ABSTRACT

In this study, Life Cycle Assessment (LCA) methodology was combined with the agro-ecosystem model DNDC to assess the climate and eutrophication impacts of perennial grass cultivation at five different sites in Sweden. The system was evaluated for two fertilisation rates, 140 and 200 kg N ha⁻¹. The climate impact showed large variation between the investigated sites. The largest contribution to the climate impact was through soil N₂O emissions and emissions associated with mineral fertiliser manufacturing. The highest climate impact was predicted for the site with the highest clay and initial organic carbon content, while lower impacts were predicted for the sandy loam soils, due to low N₂O emissions, and for the silty clay loam, due to high carbon sequestration rate. The highest eutrophication potential was estimated for the sandy loam soils, while the sites with finer soil texture had lower eutrophication potential. According to the results, soil properties and weather conditions were more important than fertilisation rate for the climate impact of the system assessed. It was concluded that agro-ecosystem models can add a spatial and temporal dimension to environmental impact assessment in agricultural LCA studies. The results could be used to assist policymakers in optimising use of agricultural land.

摘要

在这项研究中，将生命周期评估（LCA）方法与农业生态系统模型DNDC相结合，以评估瑞典五个不同地点的多年生草种植对气候和富营养化的影响。评价该系统的两个施肥速率，分别为140和200 kg N ha ^-1。气候影响显示调查地点之间存在很大差异。对气候影响的最大贡献是土壤N ₂ O排放以及与矿物肥料制造相关的排放。预计最高的气候影响发生在粘土和初始有机碳含量最高的地方，而沙质壤土由于N ₂含量较低而受到的影响较小。由于高的碳固存率，O排放和粉质粘土壤土。沙质壤土的富营养化潜力最高，而质地较细的土壤富营养化潜力较低。根据结果​​，对于所评估系统的气候影响，土壤特性和天气条件比施肥速率更为重要。结论是，农业生态系统模型可以为农业LCA研究中的环境影响评估增加时空维度。该结果可用于帮助决策者优化农业用地。