Submitted to: Applied Statistics In Agriculture Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/26/2005
Publication Date: 4/26/2005
Citation: Meek, D.W., Singer, J.W. 2005. An example of developing covariates for problems in precision agriculture. Applied Statistics In Agriculture Conference Proceedings. p. 270-278.
Technical Abstract: Methodology for precision agriculture is, perhaps, too focused on methods that allow for spatial correlation in the ANOVA (Analysis of variance) error term. While sound inference about differences between local yields can be computed, no understanding of what is driving these differences is achieved. A completely general form for a spatial model can include suitable covariates. Most research in precision agriculture includes gathering a variety of site-specific information. Through the presentation of the analysis of data from a published soybean (Glycine max (L.) Merr.) study, one specific type of covariate is developed - a duration index for soybean canopy light interception over the growing season. The relationship of the index to grain yield is reasonably well determined (R2=0.82). We, therefore, suggest that the quest for modeling an appropriate covariate or covariates is primary. Treating spatial variation by other methods should only be used when the quest has failed.