|GOOD, LAURA - University Of Wisconsin|
|PANUSKA, JOHN - University Of Wisconsin|
|BUSCH, DENNIS - University Of Wisconsin|
|LARSON, REBECCA - University Of Wisconsin|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/31/2015
Publication Date: 1/11/2016
Citation: Vadas, P.A., Good, L.W., Panuska, J.C., Busch, D.L., Larson, R.A. 2016. A new tool for estimating phosphorus loss from cattle barnyards and outdoor lots. Meeting Proceedings. Madison, WI.
Interpretive Summary: Phosphorus loss from agriculture is a water quality issue. On cattle farms, barnyards and feedlots can be significant sources of phosphorus loss, and there is a need to estimate that loss. We developed a user-friendly model that predicts annual runoff, erosion, and phosphorus loss from barnyards and feedlots. The model requires input for only annual precipitation and lot characteristics, including surface type (paved or earthen), cattle number and type, and how often a lot is cleaned. Testing showed the model reliably predicts annual runoff, sediment loss, and phosphorus loss from barnyards and feedlots. The new model can be used to develop whole-farm estimates of phosphorus loss and effectively target phosphorus loss mitigation practices.
Technical Abstract: Phosphorus (P) loss from agriculture can compromise quality of receiving water bodies. For cattle farms, P can be lost from cropland, pastures, and outdoor animal lots. We developed a new model that predicts annual runoff, total solids loss, and total and dissolved P loss from cattle lots. The model requires input for annual precipitation, lot surface type, soil test P for earthen lots, cattle number and type, frequency of cleaning, and % vegetative cover. The model estimates annual runoff using a precipitation dataset and Curve Number; annual solids loss based on annual runoff; annual particulate P loss based on solids loss and manure and soil P content; and annual dissolved P loss for each runoff event. Testing showed the model reliably estimated runoff, solids loss, and P loss from a wide variety of lots, and was more accurate than other, currently used models. The new lot model provides a valuable tool for developing whole-farm estimates of P loss and more effectively targets P loss mitigation practices.