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 1995
Test Results
Introduction
On-farm tests
enable farmers to explore and evaluate various production options
using an accurate low risk tool. This publication summarizes many
of the on-farm tests conducted by growers in the Pacific Northwest
during the 1994-95 crop year. Some test reports also contain results
of experiments carried out over more than one year. Repeating tests
over years helps to establish more reliable results because yearly
climatic variations usually influence the effects of most treatments.
Most of these
field tests were associated with the STEEP II on-farm testing project.
STEEP II is a cooperative research and education program in Idaho,
Oregon and Washington focused on developing effective and profitable
conservation farming systems for the region. University extension
specialists, county extension agents, and other agriculture industry
personnel involved with the STEEP II on-farm testing project provided
guidance and support to growers conducting the tests. For more information
about the project or on-farm testing, contact your local extension
office, or any of the investigators listed on the first page of
this report.
You will find
many different on-farm test topics in this report. The diversity
of experiments reflects the diverse kinds of management questions
growers face in their farming business. Some examples of the on-farm
test topics include: tillage equipment, drills, fertilizers applications,
seed treatments, crop cover, rotations, varieties, rates of herbicides,
fungicides, tillage practices, biosolids, micronutrients, and methods
of returning Conservation Reserve Program (CRP) to crop production.
The use of
some basic experimental methods is critical to achieving accurate
results with on-farm testing. Because of the natural variation that
exists within every field, an important step is to replicate your
treatment comparisons. Statistical analysis of the results of replicated
tests can then be used to separate the effects of natural field
variability from the treatment effect. Associated with each of the
data tables in these on-farm test reports there is an ALSD (5%)@
which stands for Aleast significant difference at a 5% probability
level.@ The LSD is used to determine if the treatments are statistically
different from one another. If the difference between two treatment
averages is greater than the LSD shown, there is a 95% probability
that the difference is due to the treatments and not to natural
field variability. To help illustrate this variability, data collected
from each replication of the test are included in most of the reports.
Final decisions regarding management options evaluated in an on-farm
test should also be based on the grower=s experience, economics,
interactions with other managements practices and more than one
year of tests.
Designing
an On-farm Test
The on-farm
tests presented in this publication are designed to compare the
performance (yield, stand establishment, protein, water infiltration,
weed populations, or other criteria) of two or three different crop
management practices, or Atreatments.@ An on-farm test can be as
simple as a comparison of fertilizer rates or more complex, with
comparisons of different crop rotations and production systems.
On-farm testing
methods involve:
- Proper design
and layout of the experiment.
- Replication
of the treatment comparisons.
- Accurate
measurement of yield and other factors of interest from the individual
treatment plots.
- Analysis
and interpretation of results using accepted statistical procedures.
Using these
on-farm testing methods, growers can achieve experimental precision
comparable to those of intensive university research trials. Reliable
results will enable farming practices to progress to even greater
productivity efficiencies and resource protection.
Designing a
test that will produce accurate, conclusive information requires
replicated, side-by-side comparisons. This is the only way to distinguish
performance differences caused by the treatments from differences
due to natural field variability. Extensive research in the Inland
Pacific Northwest has shown that long, narrow, side-by-side strips
replicated at least four times can produce a very accurate comparison.
Although, there have been many successful tests with four replications
of 300 feet strips, strip lengths of 750 feet or longer strips will
generally produce more accurate results. Four replications are recommended,
but more replications could be worthwhile if the comparison might
produce small differences or if the differences are very important
economically. Using more replications in an experiment increases
the opportunity to more precisely estimate the treatment effect,
or response. It is difficult to understand the importance of having
adequate replication until you have had some experience trying to
draw conclusions from data with only two or three replications --
when the differences in the responses to the treatments often need
to be quite large before they are statistically significant. With
the availability of portable weighing equipment, 8 to 12 strips
(4 replications of 2-3 treatments) can usually be harvested in less
than three hours.
After deciding
what the treatments are going to be, pick locations in the field
where you can place the treatments in long, side-by-side strips.
All strips in a replication should have an equal chance to perform
well, in your best judgment. For example, do not place one strip
on flat ground and the other on a hill slope. Avoid field borders
and corner areas where overlaps of fertilizer, seeding, herbicides
or extra tillage passes might occur. Flip a coin to decide which
treatment goes in which strip. Repeat this for each replication.
The replications may be placed next to each other or in separate
parts of the field.
In some on-farm
tests, the strips may need to be marked at specific widths using
flags or stakes so that different treatments can be established
in the proper places. If treatments effects on surface runoff or
erosion need to be compared, landscape-specific trials need to be
designed so each pair of treatment extends down slope from the top
of the field. It is recommended that help be sought from someone
with experience in designing this type of test.
Be sure to
adequately mark the plots so you can locate them later in season!
Measuring from reference points or stakes on field borders can also
help to reestablish plot locations for harvest or other data collection.
When measurements
are made, such as stand counts or yield, record them separately
for each replication of each treatment. The data can then be analyzed
statistically using a hand calculator and step-by-step formulas.
An easy-to-use statistics computer program called AGSTATS (for IBM
compatible computers) is available from OSU for analyzing the results
of simple field trials. To request a copy, send a blank 3 2 inch
diskette and return postage mailer, or send a $5 check payable
to the Ag Research Foundation, addressed to Russ Karow, Extension
Agronomist, Crop Science Building 107, Oregon State University,
Corvallis, OR 97331-3002. Assistance in analyzing the test data
is also available through your county extension agent. Even without
statistics a lot can be learned from observation of different treatments
to see if one is consistently better than the other in each of the
replications.
Before you
start your first replicated on-farm test, ask for assistance in
designing and conducting on-farm tests from your county extension
agent or others experienced with on-farm testing. Effectively designed
and conducted, on-farm tests can provide growers with an accurate,
low-risk tool for evaluating new production options and making successful
management decisions.
On-Farm Testing
Resources
1992
Pacific Northwest On-Farm Test Results. S. B. Wuest, B.C.
Miller, R. J. Veseth, S. O. Guy, D.J. Wysocki and R. S. Karow.
1992. Department of Crop and Soil Sciences Technical Report 92-4,
Washington State University, Pullman, WA
1993
Pacific Northwest On-Farm Test Results. S. B. Wuest, B.C.
Miller, R. J. Veseth, S. O. Guy, D.J. Wysocki and R. S. Karow.
1993. Department of Crop and Soil Sciences Technical Report 94-1,
Washington State University, Pullman, WA
1994
Pacific Northwest On-Farm Test Results. S. B. Wuest, B.C.
Miller, R. J. Veseth, S. O. Guy, D.J. Wysocki and R. S.
Karow. 1994. Department of Crop and Soil Sciences Technical Report
95-1, Washington State University, Pullman, WA
....The above
publications summarize the results of the on-farm tests conducted
in previous years. Order from the WSU Crop and Soil Sciences
Extension Office (509-335-2915)
On-Farm
Testing: A Grower=s Guide. B. Miller, E. Adams, P. Peterson
and R. Karow. 1992. Washington State University Cooperative
Extension EB1706.
A guide to
designing and carrying out OFT. Includes forms for record keeping.
20 pages, $1.00. Order from the WSU Cooperative Extension Bulletin
Office (509-335-2999)
On-Farm
Test Record Form. S. B. Wuest, B.C. Miller, R.
J. Veseth, S. O. Guy, D.J. Wysocki and R. S. Karow. 1995. Pacific
Northwest Extension Bulletin PNW 487.
A convenient
form to simplify planning and record keeping for on-farm tests.
8 pages, $1.50. Available at county extension offices in
the Northwest, or order from the WSU Cooperative Extension Bulletin
Office (509-335-2999).
Using
an On-Farm Test for Variety Selection. S. B. Wuest, B.C.
Miller, R. J. Veseth, S. O. Guy, D.J. Wysocki and R. S.
Karow. 1995. Pacific Northwest Extension Bulletin PNW 486.
A detailed
reference on how to plan, install on-farm test for variety selection.
6 pages, $1.50. Available at county extension offices in the Northwest,
or order from the WSU Cooperative Extension Bulletin Office (509-335-2857)
AGSTATS. R. Karow, D. Lazarri, and R.L. Fowler. 1988. Data Analysis Program.
Oregon State University, Corvallis, OR.
An easy-to-use
statistics computer program (for IBM compatible computers) is
available from OSU for analyzing the results of simple field trials.
To request a copy, send a blank 32 inch diskette and return postage
mailer, or send a $5 check payable to Ag Research Foundation,
addressed to Russ Karow, Extension Agronomist, Crop Science Building
107, Oregon State University, Corvallis, OR 97331-3002.
On-Farm
Testing References
Johnson, J.J.,
B.C. Miller, J.R. Alldredge, and S.E. Ullrich. 1994. Using single-replicate
on-farm tests to enhance cultivar performance evaluation. Journal
of Production Agriculture 7:13-14, 76-80.
Wuest, S.B.,
B.C. Miller, J.R. alldredge, S.O. Guy, R.S. Karow, R.J. Veseth,
and D.J. Wysocki. 1994. Increasing plot length reduces experimental
error in on-farm tests. Journal of Production Agriculture 7:169-170,
211-215.
Wuest, S.B.,
S.O. Guy, L.J. Smith, and B.C. Miller. 1995. On-farm tests as a
tool for extension programming. Journal of Extension Feature Article:
33(4): 1-4. |
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