Agricultural technologies and tropical deforestation - Center for ...

224 David Yanggen and Thomas Reardon
6.1. Kudzu-improved fallow adoption
Kudzu fallow adoption is positively and significantly correlated to farm size,
distance to social infrastructure (schools and health posts) and distance
to markets. Even though kudzu fallows have the effect of increasing the
productivity of land, their adoption does not appear to follow a traditional
Boserupian scenario of intensification induced by land scarcity, increasing
population and proximity to population centres (Boserup, 1965, 1981; Pingali
et al., 1987).
Farms with parcels that have been in production longer and with less
primary forest have a significantly higher probability of adopting kudzu
fallows. Both variables indicate decreasing land quality. The longer a farm has
been in production, the more depleted its soil is of nutrients (fallows take longer
to regenerate). Less remaining primary forest implies greater depletion of
above-ground nutrient stocks contained in the vegetatives biomass.
In the land-abundant environment around Pucallpa, we cannot yet talk of
a closing of the land frontier in quantitative terms. Farmers typically cultivate
only a small proportion of their farms and/or have access to nearby land.
However, given that farmers are subjecting the region’s fragile tropical soils
to slash-and-burn agriculture with declining fallow periods, land quality
increasingly constrains production. Much of the adoption of kudzu-improved
fallows is associated with the closing of the land ‘quaslity’ frontier.
More educated farmers and farmers with sandy soils adopt kudzu fallows
significantly more often, while those with credit adopt them less. Education’s
positive correlation indicates that understanding nitrogen fixation and managing
kudzu in an improved fallow system require a relatively high level of
knowledge. This is particularly true given that kudzu fallows have tended
to spread informally among farmers without much support from extension
services. Higher educational levels may also be associated with greater opportunity
costs for labour. More educated farmers may adopt labour-saving kudzu
fallows to free themselves in order to benefit from increased opportunities to
work off-farm.
The negative correlation with credit makes sense in that kudzu-improved
fallows enhance productivity without using capital and with lower labour
inputs. Thus, they offer an attractive alternative for farmers without access
to credit. The positive correlation with sandy soils probably relates to the
agronomic conditions in which kudzu flourishes.
The overall significance of our model is reasonably good for this type of
cross-sectional adoption analysis (R 2 = 0.39, R 2 = 0.26). This is particularly
true given the multipurpose nature of kudzu in the region. Farmers use kudzu
to improve fallows, as pasture/fodder and as a perennial cover crop. Our survey
was not always able to distinguish between these three uses clearly and
consistently, and this may have reduced the model’s predictsive power.