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

agicultural crops. Many of these gardens
illustrate how hill land can be productively and
imaginatively used by farmers though tree
combinations (Thanh and Binh in Littooy 1989).
Livistonasaribas,a palm, is grown in stands to
poduce leaves for thatching. Little is currently
Knon about the relationship between the
cooperatives and farmers in managing these tree
resources.
More recently, farmers have been involved in
state sponsored social forestry tree planting
programs (Folkesson and Gayfer 1989) with the
stated objective of regreening the bare hills and
providing a source of-fuelwood for the rural
population. To date the major species planted has
been Eucalyptus cahialdlensis,reflecting both the
p ojects limited experience with other species and
the cooperative's (and farmer's) preference for a
single stemmed tree with an established local
market for sale as pulpwood to the paper mill. The
actual impact of these plantations on the local
fuelwood problem is likely to be marginal if the
wood can be sold for other purposes or to distant
fuelwood markets at a higher price. Recently,
however, Acacia mnangium and Eucalyptus
urophylla have been introduced since research
results have shown them as promising alternatives
to E. camnaldilensis
Finally, mention must be made of Tephrosia
candida,a leguminous shrub which farmers are
increasingly using as a short term intercrop during
the establishment of ea plantations, providing a
source of leaf litter for the tea furrows, green
manure exported to the rice fields, seed and
firewood,
Research Experience
Project Activities
Since the inception of the Industrial Forestry
Program in the late 70s, trials have investigated a
range of species initially focused on the
commercial supply of pulpwood but later
broadening to include non-industrial species,
specifically leguminous species for firewood and
green manure production.
Research work has been plagued by protection
problems, not only from free-ranging livestock but
also illegal cutting, an increasing conce,'n for all
planting activities in the project area. This
problem, coupled with a certain lack of continuity
in research work on the non-industrial side, has
limited progress on idcntifyin MPTS suitable for
the prevailing climatic, edaphic and social
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conditions. A. mangium has been adopted as a
possible alternative to Eucalyptus spp. both for
pulpwood and fuelwood production,
particularly in areas where soil improvement is
considere important. Acacia holosc.-icca seems
promising, possibly outperformingA. Inangitt1
on the drier, degraded sites. Results on other
genera such as Albizia, Lcucaena, Sesbania and
Gliricidia are so far largely negative or at best
inconclusive.
Research work has been hampered by other
factors, including inconsistent use of inoculum,
lime and fertilizers, limited and inappropriate
selection of seed sources, and narrow
assessment techniques concentrating on tree
height and main stem diameter rather than total
biomass. This may have led to an unconscious
prejudice by research staff more familiar with
evaluating industrial species against MPTS with
multiple stems.
The range of site conditions covered by
species trials has been small, concentrating on
the mid to upper slopes of degraded hills.
Where research work has extended to more
fertile sites, towards the less densely populated
parts of the ",roject area, silvicultural care has
often been of low quality. In light of the above
problems, it would be premature to classify a
species as unsuitable when the variety of
locations (planting niches), site preparation and
tending situations have not been fully
investigated.
Research on MPTS in a managed system has
been limited to the planting of A. inangiutm and
T. candidaas elements in a soil conservation
agroforestry system involving terracing and
ditch nY techniques combined with cassava
cultivation (FTP 1989). Experience suggests
that the Acacia trees are considered a negative
influence on the cassava crop through the
effects of shading and competition for nutrients.
Tephrosia is regarded more favorably and at a
site established in 1989 farmers have extended
the original project design to include dense
sowing of the shrub both on the contour bunds
and as boundaries running down the slope
between different farmer's plots. This is an
interesting adaption, as traditionally farmers
have dug ditches to mark such divisions rather
than sow or plant woody species, as is common
for fencelincs in the homegardens.
These ditches are a considerable erosion
hazard, often collecting and channelling runoff.
This practice reflects a general lack of upland
farmers' responsibility for the impact of runoff