Spatial variability within fields has been demonstrated by soil testing results and crop yield differences. Crop responses vary greatly in uniformly managed fields because of soil and landscape differences. An understanding of variation within the landscape requires a means of mapping spatially variable parameters. Existing traditional techniques of spatial statistics do not account for the spatial correlation between observations and take little account of gradual change, either from one soil class to another or within any one class. Differently, geostatistics treats variables as continua in a joint attribute and geographic space.