New Tool for Cleaning Up Soils and Waterways: Prickly Pear

Selenium at high concentrations can affect plants, fish and migratory birds. Land areas which were covered with water in ancient times have large deposits of selenium which is carried to other habitats during rainfall. USDA's soil scientist Gary Banuelos discovered that planting prickly pear cactus (Opuntia ficus-indica) could solve the problem. Bañuelos studied five prickly pear varieties from Mexico, Brazil and Chile for salt and boron tolerance in selenium-laden soils, and analyzed the soils and sediments in the field test plots.

Results published in the journal Soil Use and Management shows that prickly pear grew well in the poor quality soils with very little water and the plants took up selenium. Selenium was volatilized by the plant and some concentrations were found in the fruits and leaf-like stems. A cactus variety from Chile performed best in the trial plots, showing highest tolerance to salt and boron in the selenium-laden soils, as well as being the best at producing fruit and accumulating and volatilizing selenium. The work is continuing with a focus on selecting specific varieties that can be used as bioremediation tools.

View the news release at http://www.ars.usda.gov/is/pr/2012/120118.htm