Phosphorus Problems
Phosphorus Problems and Solutions: Part 1 Ohio legislators are considering a number of rules and regulation regarding phosphorus (P) fertilizer and manure. The following article outlines some facts about P runoff. Weather is one of the biggest culprits in P runoff. Over the last several decades, precipitation has changed with more numerous precipitation events occurring with higher amounts, longer duration, and increased intensity. Due to weather, the key facts are that 90% of P runoff comes from 1-2 major runoff events each year and 80% of P runoff comes from 20% of the soil (Dr. Andrew Sharpley). Location and transport are key factors. Fields close to a creek, stream, or river contribute a considerable amount of P in surface runoff. Most soil P is stratified and P is located in the top 2- 3 inches of the topsoil and subject to soil erosion and surface runoff. On measuring P runoff, the P concentration (usually measured in parts per million) times the transport factor (vol...