|Kitchen, Newell - UNIV OF MO|
|Birrell, Stuart - UNIV OF MO|
|Drummond, Scott - UNIV OF MO|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 1995
Publication Date: N/A
Technical Abstract: Electromagnetic induction (EM) measurements of soil conductivity were investigated as a means for predicting productivity variations within claypan soil fields (Udollic Ochraqualfs) and alluvial soil fields (Typic and Aquic Udipsamments, and Aeric Fluvaquents). An automated, on-the-go system combining EM sensing and Global Positioning System (GPS) was developed and used to map five fields. On claypan soil fields, EM measurements were highly correlated (r**2>0.75) with topsoil depth. Grain yield sensing for yield maps was also conducted for these same fields. When plant available water limited crop growth (1992 and 1994), EM maps predicted well major patterns of productivity. Yields in the most productive areas of the fields (greater topsoil depth) were at least double those of the lowest yielding areas (shallow or no topsoil). When moisture was ample or excessive (1993), there was very little relationship between EM and yield. For alluvial soil fields, EM readings are most highly correlated to clay and moisture content.