| Registro completo |
| Provedor de dados: |
Scientia Agricola
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| País: |
Brazil
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| Título: |
Modeling and prediction of sulfuric acid digestion analyses data from PXRF spectrometry in tropical soils
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| 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
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| Data: |
2020-01-01
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| Ano: |
2020
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| Palavras-chave: |
Soil clay fraction
Weathering indices
Random forest
Proximal sensors
Green chemistry
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| 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.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000401402
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| Editor: |
São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
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| Relação: |
10.1590/1678-992x-2018-0132
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| Formato: |
text/html
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| Fonte: |
Scientia Agricola v.77 n.4 2020
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| Direitos: |
info:eu-repo/semantics/openAccess
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