ABSTRACT
Agricultural producers and researchers have been aware of spatial and temporal yield variability for a long time (Mercer and Hall, 1911; Lark and Stafford, 1997; Lowenberg-DeBoer and Swinton, 1997). Most farmers, when they harvest, recognize the presence of spatial variability in yield, but until recently they have been unable to precisely quantify it. Recently, new technology has become available to measure, reference, and record grain yields to document the location and magnitude of this variability. The introduction of yield monitors, yield mapping software, global positioning systems (GPS), and geographic information systems (GIS) has made it possible to measure crop grain yield within a field at a very high spatial resolution, allowing very fine and precise description of the spatial variability. If the causes of this spatial variability can be identified, then corrective action may possibly increase yield, decrease input costs in low-yielding areas, or both.
