Abstract In the European Alps traditional, low-input dairy farming systems still coexist with modern high-input intensive systems. This study aimed at evaluating the effect of different Alpine farming systems on the environmental footprint, production efficiency (gross energy conversion ratio, ECR) and competition between feed and food (potentially human-edible gross energy conversion ratio, HeECR). Data originated from 37 dairy farms located in the Trento province (eastern Italian Alps), from which four dairy systems were derived by performing non-hierarchical cluster analysis based on farm facilities and management features (traditional, either with tie or loose stalls, and intensive, either with or without use of silages, systems). Environmental footprint was computed using a cradle-to-farm gate Life Cycle Assessment model. One kg fat- and protein-corrected Milk (FPCM) and 1 m2 of agricultural land were used as functional units. Global warming (GWP), acidification (AP) and eutrophication (EP) potentials, cumulative energy demand (CED) and land occupation (LO) were included as impact categories. System boundaries included herd and manure management, on-farm feedstuffs production and purchased feedstuffs and materials. Mean impact values per 1 kg FPCM were 1.0 ± 0.3 kg CO2-eq (GWP), 21.1 ± 4.3 g SO2-eq. (AP), 6.3 ± 1.2 g PO4-eq. (EP), 5.0 ± 2.0 MJ (CED), 1.4 ± 0.5 m2/y (LO), whereas per 1 m2 were 0.8 ± 0.3 kg CO2-eq (GWP), 16.3 ± 4.2 g SO2-eq. (AP), 4.9 ± 1.3 g PO4-eq. (EP), 3.8 ± 1.8 MJ (CED). Mean ECR was 5.17 ± 0.89 MJ/MJ, with 88% of gross energy provided by non-human edible feedstuffs. A large variability was found both between and within dairy systems, in terms of environmental footprint and production efficiency. Impact values were slightly greater per unit of product and lower per unit of area in traditional than in intensive farms, although generally without significant differences. Production efficiency of traditional farms was 17% lower in terms of ECR but 59% greater in terms of HeECR, due to a lower proportion of purchased concentrates in animal rations, with a positive contribution to food balance and diet self-sufficiency. These results indicate that the transition from traditional towards intensive systems improved only slightly the environmental footprint of dairy farming, but increased markedly its dependence on external concentrate feeds and the feed-food competition. In perspective, different aspects of mountain dairy systems, such as the conversion into food of human non edible feeds, the low impacts at the local scale, the ability to conserve grasslands under a land-sharing perspective, and in general the associated ecosystem services, should be considered when aiming to improve their environmental sustainability.

中文翻译：

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不同山区奶牛养殖系统的环境影响和资源利用效率

摘要 在欧洲阿尔卑斯山，传统的低投入奶牛养殖系统仍然与现代高投入集约化系统共存。本研究旨在评估不同高山农业系统对环境足迹、生产效率（总能量转化率，ECR）和饲料与食物之间的竞争（潜在人类可食用总能量转化率，HeECR）的影响。数据来源于位于特伦托省（意大利东部阿尔卑斯山）的 37 个奶牛场，通过基于农场设施和管理特征（传统的，无论是平摊或松散摊位，以及密集的）进行非层次聚类分析，衍生出四个奶牛系统。 ，无论是否使用青贮饲料，系统）。使用从摇篮到农场大门生命周期评估模型计算环境足迹。一公斤脂肪和蛋白质校正牛奶 (FPCM) 和 1 平方米的农田被用作功能单元。全球变暖 (GWP)、酸化 (AP) 和富营养化 (EP) 潜力、累积能源需求 (CED) 和土地占用 (LO) 被列为影响类别。系统边界包括畜群和粪便管理、农场饲料生产以及采购的饲料和材料。每 1 kg FPCM 的平均影响值为 1.0 ± 0.3 kg CO2-eq (GWP)，21.1 ± 4.3 g SO2-eq。(AP)，6.3 ± 1.2 g PO4-eq。(EP)、5.0 ± 2.0 MJ (CED)、1.4 ± 0.5 m2/y (LO)，而每 1 m2 为 0.8 ± 0.3 kg CO2-eq (GWP)、16.3 ± 4.2 g SO2-eq。(AP)，4.9 ± 1.3 g PO4-eq。(EP), 3.8 ± 1.8 兆焦耳 (CED)。平均 ECR 为 5.17 ± 0.89 MJ/MJ，其中 88% 的总能量由非人类食用饲料提供。在乳制品系统之间和内部都发现了很大的可变性，在环境足迹和生产效率方面。与集约化农场相比，传统农场每单位产品的影响值略高，每单位面积的影响值略低，但通常没有显着差异。传统农场的生产效率在 ECR 方面低 17%，但在 HeECR 方面高 59%，这是由于动物口粮中购买的浓缩物比例较低，对食物平衡和饮食自给自足有积极贡献。这些结果表明，从传统系统向集约化系统的转变仅略微改善了奶牛养殖的环境足迹，但显着增加了其对外部精饲料和饲料食品竞争的依赖。从角度来看，山区乳品系统的不同方面，