The Potential of Near-infrared Spectroscopy to Predict Soil Nutrient Contents Based on Soil Color
by Piyamas Khammao, Wutthida Rattanapichai, Roongroj Pitakdantham, Poonpipope Kasemsap and Kannika Sajjaphan
Journal
ASEAN Journal of Scientific and Technological Reports (AJSTR)
Volume
27
Issue
5 (September – October 2024)
Publisher
Thaksin University
ISSN
2773-8752 (Online)
Abstract
Near-infrared spectroscopy (NIRs) analysis in laboratory-based settings has the potential to predict soil elements. The aim was to explore the effects of soil color on the prediction of total nitrogen (N), available phosphorus (P), and extractable potassium (K) contents using near-infrared spectroscopy in the range of 1000–2500 nm. Two hundred forty soil samples were collected from a paddy field in northeast Thailand. We divided the soil samples based on soil color using the Munsell color chart to construct a model to predict nutrient contents based on soil color. Regression models for soil nutrient contents were developed using partial least squares regression (PLSR) models. The best predictions were obtained for N (R² = 0.87, RMSE = 0.131), P (R² = 0.87, RMSE = 7.713) and K (R² = 0.77, RMSE = 14.944). This research demonstrates the viability of employing Near-Infrared spectroscopy (NIRs) as a reasonable method for predicting soil nutrient contents.