2020 Volume 69 Issue 12 Pages 685-692
We applied wavelength-dispersive XRF (WDXRF) analysis to estimate the fertilizer contents in soil from a single field. Each soil sample was just made into a pellet and measured by WDXRF combined with the Fundamental Parameters approach with good precision within 9 min. Ninety-nine soil samples were collected from a field of approximately 10 ha in the Spring and 51 soil samples were collected in the Fall to determine the fertilizer contents in the soil, i.e., the quantity of phosphorus, potassium, magnesium, and calcium, through WDXRF and conventional analytical methods. The results for phosphorus, potassium, and magnesium showed strong positive correlations between the two methods, while calcium showed a weak negative correlation. The fertilizer contents estimated through the obtained regression lines and WDXRF quantification results indicated that 78 %–96 % of the sampling sites wherein all four elements that were detected were within an error of ±25 % of the measured values. Compared with the conventional diagonal soil sampling method for determining the concentration of fertilizer contents, through WDXRF analysis, distribution of the fertilizer contents was more quickly and efficiently determined and the planar resolution was improved.
