AEB 6933
 Spring 1995
 ANALYSIS OF ON-FARM RESEARCH

 EXERCISES

In order to reflect realistic responses, many kinds of research
whose purpose is to generate technology, must be conducted on the
kinds of farms where the technology is expected to be useful.
This can create much more variability in the data than does
research conducted on experiment stations where many factors not
included as treatments are controlled. Often, non-treatment
factors on-station are also controlled at levels high enough so
that they do not limit the potential of the variables being
tested. The result is to create environments that are much less
variable and much more productive than those found on most farms.

For researchers trained only in on-station research, the lack of
control over non-experimental variables and the resulting high
CVs can be exasperating. Many believe that "good" research
cannot be done on farms for these reasons. On the other hand, it
is becoming well recognized that farmers seldom can use,
directly, research results from experiment stations. One kind of
research results that seldom can be extrapolated successfully
from experiment stations to farms is fertility research. Because
experiment stations have been used for research, the soils have
been modified by amendments to the point they no longer resemble
the soils on most farms.

Following are a series of exercises to familiarize you with the
nature of on-farm research results. The data are taken from a
real on-farm maize fertility trial conducted by CIMMYT in Mexico.
In the trial, there were eight farms each with three replications
of all 12 treatments. Unfortunately, only the individual
treatment averages by farm are available. Furthermore, the data
on the characteristics of the individual fields where the trials
were located are not available. Nevertheless, this is an
excellent data set to work with. Therefore, these data will be
used to show a number of ways the results can be analyzed and
interpreted. The first series of exercises will look at the data
set as a whole. The second series will consider groups of farms
so that more specific recommendations can be made.


6933/FAEIEXER