Germination of Bouteloua dactyloides and Cynodon dactylon in a Multi-Polluted Soil

Mining wastes generate high environmental impacts, and population exposure to metals and metalloids. Phytoremediation is a technology that uses plants to remediate polluted sites, but one of its limitations is seed germination in soil with a high content of metals and metalloids. Bouteloua dactyloides (former Buchloe dactyloides ) is a native species from semiarid regions, while Cynodon dactylon is an invasive species; both are tolerant to harsh soil conditions. The objective of this research was to evaluate the germination of both species, exposed to a multi-polluted soil with As, Cd, Pb, and Zn of a mining site, considering different pH conditions (from 5.0 to 9.0). The study considered four repetitions by type of seed and soil pH. The highest germination of B. dactyloides was 83% at pH 7.8, while the greatest germination of C. dactylon was 34% at pH 6.0. These percentages are similar to those obtained in a standard germination test, which are 82.5% for B. dactyloides and 35% for C. dactylon . Germination was not reached in either species with soil at pH 5, owing to the fact that metals are more bioavailable in acid environments. B. dactyloides and C. dactylon had a high potential to germinate in multi-polluted soil at neutral pH, but further experiments are needed.