UCD School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
Animal & Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
J Environ Manage. 2018 Oct 1;223:625-632. doi: 10.1016/j.jenvman.2018.06.074. Epub 2018 Jun 30.
The environmental impact of dairy production in Ireland has been widely studied and it is known that regional differences in management and impact are driven by climate. Climate change projections for Ireland predict increasing temperature, change in rainfall patterns and decreasing in solar radiation, varying by agroclimatic region. This study evaluated the environmental impacts of low-cost, grass-based, rotational-grazing dairy production on poorly drained soils under climate change. The Dairy_sim model was used to determine the theoretical optimum dairy system management for five different locations in Ireland assuming a poorly drained soil resource under baseline (1981-2000) and future climate scenarios (2041-2060, high and low emissions scenarios). An optimum system was defined as having maximum grass production and grazed grass in the diet, minimum necessary silage, minimum imported feed, minimum housing days and a very small silage surplus. Life cycle assessment was then used to quantify the environmental impacts (climate change, eutrophication and acidification) for all scenarios. The dairy production systems were predicted to be more productive in the future, with climate change impacts per unit milk reduced or the same, acidification impacts reduced and eutrophication impacts reduced. The absolute emissions driving climate change and eutrophication were predicted to significantly increase for the future low emission scenario, and emissions driving acidification were predicted to slightly increase. The predictions indicate that system adaptation to mitigate absolute emissions are needed rather than just policies that focus on impacts per unit output.
爱尔兰乳制品生产的环境影响已经得到了广泛的研究，人们知道，管理和影响的区域差异是由气候驱动的。爱尔兰气候变化预测表明，气温升高、降雨模式变化和太阳辐射减少，这些变化因农业气候区而异。本研究评估了在气候变化下，低成本、基于草的、轮牧式乳制品生产对排水不良土壤的环境影响。Dairy_sim 模型用于确定在假设存在排水不良土壤资源的情况下，爱尔兰五个不同地点的理论最佳乳制品系统管理，假设在基准（1981-2000 年）和未来气候情景（2041-2060 年，高和低排放情景）下。最佳系统被定义为具有最大的草产量和放牧草在饮食中，最小必要的青贮饲料，最小的进口饲料，最小的住房天数和非常小的青贮饲料过剩。然后使用生命周期评估来量化所有情景的环境影响（气候变化、富营养化和酸化）。预计未来乳制品生产系统将更具生产力，每单位牛奶的气候变化影响减少或相同，酸化影响减少，富营养化影响减少。预计未来低排放情景下，驱动气候变化和富营养化的绝对排放量将显著增加，而驱动酸化的排放量预计将略有增加。这些预测表明，需要适应系统以减轻绝对排放量，而不仅仅是关注单位产出影响的政策。
