NEAR-INFRARED REFLECTANCE SPECTROSCOPY FOR ANALYSIS OF TURF SOIL PROFILES

The evaluation of sail profiles is important in turf management. To ch aracterize soil physical and chemical properties, samples san be sent to a laboratory for analysis. This process fs time consuming and expen sive, however. The use of near near infrared reflectance spectroscopy to predict soil physical and chemical properties vies investigated usi ng turf soil profiles and compared with standard Laboratory techniques . Turf soil profiles from Michigan State University (East tensing) wer e scanned undisturbed and dried-ground with an NIRSystems 6500 monochr omator (NIRSystems, Silver Springs, MD) by analyzing four depths each 1.25 cm thick. The reflectance measurements of monochromatic light wer e made From 400 to 2500 nm at 2-nm intervals, Computer-selected sample s were analyzed in the laboratory for water content, organic matter, s and, silt, clay and some chemical properties. The explained variance r anged from 0.16 for total N to 0.93 for send, The organic matter, sand , silt, clay, P, Mg, and total N predictions were more accurate for th e undisturbed samples than for the dried-ground samples. Expanding the Michigan State University database with turf soil profiles from Penns ylvania resulted ire lower accuracies but broadened the application ra nge or Pie calibration. More research is needed to improve the predict ion accuracy of expanded databases before near infrared reflectance sp ectroscopy can be used to determine soil properties from golf peens or fairways of different locations.