Biosolids Land Application and Phosphorus: A Simple Runoff Study.

Biosolids land application supplies plant nutrients necessary for crop production. Most land application programs are based on the premise of biosolids application to supply nitrogen, yet this may lead to phosphorus (P) over-application. As soil P concentration increases, so does the likelihood for P movement off-site and the potential to negatively impact adjacent water bodies. We collected intact coarse or fine textured soils from irrigated or dryland sites that had biosolids land application histories. In a simple rainfall simulation (purchased from Conservation Demonstrations; Salina, KS), we tested the ability of a 10 year – 24 hour rain event to affect total, dissolved, and biological P movement in runoff and leachate. Results will be discussed.