ABSTRACT
Soil is inherently variable in the physical, chemical, and biological properties that determine yield potential, a fact that complicates the identication and implementation of sustainable management practices. Historically, a lack of means to delineate and address within-eld heterogeneity has forced farmers to operate at the large scale, using the eld as a primary management unit. Soils are sampled and inputs applied to target average requirements across elds, resulting in underperforming yields in some areas and wasted inputs in others. Increasingly, farmers seek to manage land at a smaller level of resolution (site-specic management) to improve economic and ecological outcomes.
