Abstract
The study was based on measuring the concentration of metals in the soil and in the surrounding grass varieties used in the area (Kikuyocloa clandestinum and Brachiara Brizantha) to determine their mobility, measured as a percentage of soil transfer to the grass. Sites from the northern region of Costa Rica were selected, divided into Chorotega Region and Huetar Norte Region. The concentrations of potassium (K), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) were identified and compared. It was experimented with the mobility of these elements from the soil to the grass foliage, due to its importance as nutrients in the fertility of soil and grasses. Mn, Fe, Cu and Zn are considered heavy metals and in the studied areas do not constitute contaminants. The energy dispersive X-ray fluorescence technique (FRXDE) was used to determine the elementary composition in the soil and grass foliage matrices, as it is a non-destructive technique and multiple and simultaneous elemental analysis. When comparing K concentrations, higher values were found in grass than in soil, so it was ruled out to calculate the mobility with the methodology defined in this work. For the remaining elements, mobility was calculated as the percentage of transfer of metals when moving from the ground to the grass. The results obtained showed a moderate average transfer for Ca (37.04%) and Zn (24.75%), and a low transfer for Mn (1.85%), Fe (1.35%) and Cu (4.35%).
Keywords: X-ray Fluorescence; heavy metals; soil; grass.