In agricultural regions, like Whatcom County, Washington, crop and dairy production co-exist, but increased agricultural specialization and intensification have divorced what was, historically, an integrated approach to production. This agricultural segregation contributes to farm, regional and watershed-scale nutrient imbalances, and several different management approaches have been devised to improve, correct and close these nutrient cycling disparities. In high-density production regions, utilizing locally produced bio-based fertilizers may provide one avenue toward closing regional nutrient loops. Technologies such as dairy-operated nutrient recovery systems may help improve the flow of nutrients between dairy and cropping systems by extracting nutrients from raw manure and producing materials that are more easily used on farms than raw manure. To evaluate the potential impact of a nutrient recovery system and its related product, we estimated nitrogen balances between cropland use and manure production within Whatcom County, Washington and examined a theoretical scenario in which a specific nutrient recovery product was utilized across the region. We considered one economic barrier, transportation cost, and calculated a hypothetical comparison for transporting nitrogen in two forms, a downstream nutrient recovery product and raw manure. The scenarios presented here demonstrate a potential gap between regional nutrient supply and demand, illustrate the tradeoffs with a technological approach, and make clear that both technological tools and practical management strategies are needed to address the challenges of redistributing nutrients in high-density production areas.

中文翻译：

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估算和比较农田氮需求与奶牛场养分回收：华盛顿州 Whatcom 县的案例研究

在华盛顿州沃特科姆县等农业地区，农作物和奶制品生产并存，但农业专业化和集约化程度的提高与历史上的综合生产方式脱节。这种农业隔离导致农场、区域和流域规模的养分失衡，并且已经设计了几种不同的管理方法来改善、纠正和缩小这些养分循环差异。在高密度生产地区，利用当地生产的生物基肥料可能为关闭区域养分循环提供了一种途径。奶牛场养分回收系统等技术可能有助于改善奶牛场和种植系统之间的养分流动，方法是从生粪中提取养分并生产比生粪更容易在农场使用的材料。为了评估养分回收系统及其相关产品的潜在影响，我们估计了华盛顿州 Whatcom 县农田利用和粪便生产之间的氮平衡，并研究了在该地区使用特定养分回收产品的理论情景。我们考虑了一个经济障碍，即运输成本，并计算了以两种形式运输氮的假设比较，即下游养分回收产品和生粪肥。这里提出的情景展示了区域养分供需之间的潜在差距，说明了技术方法的权衡，并明确指出需要技术工具和实用的管理策略来解决高密度生产区重新分配养分的挑战。