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OFT key1995 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:

  1. Proper design and layout of the experiment.
  2. Replication of the treatment comparisons.
  3. Accurate measurement of yield and other factors of interest from the individual treatment plots.
  4. 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.

 
                         
                         
                         
 

Contact us: Hans Kok, (208)885-5971 | Accessibility | Copyright | Policies | WebStats | STEEP Acknowledgement
Hans Kok, WSU/UI Extension Conservation Tillage Specialist, UI Ag Science 231, PO Box 442339, Moscow, ID 83844 USA
Redesigned by Leila Styer, CAHE Computer Resource Unit; Maintained by Debbie Marsh, Dept. of Crop & Soil Sciences, WSU