Title: SOIL ANALYSIS USING NIR DIFFUSE REFLECTANCE SPECTROSCOPY
Chang, Chen - IOWA STATE UNIVERSITY
Mausbach, Maurice - USDA NRCS SOIL QUAL INST
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 1997
Publication Date: N/A
Near Infrared Reflectance Spectroscopy (NIRS) was evaluated as a rapid, nondestructive means for quantifying soil quality parameters. Over 800 soil samples were collected from four Major Land Resource Areas (MLRA) as part of the Natural Resource Inventory-Soil Quality Pilot Project. The samples were analyzed for 24 soil quality indicators; air-dry samples were scanned by NIRS, and then multivariate statistics were used to develop models for predicting soil quality indicators from the relfectance spectra. Preliminary analysis of samples from MLRA 105 (including portions of Iowa, Minnesota, and Wisconsin) indicates an ability of NIRS to predict texture (r**2 > 0.5), mineralizable N (r**2 > 0.5), moisture (r**2 > 0.6), total %N (r**2 > 0.7), CEC (r**2 > 0.7), respiration rate (r**2 > 0.7), total %C (r**2 > 0.7), and biomass C (r**2 > 0.8). The preliminary results suggest that NIRS is a promising technique to evaluate soil quality.