Sustainablesuccess of the Northern High Plains (NHP) crop and livestock industry is limited by market accessibility, infertile soils, short growing seasons, and availability of high nutritive value, low-cost feed. Adoption of the tropical legume, Crotalaria juncea L. (commonly known as sunn hemp), into NHP cropping systems could improve the sustainability of the rotation by fitting into summer growing windows and being used as a hay alternative. Rainfed and irrigated studies were conducted in Lingle, WY, to determine the target planting date for sunn hemp in the NHP. Later planting day of year was correlated with increased percent establishment in the rainfed study but had no effect in the irrigated study. In both irrigated and rainfed studies, planting between 8 June and 18 June maximized biomass accumulation. Biomass accumulation 60 d after planting ranged from 0.2 to 5.1 Mg ha^–1 in the rainfed study and 1.2 to 4.2 Mg ha^–1 in the irrigated study. For both irrigated and rainfed studies, the nutritive value of sunn hemp was high with crude protein greater than 220 g Kg^–1, acid detergent fiber less than 305 g Kg^–1, neutral detergent fiber less than 331 g Kg^–1, relative feed values above 183, and total digestible nutrients greater than 590 g Kg^–1. Planting date did not affect nutritive value. Sunn hemp grown in the NHP has a 60-d yield potential 5.1 Mg ha^–1, should be planted between 8–18 June to 60-d biomass production, and has nutritive value equivalent to supreme quality alfalfa (Medicago sativa L.) hay.

中文翻译：

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Sunn 大麻种植日期对怀俄明州东南部生长、生物量积累和营养价值的影响

北部高平原 (NHP) 作物和畜牧业的可持续成功受到市场准入、土壤贫瘠、生长季节短以及高营养价值、低成本饲料的可用性的限制。采用热带豆科植物Crotalaria junceaL.（通常称为 sunn 大麻），进入 NHP 种植系统可以通过适应夏季生长窗口并用作干草替代品来提高轮作的可持续性。雨养和灌溉研究在怀俄明州灵乐进行，以确定 NHP 中晒麻的目标种植日期。在雨养研究中，一年中较晚的种植日与增加的建立百分比相关，但在灌溉研究中没有影响。在灌溉和雨育研究中，6 月 8 日至 18 日之间的种植使生物量积累最大化。在雨育研究中，种植后 60 天的生物量积累范围为 0.2 至 5.1 Mg ha ^–1和 1.2 至 4.2 Mg ha ^–1在灌溉研究中。对于灌溉和雨育研究，晒麻的营养价值很高，粗蛋白大于 220 g Kg ^–1，酸性洗涤纤维小于 305 g Kg ^–1，中性洗涤纤维小于 331 g Kg ^–1，相对饲料值高于 183，总可消化营养素大于 590 g Kg ^–1。种植日期不影响营养价值。在 NHP 中种植的 Sunn 大麻具有 5.1 Mg ha ^–1的 60 天产量潜力，应在 6 月 8-18 日至 60 天生物量生产之间种植，其营养价值相当于优质苜蓿 ( Medicago sativa  L.) 干草.