Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2003
Publication Date: 11/6/2003
Citation: LAIRD, D.A., CHRISTY, C. ON-THE-GO NEAR INFRARED REFLECTANCE SPECTROSCOPY ANALYSIS OF SOILS. ASA-CSSA-SSSA ANNUAL MEETING ABSTRACTS. 2003. CD-ROM. MADISON, WI.
Technical Abstract: Soil sensors are needed for precision farming, carbon sequestration assessment, and soil quality assessment. We tested the soil sensing capabilities of a prototype of a field mobile, on-the-go, Near Infrared Reflectance (NIR) spectrometer system built by Veris Technologies, Inc. (Salina, KS). The system consisted of an optical system embedded in a steel shank, which can be pulled through the soil behind a tractor at a controlled depth. The system also includes a GPS unit and a computer that accumulates both the spectral and GPS data. The system was tested in two agricultural fields by collecting real time spectra (20 spectra per second, 350 to 1700 nm) along 30 or 37 transects within the fields. Approximately 150 soil samples were collected from each field at known locations from the smear face left by the steel shank at the base of the furrow. The soil samples were analyzed for moisture content, organic C, total N, pH, SMP-buffer pH, and ECEC by sum of ammonium acetate extractable Ca, Mg, K, Na, and Al. Multivariate partial least squares calibration models were developed using The Unscrambler (Camo Process, Inc.) to relate the measured soil properties to the field collected spectra. The results demonstrate the ability of the system to distinguish unique management zones (low, medium, and high) for N-fertilization, K-fertilization, and lime requirement. The system also provides a means of mapping organic C, total N, and ECEC of agricultural fields.