Comparative Analysis and Evaluation of Handheld X-ray Fluorescence Spectrometry to Measure Silicon in Crop Plants

Rice, wheat and corn are the three most consumed crop foods worldwide and, as such, are important when considering future global food security. All three species are members of the Poaceae family and are silica accumulators. For those plants that accumulate silica, silica fertilisation is considered to improve plant health and alleviate abiotic and biotic stresses thereby lessening reliance on pesticides. Measuring the silicon (Si) content in soils and plants is useful for identifying Si-poor systems; however, traditional chemical digestion methods to measure Si are hazardous and time consuming. Advances in the sensitivity of handheld X-ray fluorescence spectrometers (hh-xrf) create new opportunities for rapid plant elemental analyses. We present a Si analysis of using two handheld X-ray fluorescence devices (SciAps X-300 and the Niton XL3t GOLDD+) compared with a traditional NaOH-digestion method. The SciAps was found to be more accurate than the Niton and the average time taken to analyse Si using the SciAps was four seconds per sample. These data support the use of hh-xrf for rapid analysis of Si and indicate there are additional opportunities for future research to accurately quantify potassium and phosphorus using this technology.