|Rotz, Clarence - Al|
|Bjorneberg, David - Dave|
|HAGEVOORT, ROBERT - New Mexico State University|
|WILLAMSON, JEBEDIAH - New Mexico State University|
|Slaughter, Amalia - Amy|
Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/11/2022
Publication Date: N/A
Interpretive Summary: Manuresheds represent the cropland area needed to utilize a farm’s manure as a crop nutrient source without adverse environmental impacts. Off-farm transport of manure is often needed when manure nutrient production exceeds the farm’s crop nutrient assimilation capacity, but case studies from four diverse diary regions (Minnesota, Idaho, New Mexico, and Pennsylvania) showed that local geography, climate, and dairy structure and size present unique challenges for each region. Transportation costs often complicates off-farm utilization of manures. However, development of social network connecting dairies with crop farms needing nutrients, manure nutrient extraction methods, and more efficient nutrient management approaches are reducing nutrient excesses and facilitating manure transport when needed.
Technical Abstract: Manure management is a challenge to dairy farms across the United States, complicated by a diversity of production systems and constraints that vary at scales from farm to region. Dairy manuresheds range from those contained on-farm to those that must extend outside the farm-gate and therefore involve neighboring farms and their associated nutrient management requirements. We describe the challenges and opportunities to manureshed management across U.S. dairy farms through original analyses and investigation of local manureshed characteristics. In Minnesota, a growing proportion of Jersey cattle and differences in continuous corn (Zea mais) versus corn/alfafa (Medicago sativa) rotations both contribute to the extent of land that can absorb dairy manure nutrients. Farm-gate budgets reveal N-based manuresheds that can be contained within Idaho dairies, but P-based manuresheds were shown to extend beyond the farm-gate. In New Mexico, relocation of surplus manure nutrients off the farm is common practice via farmer-to-farmer social networks; incentives to formalize and strengthen these networks could ensure sustainable manureshed management as reduced groundwater availability constrains the assimilative capacity of on-farm forage cropping systems in this desert state. In New York and Pennsylvania, a preponderance of smaller operations and different state policies complicate manure export from dairy farms. Innovation in manure treatment systems is improving the potential for off-farm transport of dairy manures.