Improving nitrogen (N) use on dairy farms provides both economic and environmental benefits. The goal is to have more N recycled on the farm (from crops to cows to manure used as fertilizer), which results in fewer N inputs purchased and brought onto the farm and less N lost to the environment. But because N cycles through the whole farm system, positive changes in one part of the N cycle might create negative tradeoffs in another part of the N cycle. Two emerging dairy industry trends are used to elaborate the complexity of N use and N loss from dairy production systems (1) feeding less protein to reduce both feed costs and emissions of ammonia and nitrous oxide (the most potent agricultural greenhouse gas) from the farm, and (2) feeding more corns silage and less alfalfa silage to feed more cows and reduce feed costs.
Soil Science Extension
University of Wisconsin Madison