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

(1984). The International Council for Research in
Agroforestry (ICRAF) has established an MPFS
database containing some 1,400 entries of 650
MPTS species with agroforestry potential (von
Carlowitz 1987).
It is unnecessary to stress that the task of
effectively evaluating and improving this range of
potentially useful MPTS on a national, regional
and global scale is daunting. Furthermore, there is
now a race against time as the current rapid rate of
deforestation in tropical countries is threatening
many potentially useful MPTS with extinction.
Overwhelming as the research agenda may sound,
it is suggested that concentration on several issues
could yield valuable results in the immediate and
distant future. These would include the
quantification and prioritization of the farmers'
present and future needs for a diversity of MPTS
products and services; farmer-based surveys on
MPTS species and trait preferences; botanical and
gene pool explorations; and ea-situ conservation of
endangered MPTS species.
Rationalizing the Specific Roles of MPTS
on Farms
Many workers have recognized the urgent need
to evaluate and improve MPTS for community
forestry and agroforestry. The),have responded to
this need by quickly establishing species and
provenance trials along time-tested forestry
research lines. Some of this effort has assumed
regional and international dimensions such as the
Oxford Forestry Institute coordinated international
trials, the Australian Centre for International
Agricultural Research (ACIAR) trials, the
Forestry, Fuelwood Research and Development
(F/FRED) Project Irials, the Nitrogen Fixing Tree
Association (NFI'A) trials and the Agroforestry
Research Networks for Africa trials. While very
valuable data and information is resulting from
such efforts, its direct applicability to the small
farm situation may be rather limited due to the fact
that the trials are not always sufficiently
rationalized on current farming systems.
An approach to rationalizing specific roles of
MPTS on farms and the attendant research
priorities has been proposed by ICRAF (1983).
This approach, diagnostic and design
methodology, involves an interdisciplinary systems
appraisal of the needs of the farmer and the
potential roles MPTS could play in satisfying those
needs. Based on the identified MPTS roles on
farms, evaluation and improvement research
focuses on several species which have the highest
potential to yield the desired results.
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For example, out of such an interdisciplinary
appraisal in an area of eastern Africa with a
defined food crop farming system in a defined
agro-climatic zone (bi-modal rainfall highlands),
it was determined that the greatest needs for
MPTS are as dry season fodder
suppllementation, and soil erosion control and
fertility enhancement. The macro-analysis was
then supplemented by MPTS-specific
micro-analyses which incorporated such aspects
as farmers' preferences to guide the researcher
to species of the highest research priority.
Beyond recognizing the potential roles of
MPTS in farming systems, identified specific
attributes of MFTS worthy of evaluation and
improvement included soil improvement such as
total litter/mulch production, litter/mulch
quality, rooting habits, and nitrogen fixation
potential; fodder production including total
annual fodder production, dry season fodder
production, palatability, digestibility, and animal
performanre; and fuelwood/pole production to
include tot,i wood production, bole form, and
wood density. Based on these analyses,
researchers were able to work with a
manageable number of MPTS species for the
entire zone.
Ecological and Farming System MPTS
Adaptation
Climatic and edaphic adaptation of MPTS
for small farm use should be evaluated along the
same general lines as for plantation forestry.
However, special emphasis should be given to
the following aspects:
- adaptation to seasonal climatic regimes. If,
for example, the purpose of introducing
MPTS is dry season fodder supplementation
then the emphasis should be on MPTS
provenances which are well adapted to dry
season growth and which produce maximum
amounts of fodder during this particular
season;
- adaptation and optimal response to
external soil inputs such as fertilizers and
manures; and
- the ability to extract nutrients efficiently
from nutrient deficient soils by root
associations such as mycorrhizae and proteod
root masses.
In addition to adaptation, tree growth
characteristics must be carefully evaluated,