USDA-ARS, Pasture Systems and Watershed Management Research Unit, University Park, Pennsylvania, USA.
Department of Plant Science, The Pennsylvania State University, University Park, Pennsylvania, USA.
J Environ Qual. 2024 Nov-Dec;53(6):823-831. doi: 10.1002/jeq2.20606. Epub 2024 Jul 31.
Dairy production is a key agricultural enterprise in the Upper Chesapeake Bay (UCB) basin, where phosphorous (P) and nitrogen (N) loading contribute to eutrophication. Import of forages and grains and application of mineral fertilizers contribute to nutrient imbalances in the basin. The UCB Long-Term Agroecosystem Research Cropland Common Experiment aims to evaluate diverse crop rotations that minimize the need for imported feed, maximize year-round living cover, and reduce nutrient losses. UCB's plot-scale experiment was established in 2018, incorporating an ongoing cropping system study that was established by the Pennsylvania State University in 2010. An alternative dairy cropping rotation (including silage and grain corn [Zea mayes L.], alfalfa [Medicago sativa L.]/orchardgrass [Dactylis glomerata L.] mix, winter rye silage [Secale cereale L.], and sorghum-sudangrass [Sorghum × drummondii (Steud.) Millsp. & Chas]) that employed manure injection, integrated pest management, and less frequent manure application was compared to a prevailing, conventionally managed silage corn-alfalfa rotation with higher manure application rates. A field-scale experiment was established in 2019 to monitor alternative production practices (manure injection and avoidance of neonicotinoid seed treatment) and prevailing practices in three fields on a commercial dairy farm. Findings suggest that crop rotation diversification, manure injection, and integrated pest management have the potential to increase the economic and environmental sustainability of dairy cropping systems, but long-term evaluation is needed for confirmation.
奶制品生产是切萨皮克湾上游流域（UCB）的主要农业产业，该流域的磷（P）和氮（N）负荷导致了富营养化。饲料和谷物的进口以及矿物肥料的施用导致了流域内养分失衡。UCB 长期农业生态系统研究农田通用实验旨在评估各种作物轮作，以最大限度地减少对进口饲料的需求，最大限度地保持全年的生物覆盖，并减少养分流失。UCB 的田间尺度实验于 2018 年建立，结合了宾夕法尼亚州立大学于 2010 年建立的正在进行的作物系统研究。一个替代的奶牛种植轮作（包括青贮玉米和谷物玉米[Zea mayes L.]、紫花苜蓿/果园草[Dactylis glomerata L.]混合青贮、冬黑麦青贮[Secale cereale L.]和高粱-苏丹草[Sorghum × drummondii (Steud.) Millsp. & Chas]）采用了粪肥注射、病虫害综合管理和较少频率的粪肥施用，与传统管理的青贮玉米-紫花苜蓿轮作进行了比较，后者粪肥施用量较高。2019 年建立了一个田间尺度实验，以监测替代生产实践（粪肥注射和避免使用新烟碱类种子处理）和商业奶牛场三个田块的流行实践。研究结果表明，作物轮作多样化、粪肥注射和病虫害综合管理有可能提高奶牛种植系统的经济和环境可持续性，但需要长期评估来确认。
