To reduce nutrient loading of the Chesapeake Bay, Maryland has passed a bill that limits nitrogen and eliminates phosphorus in most fertilizers. The act also establishes best practices for public fertilizer application and a training and licensing program for professionals. The law, which should be fully implemented by October 2013, is designed to target commercial lawn care providers and homeowners who contribute 14% of nitrogen and 8% of phosphorus loadings according to the Chesapeake Bay Commission. Check here for more information.