Open AccessMonitoring Mineral-Associated Organic Matter in Tropical Pastures using Near Infrared Spectroscopy
Author(s) -
Felipe Bachion de Santana,
André de Mello e Souza,
Fabiano de Carvalho Balieiro,
Mirelly Mioranza,
Renato de Aragão Ribeiro Rodrigues,
Ronei J. Poppi
Publication year - 2021
Publication title -
brjac brazilian journal of analytical chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.131
H-Index - 6
eISSN - 2179-3433
pISSN - 2179-3425
DOI - 10.30744/brjac.2179-3425.ar-10-2021
Subject(s) - partial least squares regression , soil carbon , fraction (chemistry) , soil organic matter , environmental science , fractionation , greenhouse gas , soil test , greenhouse , combustion , soil science , chemistry , soil water , mathematics , statistics , agronomy , geology , oceanography , organic chemistry , biology
In order to confirm that the mitigation of greenhouse gas emissions could indeed be achieved by farmers, determinations of soil organic carbon (SOC) in total and stabilized fractions are essential, proving the effectiveness of the sustainable practices adopted by the farmer. In this sense, this study proposes an analytical methodology based on near infrared spectroscopy (NIRS) and partial least squares regression (PLSR) as an alternative for the measurement of stabilized and total soil organic carbon (SOC) in agricultural production systems. A set of 122 samples of four different land uses were sampled and the stabilized and labile SOC content were determined by the dry combustion method. In order to eliminate the extra step regarding soil fractionation to determine the stabilized SOC content, this study investigated different strategies to build the regression model based on partial least squares regression for the determination of the stabilized SOC from the total soil fraction. Two strategies presented the same accuracy as the reference method used to determine the stabilized SOC content in stabilized fraction, with root mean square error in validation of 1.47 g/dm3. These results indicate that both strategies proposed can determine simultaneously the total and stabilized SOC from the total soil fraction, thus eliminating the extra sample preparation.