TY - JOUR
T1 - Advances in Tropical Soil Characterization via Portable X-Ray Fluorescence Spectrometry
AU - SILVA, Elen A.
AU - WEINDORF, David C.
AU - SILVA, Sérgio H.G.
AU - RIBEIRO, Bruno T.
AU - POGGERE, Giovana C.
AU - CARVALHO, Teotonio S.
AU - GONÇALVES, Mariana G.M.
AU - GUILHERME, Luiz R.G.
AU - CURI, Nilton
N1 - Publisher Copyright:
© 2019 Soil Science Society of China
PY - 2019/8
Y1 - 2019/8
N2 - Portable X-ray fluorescence (pXRF) spectrometers can be used to determine the elemental composition easily, rapidly, and without using chemical reagents, which is very important for tropical regions due to the lack of detailed soil characterization data. Moreover, pXRF data can be used to predict the results of more expensive, time-consuming, and conventional laboratory analyses. This study sought to determine the elemental composition of various soil profiles using pXRF. Two operational modes (Trace Mode and General Mode) and two scanning time (30 and 60 s) were assessed to determine their effects on the correlation of pXRF dataset with respect to conventional inductively coupled plasma (ICP)-optical emission spectrometry analysis. This relationship has been reported in previous studies, however, few studies were performed on tropical soils, which are unique. Furthermore, such relationships establish the viability of developing prediction models directly from pXRF data. Linear regression was applied to develop calibration models for the prediction of ICP analysis results and exchangeable and available elemental contents based on pXRF data. High coefficients of determination (R2) were obtained for Ca (0.87), Cu (0.90), Fe (0.95), Mn (0.85), Cr (0.95), V (0.72), and Ni (0.90), with adequate validation. Statistically significant results were not found for Al, K, Zn, Ti, and Zr. The models predicting the exchangeable Ca based on the total Ca from pXRF reached an R2 of up to 0.85. Operational modes influenced the pXRF results. Our results illustrate that pXRF holds great promise for tropical soil characterization and the development of prediction models, justifying the need for larger-scale studies in tropical countries worldwide.
AB - Portable X-ray fluorescence (pXRF) spectrometers can be used to determine the elemental composition easily, rapidly, and without using chemical reagents, which is very important for tropical regions due to the lack of detailed soil characterization data. Moreover, pXRF data can be used to predict the results of more expensive, time-consuming, and conventional laboratory analyses. This study sought to determine the elemental composition of various soil profiles using pXRF. Two operational modes (Trace Mode and General Mode) and two scanning time (30 and 60 s) were assessed to determine their effects on the correlation of pXRF dataset with respect to conventional inductively coupled plasma (ICP)-optical emission spectrometry analysis. This relationship has been reported in previous studies, however, few studies were performed on tropical soils, which are unique. Furthermore, such relationships establish the viability of developing prediction models directly from pXRF data. Linear regression was applied to develop calibration models for the prediction of ICP analysis results and exchangeable and available elemental contents based on pXRF data. High coefficients of determination (R2) were obtained for Ca (0.87), Cu (0.90), Fe (0.95), Mn (0.85), Cr (0.95), V (0.72), and Ni (0.90), with adequate validation. Statistically significant results were not found for Al, K, Zn, Ti, and Zr. The models predicting the exchangeable Ca based on the total Ca from pXRF reached an R2 of up to 0.85. Operational modes influenced the pXRF results. Our results illustrate that pXRF holds great promise for tropical soil characterization and the development of prediction models, justifying the need for larger-scale studies in tropical countries worldwide.
KW - elemental composition
KW - exchangeable Ca
KW - inductively coupled plasma
KW - operational mode
KW - prediction models
KW - scanning time
KW - soil analysis
KW - total elemental content
UR - http://www.scopus.com/inward/record.url?scp=85069601435&partnerID=8YFLogxK
U2 - 10.1016/S1002-0160(19)60815-5
DO - 10.1016/S1002-0160(19)60815-5
M3 - Article
AN - SCOPUS:85069601435
SN - 1002-0160
VL - 29
SP - 468
EP - 482
JO - Pedosphere
JF - Pedosphere
IS - 4
ER -