Preininger D., Lojka B., Bechynì M., Hlavsa T.
Abstract
Widespread land use method to obtain farmland in tropics is traditional slash-and-burn farming. The cultivation is
feasible only in condition of long fallow period, otherwise this leads to weed infestation and soil degradation.
The objective of this stud implemented in the Peruvian Amazon around the city of Pucallpa was to determine possible
use of Inga edulis for control of some weed species (e.g. Imperata brasiliensis) and how different agricultural
practices influence weed occurrence. The study evaluate four treatments: (1) natural fallow; (2) cropping system
with cassava; (3) planted fallow with Inga edulis; (4) planted fallow with I. edulis and kudzu (Pueraria phaseoloides).
Weed biomass were measured at 3, 6, 9, 13 ,17, 20, 24, 28 and 32 months after fallow initiation. Weed samples were
enumerated by counting the number of weeds by species in each subplot. On the research plot, about 20 most frequent
weed species were determined. Highest frequency had Imperata brasiliensis; 185.1 individuals m-2 at three months
and 31.4 individuals m-2 at 32 months (Inga + Pueraria). Aboveground biomass reached 180.9 g.m-2 at three months
for Inga fallow. Results have shown that all four treatments led to successful control of grass weed species.
But because of the poor development of Inga trees on severally degraded soil, the trees could not suppress the weeds
by shading. The trees would probably need more time to prove this ability.
Key words:
Imperata brasiliensis, improved fallow, Inga edulis, weed control, slash-and-burn