Resource information
The most traditional and widely used
farming systems in the humid upland tropics are based on
fallowing and various forms of slash-and-burn agriculture.
Their sustainability depends on the duration of the fallow;
as long as the fallow stage is longer than seven or eight
years, slash-and-burn systems usually remain efficient. They
produce a moderate yield using a low-input technology that
is especially efficient in terms of returns to labor. With a
few exceptions, yield per hectare and labor returns decline
when fallow duration drops below the threshold of seven or
eight years. This decline can be interpreted as the loss of
the "forest rent," one of the main concepts used
in this study. Forest rent also applies to most perennials,
which despite their name are often managed under a kind of
shifting cultivation. As coffee, cocoa, and even rubber
farms are sometimes abandoned to "fallow" and
replanted later on, a tree crop system may well be
considered as an extended form of shifting cultivation,
hence the concept of tree crop shifting cultivation used in
this study. If the coffee or cocoa farms are not abandoned
for several years to enable a regrowth of a secondary
forest, replanting is more difficult or more costly than
initial planting. Yields and revenues can be expected to be
lower. This decline of revenues and increase of costs
matches the concept of the loss of forest rent.
