Developed by Lakesh Sharma, University of Maine Cooperative Extension Assistant Professor of Sustainable Agriculture, and  Sukhwinder Bali, Assistant Professor of Sustainable Agriculture, University of Maine Cooperative Extension For information about UMaine Extension programs and resources, visit extension.umaine.edu.Find more of our publications and books at extension.umaine.edu/publications/. Why soil phosphorus (P) levels matter to Aroostook County potato