Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: May 15, 2005
Publication Date: July 17, 2005
Citation: Sedorovich, D., Rotz, C.A., Vadas, P.A. 2005. Predicting management effects on phosphorus loss from farming systems. American Society of Agricultural Engineers Meetings Papers. Paper No. 053053. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: A process-level soil phosphorus (P) model including surface and subsurface components was developed to predict soluble, sediment-bound, and total P losses from fields within a farm. Preliminary verification indicated that the model accurately predicted soluble P losses but under-predicted total P losses. By incorporating this model into the Integrated Farm System Model (IFSM), average annual P losses for several farm management systems were simulated. Analyzing alternative practices in the context of the whole-farm allowed the impacts on other aspects of a farm, such as nitrogen losses and profitability, to be evaluated along with P losses and the whole-farm balance of P. Simulations with IFSM analyzed the effects of manure handling and tillage systems on P losses from dairy farms. Manure handling strategies that used six-month storage and field application by injection decreased total P loss by 30% compared to daily surface application, but the increased production costs reduced annual farm net return by about $30/cow. Compared to moldboard plow tillage systems, use of conservation tillage and no-till systems reduced total P loss by 45% and 59%, respectively, with little effect on farm profitability. Reduced tillage increased soluble P loss, suggesting that conservation tillage and no-till systems should be combined with systems using manure injection to reduce all forms of P loss.