Storing manure provides opportunities for dairy farms to maximize using the manure value as a fertilizer, reduce handling costs, and minimize its potential to pollute the environment. However, it also presents the potential to lose the nitrogen in manure to the atmosphere through volatilization as ammonia. Knowing the quantities of nitrogen lost is critical to inform the decision-making process related to developing mitigation strategies. This study aimed to quantify ammonia lost at the farm scale level from manure stored in a clay pit at a dairy farm during two storage periods. The ammonia concentrations, manure temperature, and local meteorological factors were measured and used to calculate the ammonia flux. Further, the crusting on stored manure surface was characterized and related to ammonia loss. The ammonia flux ranged from 0.26 ± 0.01 g m⁻² d⁻¹ to 1.30 ± 0.05 g m⁻² d⁻¹, averaging 0.57 ± 0.02 g m⁻² d⁻¹. Of the local meteorological factors, the wind speed influenced ammonia loss the most, but the ammonia flux patterns were related more closely to the manure temperature than other meteorological factors. The crusting of the manure suppressed the ammonia loss. However, manure agitation before land application accounted for about 25% of the nitrogen loss. The ammonia lost during storage accounted for about 5% of the total nitrogen in the manure going into storage. The outcome of this work contributes knowledge that farmers, practitioners, and policymakers can use to design and improve the guidelines to formulate effective farm manure management and mitigation practices and regulatory programs to minimize ammonia loss from dairy farms using manure scrapers and clay storage pits as part of their manure management system.

储存粪便为奶牛场提供了机会，最大限度地利用粪便作为肥料的价值，降低处理成本，并最大限度地减少其污染环境的可能性。然而，它也有可能通过氨的挥发将粪便中的氮损失到大气中。了解氮损失量对于为制定缓解策略相关的决策过程提供信息至关重要。本研究旨在量化两个储存期间储存在奶牛场粘土坑中的粪便在农场规模损失的氨。测量氨浓度、粪便温度和当地气象因素并用于计算氨通量。此外，储存粪便表面结痂的特征与氨损失有关。氨通量范围为 0.26 ± 0.01 g m^-2 d ^-1至 1.30 ± 0.05 g m ^-2 d ^-1，平均为 0.57 ± 0.02 g m ^-2 d ^-1 。在当地的气象因素中，风速对氨损失的影响最大，但氨通量模式与粪便温度的关系比其他气象因素更密切。粪便的结壳抑制了氨的损失。然而，施肥前的粪便搅拌约占氮损失的 25%。储存期间损失的氨约占进入储存的粪便中总氮的5%。这项工作的成果贡献了农民、从业者和政策制定者可以用来设计和改进指南以制定有效农场的知识粪便管理和缓解措施以及监管计划，以最大限度地减少奶牛场使用粪便刮板和粘土储存坑作为其粪便管理系统一部分的氨损失。