Agriculture is a key contributor to environmental degradation and to global change. Consequently, the design of sustainable agricultural systems and the assessment of their relevance is a major priority for European agriculture. Different cropping systems, with variable objectives and constraints, can be used in cereal production in Spain. This study focused in comparing three winter barley cropping systems, ranging from intensive no-till to organic approaches. To assess the environmental impacts of each system, a Life Cycle Assessment was conducted. The findings indicate that the impacts varied depending on the chosen functional unit. When land area was considered the functional unit, the lowest impacts were obtained in the organic system, while the no-till system showed the highest. This difference was primarily attributed to variations in N fertilization. Nitrogen use had a significant impact across various categories, primarily due to the energy demands for its production and transportation, as well as the emissions of NH3 and N2O. However, when evaluating agricultural goods production as the functional unit, the organic system exhibited the highest impacts in terms of energy demand, freshwater ecotoxicity and freshwater eutrophication. These differences are explained by the loss of production in the fallow year and the low yields of the legume crop. The middle-way option provided the lowest impacts when economic net revenues were considered. The main reason for this was its higher total revenues associated to high crop production and EU subsidies.

中文翻译：

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地中海条件下三种不同种植系统对大麦生产的环境影响比较


农业是环境退化和全球变化的关键因素。因此，可持续农业系统的设计和相关性评估是欧洲农业的重中之重。在西班牙，不同的种植系统，具有不同的目标和限制，可用于谷物生产。本研究的重点是比较三种冬季大麦种植系统，从密集免耕到有机方法。为了评估每个系统对环境的影响，我们进行了生命周期评估。研究结果表明，影响因所选的功能单元而异。当土地面积被视为功能单位时，有机系统的影响最小，而免耕系统的影响最高。这种差异主要归因于氮肥的变化。氮的使用对各种类别都有重大影响，主要是由于其生产和运输的能源需求，以及 NH3 和 N2O 的排放。然而，当评估农产品生产作为功能单位时，有机系统在能源需求、淡水生态毒性和淡水富营养化方面表现出最大的影响。这些差异可以用休耕年的产量损失和豆类作物的低产量来解释。当考虑经济净收入时，中间方案提供的影响最小。造成这种情况的主要原因是它与高农作物产量和欧盟补贴相关的更高总收入。