ARS | Publication request: Phosphorus Loss with Surface Irrigation

Submitted to: USDA NRCS Technical Notes
Publication Type: Government Publication
Publication Acceptance Date: October 10, 2004
Publication Date: May 10, 2005
Citation: Bjorneberg, D.L., Leytem, A.B. 2005. Phosphorus loss with surface irrigation. In: Walker, F., Russell, W., Dagnan, G., Dalton, A., editors. Phosphorus Best Management Practices: Protecting Water Quality. USDA-NRCS Fact Sheet. Available: http://www.sera17.ext.vt.edu/SERA_17_Publications.htm.

Interpretive Summary: Water flows by gravity over the soil during surface irrigation. Flowing water can detach, transport and deposit sediment and associated nutrients during irrigation. Total phosphorus transported during surface irrigation includes phosphorus attached to sediment and phosphorus dissolved in water. Most phosphorus is associated with sediment in runoff from row-crop fields where soil erosion occurs. On pasture or close-seeded crops like small grain or alfalfa, most of the phosphorus is dissolved in the flowing water. Phosphorus losses with surface irrigation can be reduced with management practices that limit phosphorus in the soil, reduce soil erosion on the field, and remove sediment before water flows from the field.

Technical Abstract: Water flows by gravity over the soil during surface irrigation. Flowing water can detach, transport and deposit sediment and associated nutrients during irrigation. Total phosphorus transported during surface irrigation includes phosphorus attached to sediment and phosphorus dissolved in water. Most phosphorus is associated with sediment in runoff from row-crop fields where soil erosion occurs. On pasture or close-seeded crops like small grain or alfalfa, most of the phosphorus is dissolved in the flowing water. Phosphorus losses with surface irrigation can be reduced with management practices that limit phosphorus in the soil, reduce soil erosion on the field, and remove sediment before water flows from the field.