Fragile Lands of Latin America Strategies for ... - PART - USAID

168 Susanna B. Hecht
than 60% of tropical agronomic research budgets involve surveying,
mapping and classifiing soils, and fertilizer and management trials.
This research, along with climatic data and germplasm selection is
viewed as essential for developing the scientific basis for technical
transfer of improved crops and cropping systems. In the main, these
results argue that soil constraints, often considered to be the most
critical agronomic limitation, can be overcome by the application of
fertilizers and other modem inputs (Sanchez et al. 1982; CPATU, 1984;
CIAT, 1984, 1987). One of the arguments used to justifjl conventional
soil research is the idea that if production systems, especially annual
production systems could be stabilized through the use of modern
inputs, then the migration and deforestation linked to cropping failures
would be diminished.
The Yurimaguas Model
The most famous Amazonian example of modem soil management
research is that developed by Sanchez's group in Yurimaguas, Peru.
Following the U.S. Land Grant College model of agronomic research
and development, soil and crop management strategies focus on target
crops or soil problems, with minimal reference to local knowledge
systems and indigenous land use practices. This kind of approach has
generated useful results but as a strategy it concentrates primarily on
what scientists have been able to learn through the application of
scientific techniques to narrowly defined pedological/agronomic prob-
lems. The overriding response to the soil management problems has
emphasized agronomic techniques rooted in temperate zone agricultural
intensification models that consist principally of fertilizer applications
(Sanchez et al. 1982, Sanchez 1985, Sanchez and Benites 1987). In
approaching soils issues in this manner, a large body of local knowledge
about soil potential and management has been ignored.
There are a number of reasons why a soil management approach
based on chemical fertilizers, such as the Yurimaguas model, is open
to question. Some of these issues have been outlined elsewhere (Fearn-
side, 1987) but include agronomic issues such as: 1) soil nutrient
imbalances, and micronutrient deficiencies that cannot be easily mon-
itored by most Amazonian peasants; 2) pest outbreaks that can reduce
yields regardless of soil management; 3) erosion problems; and 4)
physical changes in soil properties. Institutional issues include: 1) the
availability of inputs at the proper time; 2) access to inputs; and 3)
adequate quality of inputs. Finally there are market factors such as: 1)
adequate return, 2) affordable transport costs; and 3) affordable credit.
Broader structural questions that impinge on the use of such technol-