Northeast Research and Demonstration Farm
Manure or fertilizer can be used to supply the phosphorus (P) needs of crops. However, excess P application increases the risk of P loss from fields and of water quality impairment through increased algae growth. Poor water quality in many Iowa lakes has prompted questions about the impact of P management practices on P loss from fields and the effectiveness of using agronomic soil tests for environmental purposes.
Iowa State University
Mallarino, Antonio P.; Sawyer, John E.; Klatt, Jeremy; Kanwar, Rameshwar S.; Pederson, Carl H.; Baker, James L.; and Pecinovsky, Kenneth T., "Fertilizer and Swine Manure Management Systems: Impacts on Agronomic and Environmental Soil Phosphorus Tests and on Phosphorus Loss with Subsurface Drainage" (2003). Iowa State Research Farm Progress Reports. 1498.