Influence of Soil Pore Length upon Portable X-ray Fluorescence Spectrometer Measurements of Elements in Soils

摘要

To approximate the measurement accuracy of laborious lab approaches, soil inventories using field portable XRF (pXRF) spectrometers should take distorting parameters into account. Besides soil moisture, the length of water-filled soil pores may also affect X-ray intensity. Following the Arya-Paris approach of soil pore bundles, soil pore lengths were calculated for 20 riparian soil samples based on effective pore diameters obtained at specified pressure heads of the water retention curve. When contrasted against pXRF signals of lead, zirconium, and potassium, soil pore length information showed an explanation comparable to soil moisture values. Presumably, the bases and walls of soil pores are successively exposed to the excitation source during dewatering. Though its laborious determination, soil pore length calculation is based on comparatively static parameters, which may circumvent adverse effects occurring at moisture determination at steel-ring samples, such as artificial macropores in the course of sampling and transport or shrinkage of porosity due to pressure application.