Grinding Methods Influence Nutrient Analysis of Bahiagrass and St. Augustinegrass

Particle reduction is a necessary step during turfgrass tissue analysis and may result in contamination of the sample with one or more elements. Metals such as W or Zr may reduce contamination because the metals are void of any plant essential elements. The objective of this study was to determine the nutrient content of turfgrass tissue submitted to eight grinding methods. Leaf tissue from bahiagrass (Paspalum notatum Flugge) and 'Floratam' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] was collected and ground using one of the following eight methods: unground, Wiley mill, Cyclone mill, alumina beads, ceramic beads, stainless steel beads, tungsten carbide beads, and zirconium oxide beads. Tissue was analyzed for N, P, K, Ca, Mg, S, Al, Cu, Fe, Mn, Na, and Zn. Each method influenced turfgrass nutrient analysis by increasing, and in some cases decreasing, the concentration of one or more elements compared with unground tissue. Alumina and ceramic beads resulted in a decreased concentration of most elements, whereas the Wiley mill and tungsten beads resulted in an increase in N and Cu, and N and Mn, respectively. Grinding methods did not influence the concentration of P, K, S, Mn, or Na in bahiagrass but did alter their concentration in St. Augustinegrass. To minimize inaccurate analysis, the grinding method must account for additions or subtractions of elements resulting from the turfgrass species and the element analyzed.