A Rapid and Nondestructive Plant Nutrient Analysis using Portable X-Ray Fluorescence

Portable X-ray fluorescence (PXRF) can provide a rapid and nondestructive analysis for environmentally important elements in plant matrices. No previous publication has been able to demonstrate the application of PXRF element determination in plant material. To assess the applicability of PXRF for total element analysis, four plant species of agricultural importance {corn (maize) ['Zea mays' L.], cotton ['Gossypium hirsutum' L.], soybean ['Glycine max' (L.) Merr.], and wheat ['Triticum aestivum' L.]} were collected across northern New South Wales (NSW), Australia. The effect of scanning time and particle size on data quality was also evaluated. For three plant species (corn, cotton, and soybean) there were significant linear relationships between the acid digest values and the PXRF readings for Ca, Co, Cr, Fe, K, Mn, Ni, P, S, Si, and Zn. Only slight reductions in the regression coefficient (r²) for Fe and Zn were observed in cotton when scanning time was reduced by more than half. Similar regressions between corn and cotton at 120 s demonstrated the potential for a single algorithm for plant matrices. The use of novel techniques to optimize PXRF settings for quantitative determination of total plant elements provides an efficient alternative to traditional plant digestion.