117-17 Estimation of Nitrate-Nitrogen Concentration In Soil Solution Using Spectral Response.



Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Giorgi Chighladze1, Amy Kaleita-Forbes2 and Stuart Birrell2, (1)Iowa State University, Ames, IA
(2)Agricultural and Biosystems Engineering, Iowa State University, Ames, IA
Fast and reliable methods for monitoring soil nitrate-nitrogen (NO3-N) concentration is vital for reducing NO3-N losses to ground and surface water in agricultural production. In-situ measurement of nitrogen content can increase crop yield, optimize fertilizer use, and reduce environmental problems caused by high level of nitrate in water. Dielectric properties of a bulk soil have been intensively used to estimate its volumetric water content, salinity and, in some cases, NO3-N concentration employing time domain reflectometry (TDR), but no study have been done to evaluate an effect of soil nitrogen level on spectral response. Thus the goal of the work was to study the effect of NO3-N concentration on soil dielectric response at different moisture content using frequency domain techniques. We also examined the effect of global ionic concentration on the nitrogen-induced response using chloride ions as a “background” anion.
See more from this Division: S01 Soil Physics
See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)