Nitrogen (N) is the most limiting nutrient for productive agriculture. The principal N inputs on dairy farms are feeds, manure, fertilizers, biologically-fixed N, soil N and atmospheric N deposition. The relative importance of each N source to the production of crops, pasture and milk depends on several factors, including a farm’s stocking rate (animals per unit land area), which influences the type and amount of feed grown on a farm, feed and fertilizer purchases, manure management, N use efficiency, whole-farm N balances and environmental N loss. Soil type also impacts N use efficiency (NUE, the amount of applied N transformed into products) and N loss as ammonia (NH3), nitrate (NO3-) and nitrous oxide (N2O). This presentation will demonstrate how stocking rate, fertilizer, feed and manure management impact NUE and N loss from dairy production systems.
Soil Science Extension
University of Wisconsin Madison