Winter Hay Feeding Sites and Effects On Pasture Attributes.

Dedicated hay-feeding areas are needed in most forage-livestock production systems. The high number animals per unit of area in hay feeding areas  may promote changes on some soil and sward attributes. Livestock presence can affect soil fertility, soil compaction and microbial activity. Furthermore, hay-feeding areas may become overgrazed and become  focal points for weed invasion.  In 2008, a study was initiated at the Virginia Tech Shenandoah Valley AREC at Steeles Tavern, VA to evaluate the impact of winter hay feeding areas on pasture attributes. In this study, we evaluated 24, 1 ha pastures within a rotationally stocked grazing system.  One half (12 pastures) were stocked with 7 or 8 beef cows and fed hay from January to April.  The other control pastures (12) were rotationally grazed during the growing season and had no hay feeding area.  We measured botanical composition, herbage mass, soil fertility indices, soil compaction and soil respiration in paired pastures during 2009 and 2010. Tall fescue and bluegrass were the main species found on pastures.  During a dry summer (2008) there was more bluegrass and less clover than 2009, when rainfall was higher.  Overall species composition was similar between paired pastures.  Pastures with hay feeding accumulated significantly more forage (340 g m^-2) than control pastures (226 g m^-2) in 2009.  Soil P and K concentrations were higher in hay feeding pastures likely due to greater nutrient import.   In 2009 and 2010, soil penetration resistance (PR) was higher in hay feeding pastures, but PR values were less than 2500 KPa, which is considered the threshold where compaction can adversely impact plant growth.  Soil respiration showed seasonal variation but no difference between hay feeding and rotational pastures. Our initial data suggests that winter hay feeding had few negative effects on pasture attributes.  Nonetheless, the high concentration of manure in these areas could contribute to environmental problems (e.g., nutrient runoff) in some cases.  Spreading out winter hay feeding across farm would be a better strategy to minimize potential environmental problems and take better advanatage of the nutrients imported from hay feeding.