Nebraska fields listed as concentrated animal feeding operations (CAFOs) must have a Field Phosphorus Risk Assessment before manure can be applied after Jan. 1, 2007.

Confined livestock operations with a maximum one-time capacity of 2,500 swine weighing more than 55 lb. are automatically ranked large CAFOs, says Ken Lamb, Nebraska Department of Environmental Quality. Some operations with fewer animals may need a permit if there is a direct link between the livestock operation and surface water.

Two phosphorus indexes are approved for Nebraska. For more information about CAFOs or the phosphorus index, visit the University of Nebraska's Comprehensive Nutrient Management Planning Web site at