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.standard statistical procedures were followed" implies all of the above even if the researcher (or farmer) did not really understand the statistical thinking very well.
Many of these criteria are not recognized nor understood by most farmers. They prefer
trials that are fairly close to the home farm or under similar conditions or both, that have plots large enough to use commercial equipment, that show visible differences among treatments, that can reduce costs or increase profits, or that solve a constraint that was already perceived on their farm or in the area (Francis, 1986a). In the real world we encounter comparisons from one year to the next, from one field to another, from one farm to a neighbor's, or among strips in a field that have different treatments (eg. varieties or hybrids) with no replication. Although these comparisons do not meet the criteria recognized by the scientist to qualify as credible or valid research, the results are no less meaningful to many farmers. We do find that careful explanation in an extension meeting of some of the criteria used by researchers, for example replication and randomization of treatments, leads to a fairly quick understanding of the need for these methods and the importance for repeatability of the experience.
Are these two definitions of "research" mutually exclusive, or is there some middle ground where farmer creativity, land, and resources can be utilized for credible on-farm research? Over the past several years, there has been substantial work on large plots with few treatments, replication and randomization, and standard statistical analysis. Long strip designs used to compare two or three treatments were described by Thompson (1990), and are currently being used by a number of the members of the Practical Farmers of Iowa, among other groups. Rzewnicki et al. (1988) summarized these trials from Iowa as well as some from farms and from experiment stations in Nebraska. With plots that ranged from 200 to 1200 feet long by four to eight rows wide and three to six replications. per-treatmente they.foundcoefficients of variation from less- than 1.0 to about 10 percent; the CVs-were frequently less than five percent. Practical researchers who are familiar with the variation in most field experiments find these levels very acceptable.
How is it possible that such large plots have low CVs7 Although we are only now testing these hypotheses by comparing large and small plots from the same field (Shapiro et al., 1989, 1990), it appears that a long and narrow plot goes across a range of variability in the field. A plot located adjacent with the same dimensions crosses the same gradient, and at any one point there is relatively less difference between the strips than there is across the gradient in each long plot. Thus the potential exists for planting contrasting treatments side by side, allowing use of full sized commercial equipment and having a highly visible comparison, while still meeting the requirements of replication and randomization. This would appear to be one option for an individual farmer to collect credible data for one site in one year, and use standard statistical techniques such as analysis of variance, t-test, or paired comparisons to evaluate the trials. In one set of comparisons, the Clay County Corn Growers in Nebraska planted maize hybrids in unreplicated strip plots in four areas in the county, with similar conditions and the same hybrids in each test. Analyzed with farms as replications, there were CVs from three-to four percent over the five years of the tests (Rzewnicki et al., 1988). This opens the possibilities for individuals or groups of farmers to work in a cooperative research network and to develop-a credible set of comparisons for.use by them and. by others. Each farmer becomes a part of the research and extension network, since these plots are used for field tours and the data for extension meetings before the next planting season.
Results from these large replicated or unreplicated trials in Nebraska represent one approach that can be taken by farmers in a highly mechanized, large farm situation. It is a challenge to the practical researcher or applied extension person to explain the basic characteristics of the trials, and to work directly with farmers in developing the research agenda.