Impact of Land-Applied Arsenicals in Alabama.

Many agricultural industries in Alabama (e.g., poultry, cotton, and turfgrass management) use arsenicals to improve their commodity.  The organoarsenical roxarsone is used in the poultry industry to increase weight gain and control gut parasites in chickens.  The arsenic is largely excreted by the chickens and then land-applied as an unwanted constituent of nutrient-rich manure-fertilizer.  In the cotton and turf industries, monosodium methanearsonate (MSMA) and disodium methanearsonate (DSMA) are widely applied to control weeds.  There is currently no regulation for land-application of arsenicals from animal waste or herbicides and there are no studies that have investigated land-applied arsenic in Alabama soils.  Repeated application of arsenicals to soils without regard to their accumulation, mobility, or potential toxicity is risky.  Fate and toxicity of arsenic is highly dependent on its form (species), which depends on soil characteristics.  The objective of the proposed research is to determine the extent of arsenic accumulation from previously applied arsenicals in Alabama soils.  Sites with histories of applied arsenicals will be compared with adjacent sites without history of applied arsenicals for natural background arsenic levels. This research seeks to identify particular industries, soils, and/or conditions where land application of arsenic is potentially hazardous for future study.