multipurpose tree species research for small farms: strategies ... - part

and coconuts, coffee, and various tree fruits the
major perennial crops. About 35% of farmers'
income comes from food crops, 20% each from
livestock and off-farm employment, and the rest
from perennial crops and forest products.
Current Technology
The extension and research components of the
project started simultaneously in 1985. The
extension strategy is to form farmers into groups,
demonstrate improved iechnology on 10ha
demonstration plots (formed from several
individual farmers' plots) in one year, followed by
an expansion to a further 50-300ha surrounding
each demonstration plot the following year. Soi!
conservation has placed great emphasis on terrace
and waterway construction, with subsidies of
fertilizer and seed for food crops. Grasses
(Setaria),legume trees (Leucaenaleucocephala,
Sesbaniagrandiflora)and fruit trees are distributed
for planting on terrace risers,
Farmers' adoption of grasses distributed for
planting on terrace risers has been high, due to
their value as fodder. The potential for livestock as
a source of income is considered to be high, but a
major constra;nt is fodder production, especially in
the dry season. Increasing this fodder supply,
through cut and carry systems of grasses and
MPTS is likely to be very compatible with erosion
control.
Terracing which has been a major part of the
technolog, extended by the project, is less suitable
for the widespread shallow soils in the area. If
done well, it is expensive. Because of these
problems, there is growing interest in reducing
erosion through vegetative means, rather than by
terrace construction. Alley cropping as a possible
alternative has received much attention recently,
but there is insufficient knowledge of practical
technology standards for widespread
implementation, and the likely impact of these on
productivity and conservation,
Research Priorities
The issues faced with alley cropping in the
context of the project was to decide what is known,
and what needs to be known. The state of
knowledge concerning the suitability of alley
cropping for the UACP areas can be broadly
summarized.
The principles of alley cropping as a means of
soil fertility maintenance have been demonstrated
as valid on other continents, notably Africa. The
principles of alley cropping as a means of erosion
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control through the barrier effect, mulching by
cuttings, and changes to soil properties are
taken as accepted (Young 1988). However, the
magnitude of these effects on production and
the economic benefits in the project area,
compared to alternative technologies, are
unknown.
Farmers in other areas of SE Asia and
Indonesia have adopted alley cropping as a
means of soil conservation and forage
production. The practice of alley cropping is
said to have originated in Timor (Metzner in
Raintree and Warner 1986).
Farmers in UACP areas plant several MPTS,
includingL. leucocephala,Gliricidiasepitmn, and
S. grandiflora. These species are usually grown
as scattered trees in homegardens or as
hedgerows along plot boundaries. However,
there are a few cases whereFlemingeacongesta
and other species have been planted intensively
as regularly spaced hedgerows in upland plots.
Many of these represent prior introductions by
government programs, such as the regreening
program, during recent decades. Farmers'
knowledge concerning the fodder and soil
conservation potential of these MPTS is unclear.
Much of the cultivated uplands in the project
area is already terraced to some degree,
although the standards of this terracing for
runoff anid erosion control are generally poor.
Terraces are usually 2-5m wide, and cassava is
often grown along the terrace edge where the
soil is the deepest and the cassava easy to dig.
This means that it is difficult to implement
hedgerows precisely alon the contour, alley
widths are largely determited by terrace width,
and benefits of MPTS on terace edges will have
to be visible enough to displace the cassava.
Uncultivated upland areas, covered by
hnperatacylindricaor other grasses, are
common in the project area. The long-term use
or rotation of this type of land, and its
importance for grazing and fodder collection
has not been well studied. Consequently, the
potential for MPTS as a fallow improver, fodder
source or means of introducing permanent
cultivation is largely unknown.
L. leucocephalahas been severely affected by
the psyllid in recent years, In some initial
obsei ration studies by the project, F.congesta
has shown vigorous growth. The extension
component of the project has started to include
F.congesta in demonstration plots on shallow
limestone soils.