Forage Production and Nutrient Removal by Smooth Bromegrass On a Vegetated Treatment Area.

Beef cattle feedlots pose serious environmental challenges associated with nutrient runoff. Smooth bromegrass is a perennial rhizomatous grass that is widely used in USA and Canada for forage production. The objective of this research is to determine the best management system for producing forage from a bromegrass VTA while maintaining the capacity of the VTA to remove nutrients from feedlot effluent. Four harvest management treatments (1-, 2-, and 3-harvest per year and an un-harvested control) were applied during spring 2005 and evaluated over a 5-yr period in a smooth bromegrass sward on a VTA near Howard, SD. Forage production ranged from 6.2 to 9.9 Mg ha^-1in 2005 and from 6.0 to 7.2 Mg ha^-1 to 8.5 Mg ha^-1 in 2007 for 1- and 3-harvest systems, respectively. Nutrient removal by the bromegrass was 83 kg ha^-1 N and 8 kg ha^-1 P for the 1-harvest treatment in 2006 to and 311 kg ha^-1 N and 32 kg ha^-1 P for the 3-harvest treatment in 2007. These results indicated that high amounts of forage could be produced from this VTA and that smooth bromegrass was an effective procurer of N and P.