Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/29/2003
Publication Date: 11/4/2003
Citation: WOODBURY, B.L., EIGENBERG, R.A., NIENABER, J.A. VERIFYING SOIL CROP DYNAMIC MEASURED BY ELECTROMAGNETIC INDUCTION USING TIME DOMAIN REFLECTOMETRY. MEETING ABSTRACT. Soil Science Society America Annual Meeting, Denver, Colorado. CD-ROM S11-woodbury128185. 2004. Interpretive Summary:
Technical Abstract: Traditional methods to measure soil-crop nutrient dynamics cannot adequately address short-term (i.e. 1 hour) changes or inherent soil spatial variability. Electromagnetic induction (EMI) has been used to measure spatially variable apparent bulk soil conductivity but interpretation of results can be complicated. The objectives of this study are to quantify short-term dynamics of soils using TDR and verify similar dynamics measured by EMI. Thirteen, 12.5 cm TDR probes were placed in an irrigated corn silage field plot to evaluate the upper 15 cm of the soil profile. The field plot has received nine years of treatments which include commercial fertilizer (NCK), manure (MN) and compost (CN) at the required nitrogen rate. Each rate has a fall cover, no-cover, and no-crop treatments. Soil conductivity measured by TDR and EMI in the CN, no-crop treatment demonstrated little seasonal variability. ECEMI were consistently greater than ECTDR indicating some ions had leached below TDR probes. Both EC methods demonstrated similar seasonal trends in the CN, crop treatment. Decreases in EC from day 160 to 200 were more pronounced for the TDR than for the EMI. It appears that early crop development removed nutrients near the surface which impacted the reading from ECTDR more than the ECEMI. Additional comparisons and analysis of data will be included.