Agriculture Reference
In-Depth Information
One example of how CA principles can be applied to dryland areas is found in
southern Africa. Here, the traditional system is to plow the land using manual or
animal power just after the onset of the rainy season. In part because of seasonal
labor shortages, land preparation is often delayed, crops are planted late, plant stands
are poor, fertilizer is not used, and weeding is performed either late or not at all
(Waddington, 1999). In an improved CA system, farmers make planting basins
(depressed areas in the field) during the dry season. When the rains begin, water
accumulates in the basins. Farmers can immediately seed into the preprepared wet
basins. Farmers are also encouraged to “microdose” fertilizers (use very precise
application of very small amounts) and compost.
Timely planting, improved soil moisture in the basin, and better nutrient avail-
ability can lead to substantially higher yields while actually reducing peak season
labor requirements. Rotating crops in the basins every year helps control pests and
diseases. Weeds may still be a problem but can be partly controlled by mulching the
land with crop residues. Farmers are encouraged not to burn crop residues but to use
them for composting or as a surface residue cover. When open grazing of residues by
cattle is allowed, however, residue retention may be difficult to impossible.
In animal-powered systems, the farmers use a ripper plow to open a furrow,
where water is harvested. Burning is discouraged, and residues are left in the furrow.
Planting is done by hand or behind the plow, with microdosing and concentration of
nutrients near the seed. Both of these systems resulted in earlier planting, less labor,
higher yields, and improved soil health over time (Bwalya, 1999). Interestingly, use
of herbicide-resistant crops could make this system even more productive since
weeds are still a major problem.
Introduction of improved two-wheel and small four-wheel tractors could also help
accelerate the adoption of this more sustainable technology in the future. However,
there are still many opponents to introduction of mechanized power into African
farming. The one thing that is not contested is that present traditional systems have
resulted in major soil degradation, nutrient loss, and declining yields, and that this
must be reversed in the future.
extensIon of technology
New agricultural production technology is of little use unless large numbers of farm-
ers adopt it and use it over large areas. Many models have been used in the past to
address this issue. In traditional, linear extension systems, scientists develop technol-
ogy, hand it over to extension agents, who in turn pass it on to farmers. This assumes
that scientists fully understand farm systems and constraints faced by farmers. As
this is not always the case, technology adoption using traditional extension systems
is often disappointing.
To overcome low rates of adoption of agricultural technologies, the World Bank
introduced in the 1980s a “training-and-visit” (T&V) system, intended to upgrade
the technical capacity of extension workers and facilitate closer contact with farmer
communities (Hussain et al., 1994). Farming systems research (FSR) was also intro-
duced in the 1980s to make research more relevant to farmer's circumstances, but
both still relied too much on a linear system of researcher-dominated research. In
