ABSTRACT Climate change tends to intensify extreme weather events worldwide, negatively affecting agriculture and threatening global food security. More resilient agroecosystems are required to assure yield stability. In this research, which was carried out in a Mediterranean environment in 2013–2015, the response of organic lettuce to cover crop management and organic fertilisation, in terms of yield, nitrogen status and efficiency, was investigated. A vetch cover crop was introduced before the lettuce and was terminated by the no-till roller crimper strategy (RC), which was compared with incorporation of the vetch into the soil as green manure (GM) and with a no-vetch control (No_V). Two organic fertilisers derived from waste recycling, anaerobic digestate (AD) and municipal solid waste compost (MSW), were compared with a commercial organic fertiliser (ORG) and with a control with no fertiliser (No_F). The RC treatment resulted in high lettuce yields in both years, whereas GM showed intermediate yield values (significant differences in 2014). Crop N status reflected yield, with improved values in RC plots. At harvest, particularly in 2014, the use of vetch and fertilisers increased soil mineral nitrogen concentrations compared with those in No_V and No_F treatments, though the differences were not statistically significant. Lettuce N use efficiency (NUE) had an inverse trend to that of the yield; the lower the yield the higher the NUE. The RC in combination with the use of organic fertilisers assured a satisfactory response to the variability in weather, in terms of both yield stability and preservation of soil fertility.

中文翻译：

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有机生菜的农业生态实践：对产量、氮素状况和氮素利用效率的影响

摘要 气候变化往往会加剧世界范围内的极端天气事件，对农业产生负面影响并威胁全球粮食安全。需要更具弹性的农业生态系统来确保产量稳定性。这项研究于 2013-2015 年在地中海环境中进行，研究了有机生菜对覆盖作物管理和有机施肥在产量、氮状况和效率方面的反应。在生菜之前引入了一种紫云英覆盖作物，并通过免耕辊卷曲策略 (RC) 终止，该策略与将紫云英作为绿肥 (GM) 掺入土壤中和与无紫菜对照 (No_V) 进行比较）。两种来自废物回收利用的有机肥料，厌氧消化物 (AD) 和城市固体废物堆肥 (MSW)，与商业有机肥料 (ORG) 和不施肥的对照 (No_F) 进行比较。RC 处理导致两年生菜产量高，而转基因显示中等产量值（2014 年有显着差异）。作物 N 状态反映了产量，RC 图中的值有所提高。在收获时，特别是在 2014 年，与 No_V 和 No_F 处理相比，野豌豆和肥料的使用增加了土壤矿质氮浓度，尽管差异没有统计学意义。生菜氮素利用效率（NUE）与产量呈相反趋势；产量越低，NUE 越高。RC 结合有机肥的使用确保了对天气变化的满意响应，无论是在产量稳定性还是土壤肥力保持方面。