Validating a Digital Soil Map with Corn Yield Data for Precision Agriculture Decision Support
957 Managing variability in crop productivity is a complex challenge due to fundamental interactions between genetic potential (G) biophysical environments (E) and management (M) activities (G E M) (Ortega and Santibanez, 2007) The components of G E M are multidimensional and vary across space and time. A key PA approach taken to simplify spatial complexity is the division of fields into subfield areas, often called management zones (MZs) that are managed individually with respect to important agronomic decisions (Fridgen et al. 2004; Schepers et al. 2004; Kitchen et al. 2005; Cox and Gerard, 2007; Derby et al. 2007; Thorp et al. 2008; Moshia et al. 2014) Digital soil mapping has similar goals for partitioning the spatial variability of fundamental soil landscape factors into more uniform delineations (McBratney et al. 2003; Roberts et al. 2012) Additionally, DSM products can be used as a basis for MZs (McBratney and Minasny, 2007; Triantafilis et al. 2009; Omran 2012; Davatgar et al. 2012) Several methodologies have been introduced for developing DSMs based on soil or geophysical terrain attributes (Moore et al. 1993; Johnson et al. 2003; Kitchen et al. 2005; Mulla 2013) however, less work has been done to validate their success in PA (Bishop et al. 2001; Whelan and McBratney 2000) Therefore, methods for developing and validating DSMs across diverse agricultural crop production regions are needed. One common approach for creating MZs has been to use public soil maps, such as the NRCS SSURGO database (Ortega and Santibanez, 2007; Soil Survey Staff 2014) Th e resolution needed to develop MZs for PA, however, exceeds that typically found in SSURGO products (Robert 2002; Zhu et al. 2013) Th e challenge is that traditional soil survey methods, like SSURGO, are diffi cult and expensive to apply at fi ne resolutions because physical observations of mapped locales are required for quality control (Grunwald et al. 2011) Th us, the low resolution, publicly available DSM products have limited value in PA (Van Alphen and Stoorvogel 2000; McBratney et al. 2005; Miller 2012; Landrum et al. Validating a Digital Soil Map with Corn Yield Data for Precision Agriculture Decision Support