Open AccessTotal Nitrogen Estimation of Paddy Soil Using Visible and Near Infrared Spectroscopy
Author(s) -
Siti Noor Aliah Baharom,
Jusnaini Muslimin,
Badril Hisham Abu Bakar,
Muhammad Zamir Abdul Rasid,
Ramlan Ismail,
Mohd Zamri Khairi Abdullah,
Muhammad Shukri Hassan
Publication year - 2021
Publication title -
advances in agricultural and food research journal
Language(s) - English
Resource type - Journals
ISSN - 2735-1084
DOI - 10.36877/aafrj.a0000232
Subject(s) - partial least squares regression , near infrared spectroscopy , calibration , nitrogen , soil test , spectroscopy , coefficient of determination , precision agriculture , environmental science , soil fertility , analytical chemistry (journal) , soil science , chemistry , mathematics , soil water , environmental chemistry , statistics , agriculture , optics , ecology , physics , organic chemistry , quantum mechanics , biology
The current soil nutrient estimation method is laborious, repetitive, time-consuming and costly, making it less efficient for large-scale soil fertility assessment in precision agriculture practice. This paper discussed the feasibility of visible and near-infrared (Vis-NIR) spectroscopy as an alternative method for rapid measurement of total nitrogen in the soil, which is more efficient for a huge paddy field area. For this purpose, Vis-NIR reflectance spectra (350 – 1750 nm) were acquired on 200 soil samples using spectrometers. Partial Least Squares Regression (PLSR) with full (leave-one-out) cross-validation was used to develop the calibration model between the Vis-NIR soil spectra and the total nitrogen obtained by chemical analysis in laboratory. The coefficient of determination (R2val) and residual prediction deviation (RPD) of the developed calibration model for total nitrogen (Ntot) was 0.78 and 1.86, respectively. The predicted total nitrogen map generated based on the Vis-NIR spectroscopy was comparable with the laboratory analysis’s measured map. This result indicates that the Vis-NIR infrared spectroscopy is the potential to be used for total nitrogen estimation in soil.