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

from on-station research, through on-farm
research managed by researchers, and finally to
farmer managed validation (van Elys 1985). With
MPTS, Atta Krah and Francis (1087) have
distinguished between types of trials to collect
technical, biological and economic data (what they
describe as type I information), and farmers' own
evaluatioa of the technology (type 2 information).
Practice
The difficulties with the above approaches to
technology testing have been described by Amir ef
al. (1989). In retrospect, it can be seen that much
FSR has been a losing battle to try and adapt
research station experimental techniques to the
on-farm situation. Often it is difficult to apply
these techniques to on-farm component technology
trials, and verification trials need a very different
approach.
Research stations are usually situated and
managed to maintain uniform and fertile
condition., which can show the yield potential of
different technologies. In more marginal and
variable upland environments, whe re mixed
cropping is widespread, yield or productivity per
area is difficult to measure at best, and may often
be an irrelevant measure of system productivity,
One answer to the problem of this variation is to
increase the replication of experiments across
farms, or to use experimental designs with one
replication per farm. Lack of landon small
holdings explains why some crop researchers have
preferred to use one replication per farm in their
experiments,
However, the resources available to many onfarm
research programs and the number of
different subjects investigated in actual practice
often mean that the number of replicatiois is not
sufficient to give reasonable estimates of yield,
With coefficients of variation of 25%, typical of
on-farm conditions, at least 10 replications are
needed to detect a 30% difference in treatment
effect at the 10% probability level. There is
commonly an interaction between site and the
treatments under test, with some treatments best at
one site, and others superior at another. If this
interaction exists, and only one rcplication per
farm is used in an experimental design, the
commonly used analysis of variance does not
provide any useful information. In this case, more
replications are needed to identify the factors
correlated with the relative performances, or to
study the stability across sites,
Similarly, difficulties in on-farm livestock
research include the small number of animals per
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farm, the mobile nature of livestock, long life
cycle, unsynchronized units, measurements of
multiple inputs and outputs, and measurement
of long-term changes in productivity (Bernsten
el al. 1985). As farmers are oftcn unwilling to
let researchers manage their valuable animals,
or manage them according to researchers'
recommendations, researchers have used unit
farms or sentinel herds where they manage
animals under conditions that approximate the
farmers' conditions as closely as possible
(ICARDA 1982; Fallada and Cook 1985).
Other solutions have included paying farmers
incentives in cash or inputs (Calub 1985;
Bunderson and Cook 1985).
Economic return is often stressed as an
important criterion in evaluating new
technology. However, if estimates of
production per hectare are imprecise, so will
estimates of return based on the production
figures. Labor data needed for an accurate
partial budget are very ard to obtain (Lightfoot
and Barker 1986). Secondary or non-market
inputs and outputs may be ignored (such as the
fodder and manuring values of a grazed fallow
in a crop rotation), the real costs of credit and
purchased inputs are often underestimated, and
the losses incurred in a bad year unaccounted.
Most economic analyses in FSR have used
short-term or annual budgeting techniques.
These are not ap propriate where bene its and
costs are spread over several years, as with
livestock and trees. Efforts have been made to
include a time dimension in economic models
for agroforcstry (Etherington and Matthews
1983), but such analyses are still rare in practice.
Furthermore, one of the principal benefits of
MPTS technologies is their sustainability. It is
only recently that economists in general have
tried to include natural resource depletion as an
economic cost, and techniques for this at the
field level are almost non-existent.
It is not surprising to find that many
apparently productive and remunerative
technologies remain unadopted. The literature
shows that research procedures and methods to
deal with these problems of technology
evaluation can be developed. However, this
sophistication requires highly trained personnel
and money. Methods resulting from well
endowed foreign aid projects or the
intrnational research centers are difficult to
adopt by resource poor government programs
on a widespread basis (Amir ct al. 1989). The
irony is that researchers have been slow to
accept the conclusion concerning research