| Texto completo | |
| Autor(es): |
Tavares, Tiago Rodrigues
;
Minasny, Budiman
;
McBratney, Alex
;
Molin, Jose Paulo
;
Marques, Gabriel Toledo
;
Ragagnin, Marcos Mantelli
;
dos Santos, Felipe Rodrigues
;
de Carvalho, Hudson Wallace Pereira
;
Lavres, Jose
Número total de Autores: 9
|
| Tipo de documento: | Artigo Científico |
| Fonte: | SOIL & TILLAGE RESEARCH; v. 245, p. 15-pg., 2024-09-18. |
| Resumo | |
This study evaluates the temporal stability of X-ray fluorescence (XRF) models for predicting plant-available calcium (av-Ca) and potassium (av-K) in a tropical agricultural field under changing soil management. Understanding this stability is crucial for advancing XRF as a quick and clean tool for soil nutrient monitoring. XRF models were tested across six sampling periods (2015, 2019, 2020, and three in 2022); lime and potash rock powder were applied before 2022 samplings to assess the XRF models response to amendments, which altered the ratio of total to plant-available nutrients (T/A ratio). We evaluated a simple model (M15) calibrated using only samples acquired in 2015 (S15), and two time-specific models (M15+SS and SS models) that incorporate samples collected at each analysis period. All models showed temporal stability when the T/A ratio was consistent, with RMSE values of 3.15-6.95 mmol(c) dm(-3) (1.91 <= RPIQ <= 4.22) for av-Ca and 1.20-1.64 mmol(c) dm(-3) (1.86 <= RPIQ <= 2.55) for av-K. However, the application of lime and potash rock powder disrupted the T/A ratio for Ca and K, reducing all models accuracy, with M15's RMSE increasing to 10.78-40.64 mmol(c) dm(-3) (0.33 <= RPIQ <= 1.23) for av-Ca and to 1.86-6.37 mmol(c) dm(-3) (0.48 <= RPIQ <= 1.64) for av-K. Although time-specific models improved accuracy compared to M15, they require frequent recalibration. Overall, XRF models can reliably predict plant-available Ca and K over time if soil management maintains a consistent T/A ratio. This study underscores the need to consider soil amendments when applying XRF models for nutrient monitoring and contributes to the theoretical basis for using XRF in agricultural management. (AU) | |
| Processo FAPESP: | 20/16670-9 - Modelagem de dados espectrais para análise da fertilidade de solos tropicais: associação das técnicas vis-NIR e XRF para a modernização dos métodos tradicionais de análise |
| Beneficiário: | Tiago Rodrigues Tavares |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 22/09678-9 - Otimização da modelagem preditiva de parâmetros da fertilidade de solos tropicais brasileiros utilizando bibliotecas espectrais de sensores XRF e vis-NIR |
| Beneficiário: | Tiago Rodrigues Tavares |
| Modalidade de apoio: | Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado |