize resources and establish the
necessary continuity.

agro-ecological zones
The agro-ecological zones are:
the humid tropics, where the dry
season is no more than three months,
the native vegetation is rain forest, and
soil acidity and infertility are common
constraints to crop production;
the semi-arid tropics, where a dry
season of six to nine months wind and
water erosion, desertification and
nutrient deficiencies create serious
the acid savannas, characterized by
a dry season of four to six months,
savanna vegetation, and soils that are
commonly acid and low in nutrients,
but physically favorable to cultivation,
the steeplands, where the terrain
makes erosion a serious environmental
and agronomic concern.

TropSoils' approach to work in these
zones is based on several fundamental
assumptions: The research should
employ established principles of soil
and crop science, and adapt them to
conditions in the agro-ecological zone.
In some cases, basic research should be
conducted to fill gaps in current
knowledge. The soil-management
technology packages generated through
research should be transferrable to
other sites, and should also be flexible
enough to accommodate both the user
and the resource.

Another important aspect of this ap-
proach is collaboration. Collaboration
ensures that partner nations have a
stake in TropSoils research, that it
meets their needs, and that the pro-
gram draws on the broadest possible
base of knowledge and expertise. Col-
laboration also helps partner nations
develop a pool of skilled leaders and
scientists, and links these people and
institutions into a network equipped to
solve soil-management problems.

TropSoils was formally initiated in
September, 1981. The next step was to
develop the necessary agreements with
governments and institutions, then to
equip and field teams of researchers
and technicians. Although the program
is young, there are already substantial

sum mary I

continuous cultivation

Research in the Guesselbodi forest of
Niger found that simply mulching barren,
crusted soils with the branches left over
from wood-cutting greatly increased soil
moisture and porosity, and promoted the
natural re-seeding of key forest species.
This research could play an important role
in the fight to preserve valuable forests
and slow desertification in Africa's Sahel.

Adapting a West Texas farm implement
to animal power, scientists showed that the
"sandfighter" holds great promise for pro-
tecting young millet crops from sandstorms
in Africa's Sahel. Plans are underway to
test the device, which forms tight clods
that trap sand and reduce the blast and
burial of young plants, on Niger's exten-
sion farms. The research could eventually
help Sahelian farmers decrease crop loss
and increase food production.

Building on years of successful research
in the Cerrado region of Brazil, researchers
have begun a comprehensive set of studies
aimed at finding practical, inexpensive
ways to manage nitrogen and increase
yields on acid-savanna soils. In one promis-
ing study, mucuna, a common green
manure, has proven that it can survive a
dry season to supply succeeding food crops
with a large portion of the nitrogen they
require. This kind of low-cost approach to
nitrogen management could increase the
productivity of farmers in the acid savan-
nas and elsewhere, who very often cannot
afford chemical nitrogen.

Researchers at Yurimaguas, Peru, dis-
pelled some long held misconceptions
about tropical soils when they established
that, with careful management, adequate
fertilization and lime, continuous cultiva-
tion of food crops is possible on the acid,
infertile soils of the Amazon Basin. After
21 consecutive crops, a rotation of rice,
corn and soybeans yielded an average of
7.8 tons of grain per hectare per year, and
overall soil fertility in the test field actually
improved. The findings may help save
many hectares of rain forest by reducing
the need for clearing new fields.

After demonstrating that continuous
cultivation of food crops is possible in the
acid, infertile soils of the humid tropics,
scientists at Yurimaguas have taken the
next step to put together a low-cost, "low-
input" technology that will enable poor
farmers to multiply yields without relying
heavily on expensive chemicals and equip-
ment. This low-input technology, which in-
cludes the use of hearty, acid-tolerant
cultivars, conservation tillage, residue cy-
cling and small amounts of fertilizers, has
produced rice yields five times greater
than those on the typical farmer's field.
The technology offers an important transi-
tion stage between traditional no-input,
shifting cultivation and high-input crop-
ping in the humid tropics.



Paddy-rice research at Yurimaguas has
inspired a booming new industry in the
Peruvian Amazon. Peruvian workers at the
research station used the paddy-rice
techniques they learned there to establish
their own rice plantations. They suc-
ceeded, and more settlers followed,
establishing a community of some 30
families, each with 20 or 30 hectares of
flooded rice. Last year, Peru was self-
sufficient in rice for the first time in many
years, largely because of the expansion of
flooded-rice agriculture into the Amazon.

land reclamation
Research on Amazon Basin farmland
abandoned after being damaged by
bulldozers has shown that practical deep-
tillage treatments can restore porosity and
productivity to compacted soils, multiply-
ing yields of corn and soybeans. This
research raises the hope that some aban-
doned lands can be reclaimed, and sup-
plies guidelines for soil management on
future sites that must be cleared

Testing ways to improve grazing lands in
the Amazon, where pastures are often poor
due to infertile, acid soils and badly
adapted forage species, scientists at
Yurimaguas have found combinations of
grasses and legumes that provide a stable
pasture and increase the rate of animals'
weight gain by up to eight times the rate
on a typical farm in the Amazon. Such
studies could help reduce the rate of land-
clearing in the Amazon's valuable rain
forests by increasing the per-hectare yield.

A new system of classifying soils by their
fertility and cropping potential has greatly
simplified the job of evaluating new
farmland in the tropics. The system, called
Fertility Capability Classification, has been
refined and tested with TropSoils support,
and is being rapidly adapted for use by
research and extension centers around the

Using innovative approaches that have
raised considerable interest in the U.S. and
abroad, an anthropologist specializing in
farming systems has helped soil scientists
work with farmers to improve research
and farming techniques in the Sitiung
transmigration settlements of Indonesia.
Through interviews, time-allocation studies
and on-farm observation, the research
team has been able to assess the settlers'
skills and needs, and has used the informa-
tion to begin shaping the kind of soil-
management practices best suited to the
people and setting.

Drawing on the varied expertise of soil
scientists from two U.S. universities, the
research team in Indonesia has found a
way to deal with the extreme variability of
crop responses over small areas-a prob-
lem common on acid, tropical soils, and
one that plagues farmers and scientists
alike. Their solution saved not only time,
but also has contributed to a vital study of
crops' fertility requirements.

paddy rice


subjects in common
TropSoils' research plan calls for each
university to continue to study and solve,
through collaboration, the primary soil
constraints to crop production in its respec-
tive agro-ecological zone. Because many of
these soil constraints are found in more
than one zone, the various programs are
connected by subjects of common interest
and importance, and research in one zone
often complements research in another.
The following statements briefly describe
some of these subjects, and the new Trop-
Soils work that addresses them.

Soil acidity constrains crop production
by limiting root growth, and by reducing
the absorption of water and nutrients. New
research will draw on established prin-
ciples of acidity management, applying
them to site-specific conditions of soil and
climate. Liming studies will examine types
of lime, methods of incorporation, and fre-
quencies and rates of application. A wide
range of cultivars is being evaluated for
their productivity and tolerance to soil

In their natural state, most tropical soils
do not supply enough of the plant
nutrients essential for good crop produc-
tion. Previous research has shown that
high crop yields can be sustained if these
fertility limitations are corrected. New
studies will focus on the rates and times of
fertilizer applications, sources of fertilizers,
the role of micronutrients, and the major
elements, primarily phosphorus and

Nitrogen is frequently the nutrient most
limiting for plant growth and also one of
the most difficult to manage. The goal of
TropSoils' nitrogen-management compo-
nent is to develop effective ways to
manage nitrogen from both plants and fer-
tilizers, so as to sustain crop production.
New studies are designed to improve the
use of biologically fixed nitrogen, incor-
porating legume green manures and crop
residues into practical cropping systems.

One of TropSoils' most formidable
challenges is to develop management
technologies that can minimize soil-water
constraints to plant growth across the
range of conditions found in the tropics.
The approach is to capture and retain rain-
water by improving the physical condition
of the soil surface with tillage, plant cover
and catchments. State-of-the-art
mathematical expressions are being used to
estimate the quantity of water that will be
available to plants, and the quantities lost
through run-off, evaporation and transpira-
tion. Studies will also focus on water in the
root zone, seeking ways to make soil
moisture more available to crops by im-
proving the management of tillage, crop-
ping systems, lime and fertilizer.

It is unlikely that many tropical farmers
will adopt, in the near future, technologies
based on the intensive use of fertilizers,
lime and farm machinery. Therefore, a
transition crop-production technology is
needed. Using low-input techniques
developed during previous TropSoils
studies, the new research will examine an
array of low-input farming options, in-
cluding the use of adapted cultivars and
low levels of fertilizers and herbicides.

Many of the new lands that must be
brought into production will first be
cleared of vegetation. The quality of the
clearing operations affects how productive
the land will be, and, therefore, the success
of the farm family. In collaboration with
IBSTRAM, an organization that is also con-
cerned with soil-management research,
TropSoils will conduct a comprehensive
study of the existing knowledge on land-
clearing technology. This information base
will then be used to develop (1) a strategy
for land-clearing research and (2) a net-
work of land-clearing projects to provide
important new information. A TropSoils
land-clearing project will be the first link
in this network.

land reclamation
From the semi-arid regions to the rain-
soaked humid tropics, the work of nature
and man have combined to degrade
farmlands and impair crop production. A
number of TropSoils projects will focus on
reclaiming barren, eroded or otherwise
degraded land through the use of plant
residues, cropping systems and tillage.

The landscapes and climates of the
tropics are such that land can frequently
be best used by combining crops with
trees. TropSoils is investigating agroforestry
systems that will provide opportunities for
both low- and medium-input production
systems. These studies will examine the
use of trees in wood and fruit production,
in alley cropping, and in improved fallows.

To sustain a highly productive and stable
agriculture, it is necessary to formulate
farming systems that conserve soil. Trop-
Soils will use established principles that
relate erosion to rainfall and wind
characteristics, and will adapt and refine
these principles as necessary to develop
farming practices that will conserve soil in
each agro-ecological zone.

soil characterization
A knowledge of the properties and
distribution of soils serves as a cornerstone
in the development and extrapolation of
soil-management practices. A research pro-
gram on the characterization, classification
and interpretation of soils will provide a
better understanding of the edaphic basis
upon which soil-management recommen-
dations are developed. This knowledge will
enable the researchers to better evaluate
successes and failures in the transfer of
continued next page


To meet its objectives, TropSoils must
develop technology that can be transferred
beyond the primary research site, improv-
ing food production in developing nations.
To predict the performance of a crop on a
specific kind of soil, it is necessary to
match the requirements of the crop to the
characteristics of the soil. A hypothesis be-
ing tested by TropSoils is that the success
of extrapolating soil-management tech-
niques can be predicted through systems
analysis, and by simulating the soil, plant
and atmosphere continuum. TropSoils is
part of a major collaborative effort that in-
cludes several organizations also working
on this hypothesis.


Before soil-management practices can be
adopted they must first be tailored to the
needs and resources of the farmers, and to
their culture. A user-oriented program,
TropSoils projects are studying such factors
as seasonal patterns of work, nutrition,
diet, income and the division of labor by
age and sex. Research teams are including
this information, and also farmers' sugges-
tions, in the design of some research proj-
ects. These activities help ensure that
research results will be useful to the peo-
ple they are intended to serve.

about TFopSoils
TropSoils is a collaborative research program whose goal is to develop improved soil
management technology for developing countries in the tropics.
Primary funding is provided by the U.S. Agency for International Development through
Grant DAN 1311-G-SS-1083-00. This action is in support of Title XII "Famine Prevention
and Freedom from Hunger" of the Foreign Assistance Act.
The formal collactorators in the program are:
Agency for International Development-USA
Center for Soils Research-Indonesia
Cornell University-USA
Empresa Brasileira de Pesquisa Agropecuaria-Brazil
Institute National de Recherches Agronomiques du Niger-Niger
Institute d'Economie Rural-Mali
Institute Nactional de Investigacion y Promocion Agraria-Peru
International Crops Research Institute for the Semi-arid Tropics-India
North Carolina State University-USA
Texas A&M University-USA
University of Hawaii-USA

Copies of this document and two companion reports, TropSoils, the first three years, and
the TropSoils Triennial Technical Report, are available from TropSoils, Box 7113 Williams
Hall, North Carolina State University, Raleigh, N.C. 27695-7113.

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs