Tm. Nissen et al., Biophysical and economic tradeoffs of intercropping timber with food cropsin the Philippine uplands, AGR SYST, 67(1), 2001, pp. 49-69
Steadily rising prices for timber on Mindanao in the Philippines have given
an incentive to farmers to devote some of their land to fast-growing tree
species. The costs and benefits of intercropping young timber trees with fo
od crops was studied in a 1000 stem ha(-1) stand of Paraserianthes falcatar
ia. At 2 years of age, diameter at breast height and height of intercropped
trees were 33 and 21% greater, respectively, than sole trees. Management c
osts of intercropped trees were less than half of sole trees. Allometric eq
uations for Mindanao falcataria were used to project future tree growth and
system returns. In the base scenario (1000 trees ha(-1), 5-year rotation),
the sum of biophysical and economic benefits of intercropping trees with a
maize/vegetable rotation for two years were less than the costs of reduced
intercrop yield, compared to sole cropping of each component. A linear rel
ationship of crop decline to the increase in basal area of the stand was us
ed to predict returns to intercropping under alternative tree densities and
intercropping periods. Intercropping becomes more attractive as labor beco
mes scarcer relative to land, the need to minimize cash inputs becomes more
important to farmers, and trees increase in value relative to annual crops
. (C) 2001 Elsevier Science Ltd. All rights reserved.