01/03/2020
Mobile XRF instrument setup with handheld XRF and XRF sensor for measuring moving samples (left) and rotating sample plate with track (right)

Mobile XRF instrument setup with handheld XRF and XRF sensor for measuring moving samples (left) and rotating sample plate with track (right)

Source: BAM, Division Process Analytical Technology

Within the framework of precision agriculture, the determination of various soil properties is moving
into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive
X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. EDXRF enables rapid and simultaneous multi element analyses with little or no sample preparation and is an appropriate method for future real time measurements in the field. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set. Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil
samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged
deviation and PLSR should therefore be preferred.

Multivariate chemometrics as a key tool for prediction of K and Fe in a diverse German agricultural soil-set using EDXRF
Dominique Büchele, Madlen Chao, Markus Ostermann, Matthias Leenen & Ilko Bald
published in Scientific Reports, Vol. 9, pages 17588, 2019
BAM, Division Process Analytical Technology