Phosphorus and Nitrogen in Rainfall Simulation Runoff after Fresh and Composted Beef Cattle Manure Application

Fresh beef cattle (Bos taurus) manure has traditionally been applied to cropland in southern Alberta, but there has been an increase in application of composted manure to cropland in this region. However, the quality of runoff under fresh manure (FM) versus composted manure (CM) has not been investigated. Our objective was to compare runoff quality under increasing rates (0, 13, 42, 83 Mg ha-1 dry wt.) of FM and CM applied for two consecutive years to a clay loam soil cropped to irrigated barley (Hordeum vulgare L.). We determined total phosphorus (TP), particulate phosphorus (PP), dissolved reactive phosphorus (DRP), total nitrogen (TN), NH4-N, and NO3-N concentrations and loads in runoff after one (1999) and two (2000) applications of FM and CM. We found significantly (P