The Eucha/Spavinaw phosphorus index: A court mandated index for litter management

Phosphorus (P)-based management strategies have been adopted in state planning standards nationwide, as most states have modified and adapted the original P index approach to better assess local landscape characteristics and management practices. However, P-based management strategies and environmental issues have become the focus of legal action within and between the states of Arkansas and Oklahoma due to differing management strategies in trans-boundary watersheds. A court settlement agreement was reached between parties in July 2003 requiring the development of a new P index by January 1, 2004 for use in writing nutrient management plans throughout the entire Eucha/Spavinaw watershed. The University of Arkansas found it most appropriate to modify the existing P index already in use in Arkansas to meet terms of the settlement agreement and to better reflect landscape characteristics and management practices specific to the Eucha/Spavinaw watershed. Hence, the Eucha/Spavinaw P index was developed and submitted to the court. By court decree, nutrient management plans in the watershed were written using the Eucha/Spavinaw P index beginning in February 2004. The Court issued further modifications to the Eucha/Spavinaw P index prior to release because the court felt that the specific P index did not fully comply with the settlement agreement. Through 2004, it was reported that the implementation of the Eucha/Spavinaw P index resulted in recommended litter application rates that were approximately one-third the rates that were common before the implementation of the Eucha/Spavinaw P index. Litter application rates recommended by the Eucha/Spavinaw P index were as much as 60 percent lower than application rates that would be recommended with the Arkansas phosphorus index for pastures as currently used.