Submitted to: Geospatial Information in Agriculture and Forestry International Conference
Publication Type: Proceedings
Publication Acceptance Date: January 12, 2000
Publication Date: N/A
Technical Abstract: With the advent of site-specific management strategies, interest has intensified in cost-effectively measuring spatially-variable soil physical and chemical characteristics. The objective of this research was to investigate the relationship of apparent soil electrical conductivity (ECa) to various soil physical and chemical properties for claypan, Mississippi delta, and deep loess hill soils. Procedures were developed using ECa to accurately and quickly map topsoil depth for claypan soils. Topsoil depth was found to affect plant-available phosphorus (P) in the claypan soil profile (r2=44). Because of this, ECa data could be used for developing more precise variable-rate P fertilizer maps. Soil ECa accurately estimated soil texture variation across Mississippi delta fields. Soil ECa accurately predicted Ca, Mg, K, and CEC for these soils. For loess hill soils, ECa variation predicted Ca and Mg well but was a poor predictor of the Bt horizon depth. With all soil ECa sensing, it is necessary to collect calibration or ground-truth data for each soil type and location, so that the factors affecting ECa at that site can be understood.