Wednesday, November 7, 2007 - 12:30 PM
326-9

Effects of Bullet Removal and Vegetation on Pb Weathering and Leaching in Berm Soils of Florida Shooting Ranges.

Abioye Fayiga, Uttam Saha, and Lena Q. Ma. University of Florida, Univ. of Florida, Soil & Water Sci. Dept., Gainesville, FL 32611

The effects of bullets removal and vegetation on the weathering of bullets and leaching of lead in three berm soils of Florida shooting ranges were investigated in a greenhouse experiment. Bullets were removed by physical sieving. St Augustine grasses were grown in both sieved and unsieved soils for two months. In addition a no-vegetation control was included. Leaching was done five times and leachates analyzed for Pb, DOC and pH. At the end of the experiment, soil samples were analyzed for total, water-soluble and Mehlich 3- Pb, while plant samples were analyzed for plant biomass and Pb concentrations. Leachable Pb in unvegetated soils were significantly (P<0.05) higher than those from vegetated soils in range 3. The presence of grasses in this range soil reduced accumulative leachable Pb in sieved-soils by 63% and in the unsieved by 69% compared to the unvegetated soils. The unsieved soils had higher pH than the sieved soils except in range 1. The weathering of bullets in soils is responsible for the higher pH of unsieved soil/leachates. There was a significant correlation between the rhizosphere pH and the shoot lead concentration (P<0.05) implying root exudates may play a part in lead translocation and uptake in the grass.