Data/hora: 13/06/2024 03:40:42

Provedor de dados: | 63
País: | Brazil
Título: | Modeling and prediction of sulfuric acid digestion analyses data from PXRF spectrometry in tropical soils
Autores: | Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Poggere,Giovana Clarice; Pádua Junior,Alceu Linares; Gonçalves,Mariana Gabriele Marcolino; Guilherme,Luiz Roberto Guimarães; Curi,Nilton.
Data: | 2020-01-01
Ano: | 2020
Palavras-chave: | Soil clay fraction; Weathering indices; Random forest; Proximal sensors; Green chemistry.
Resumo: | ABSTRACT Sulfuric acid digestion analyses (SAD) provide useful information to environmental studies, in terms of the geochemical balance of nutrients, parent material uniformity, nutrient reserves for perennial crops, and mineralogical composition of the soil clay fraction. Yet, these analyses are costly, time consuming, and generate chemical waste. This work aimed at predicting SAD results from portable X-ray fluorescence (pXRF) spectrometry, which is proposed as a “green chemistry” alternative to the current SAD method. Soil samples developed from different parent materials were analyzed for soil texture and SAD, and scanned with pXRF. The SAD results were predicted from pXRF elemental analyses through simple linear regressions, stepwise multiple linear regressions, and random forest algorithm, with and without incorporation of soil texture data. The modeling was developed with 70 % of the data, while the remaining 30 % was used for validation through calculation of R2, adjusted R2, root mean square error, and mean error. Simple linear regression can accurately predict SAD results of Fe2O3 (R2 0.89), TiO2 (R2 0.96), and P2O5 (R2 0.89). Stepwise regressions provided accurate predictions for Al2O3 (R2 0.87) and Ki - molar weathering index (SiO2/Al2O3) (R2 0.74) by incorporating soil texture data, as well as for SiO2 (R2 0.61). Random forest also provided adequate predictions, especially for Fe2O3 (R2 0.95), and improved results of Kr - molar weathering index (SiO2/(Al2O3 + Fe2O3)) (R2 0.66), by incorporation of soil texture data. Our findings showed that the SAD results could be accurately predicted from pXRF data, decreasing costs, time and the production of laboratory waste.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000401402
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/1678-992x-2018-0132
Formato: | text/html
Fonte: | Scientia Agricola  v.77 n.4 2020
Fonte: | info:eu-repo/semantics/openAccess