Tropical Kudzu, Maize and Peach Palms Revive Peruvian Soils
A major problem facing farmers on tropical forest soils is the
spread of weeds which become increasingly unmanageable as the
fertility of the soil declines. In the past, farmers simply
abandoned such land to leave it fallow and cut into forest
growth to find fertile land. North Carolina State University and
Peruvian researchers studying ultisol and oxisol soils have
found that one season's growth of nitrogen-fixing tropical kudzu
(Pueraria phaseoloides) can restore the fertility levels
equivalent to 10 years of traditional fallow systems. At the
same time, kudzu actively competes to shut out weeds that
would ordinarily overrun small fields. The research is
particularly interesting because it is being conducted at a
station in Yurimanguas, in the Peruvian Amazon where purchased
inputs are difficult to obtain. Research at the site is oriented
around the needs of local farmers, who market their crops via
river transportation networks.
Kudzu incorporated after eight months followed by maize gives
an excellent maize harvest without the weed problems
associated with leaving the ground fallow. Tropical kudzu,
unlike its temperate relative, is easy to eradicate, because it
does not produce storage roots. It can either be burned off the
soil surface before planting the cash crop, or slashed back and
incorporated into the soil. Other researchers at the center are
intercropping kudzu in a system with rice, cowpeas and
indigenous peach palms. Peach palm seedlings are first planted
in rows with rotations of rice and cowpeas to ensure cash flow
over the first year until the peach palms shade them out. Then
kudzu is planted underneath the palms, which are harvested for
'heart of palm' before they begin fruit production a few years
later.
Agrichemical Age, July 1988, pages 6-10.
See also Science, Vol. 238, 11 Dec. 1987, pages 1521-1527.