Selenium Accumulation by Brassica Napus Grown in Se-Laden Soil From Different Depths of Kesterson Reservoir

Selenium (Se) may be present in soils and sediments in high concentrations and yet not be mobile or available for plant uptake. Phytoremediation of Se by canola (Brassica napus) was evaluated in sediment from Kesterson Reservoir at three different depths (0 to 30, 30 to 60, 60 to 90?cm) under greenhouse and field conditions. In the greenhouse study, total soil Se concentrations at preplant ranged from 10 to 112?mg kg^?1. Shoot Se concentrations of canola were 182, 53, and 19?mg kg^?1 DM in the 0 to 30, 30 to 60, and 60 to 90?cm depths, respectively. Percentages of Se accumulated by canola relative to total Se loss in the soil at postharvest were as high as 24%. In the field study, total soil Se concentrations were as high as 26?mg kg^?1 soil. Field-grown canola accumulated approximately 50?mg kg^?1 DM, which accounted for less than 10% of total Se lost in the soil at postharvest. Phytoremediation of Se-laden soils under field conditions was about 50% of that observed under controlled greenhouse conditions. This relationship may be useful for prediction of field remediation operation using greenhouse generated data.