Delineating Site-Specific Management Units with Proximal Sensors

Abstract

Conventional farming manages fields uniformly with no consideration for spatial variation. This causes reduced productivity, misuse of finite resources (e.g. water and fertilizers) and detrimental impacts on the environment. Site-specific management units (SSMUs) have been proposed as a way of resolving the spatial variation of various factors (i.e. soil, climate, management, pests, etc.) that affect variation in crop yield. Mobile proximal sensors, such as those used to measure apparent soil electrical conductivity (ECa), can be used to characterize the spatial variation of soil properties that affect crop yield. This Chapter provides an overview of the work by the authors that has led to the delineation of SSMUs based on edaphic and anthropogenic properties, with particular emphasis given to the geostatistical techniques needed to direct soil sampling to characterize the spatial variation. The approach uses geospatial proximal sensor measurements to locate the positions of soil samples to characterize the variation in soil properties that affect crop yield within a field. A crop yield response model is developed and maps of SSMUs based on soil and crop yield information are produced. The methodology for delineating SSMUs can be used whenever the proximal sensor measurements correlate with yield. Maps of SSMUs provide the vital information for variable-rate technology (e.g. site-specific fertilizer and irrigation water application).