Rapid nutrient cycling improves forage quality and livestock productivity in pastures. Interseeding legumes may be a strategy to enhance N cycling, but effects of dung excreted from cattle grazing pastures with legumes on dung decomposition rates and soil N cycling have not been studied. Our objective was to evaluate how dung excreted from cattle grazing legume-interseeded, N-fertilized, and unfertilized smooth bromegrass (Bromus inermis Leyss.) pastures affects dung chemical composition, dry matter decomposition, CO2 flux, and N availability in soil. Freshly deposited dung was collected by hand from the legume-interseeded, N-fertilized, and unfertilized treatments, refrigerated, separately homogenized, and placed as pats in a neighboring unfertilized pasture. Each treatment was collected 3, 7, and 30 days after placing the pats in two experimental periods (June and August) in 2014. CO2 flux from dung was measured for each treatment, as well as a non-dung influenced control. Dung collections coincided with vegetation and diet samples from ruminally-fistulated cattle to examine effects of the pasture treatments on N cycling through the plant-animal-dung-soil complex. CO2 flux did not differ among treatments in June but tended to be greater from dung excreted in legume-interseeded pastures in August. Forage quality in all diets was high and comparable in June, but was relatively higher in legume-interseeded pastures in August.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.