Nitrogen (N) is an essential macronutrient for plant growth. As a widespread source of plant-available N, ammonia synthesis via the Haber-Bosch process has proven an extremely valuable commodity in farming systems since the middle of the twentieth century. However, its heavy reliance on ever-shrinking fossil fuel reserves and its sizeable carbon footprint have fostered the exploration of alternative, more sustainable, fertilising prospects. Through the recycling and reuse of nutrient byproducts, biobased fertilisers (BBF) can help reduce the European Union’s dependency on imported synthetic fertilisers. In this study, we examined digestate, the liquid fraction of digestate, pig slurry and pig urine as potential substitutes for synthetic fertilisers. In a full-scale field approach using a different crop each year (maize, spinach, potatoes), the agronomic performance of the treatments (defined as the crop N uptake and the crop yield) and the environmental performance (taken as the residual soil nitrates after harvest) of the BBF treatments were compared with those of a synthetic fertiliser benchmark (calcium ammonium nitrate) at three N regimes. As regards short-term fertilising capability, results showed that yields obtained from BBFs were not statistically different (p > 0.05) than those obtained with synthetic fertilisers. Likewise, for soil residual nitrates (0–90 cm), measured in October–November of each year, no difference (p > 0.05) was detected between the BBFs and the synthetic fertiliser reference treatments. However, the non-superiority test showed that some BBFs tended to perform better in terms of residual nitrates than the synthetic regimes. Generally, results pointed to a fast N release ability of the BBFs, indicated by the presence of nitrates at different soil depths. Hence, as with the mineral fertiliser, BBFs were prone to leaching which calls for adequate N management strategies. The N content of some BBFs were shown to vary over time, hence adequate and timely nutrient characterisations must be carried out prior to field application to ensure a more accurate N accountancy and reduce risks of over-fertilisation (or under-fertilisation).

中文翻译：

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沼渣替代合成肥料：西法兰德省作物生长性能和土壤残留硝酸盐的 3 年比较田间研究


氮 （N） 是植物生长所必需的常量营养素。作为植物性氮的广泛来源，自 20 世纪中叶以来，通过 Haber-Bosch 工艺合成氨已被证明是农业系统中极其有价值的商品。然而，它对不断萎缩的化石燃料储量的严重依赖和巨大的碳足迹促进了对替代性、更可持续、肥沃前景的探索。通过回收和再利用营养副产品，生物基肥料 （BBF） 可以帮助减少欧盟对进口合成肥料的依赖。在这项研究中，我们检查了沼渣、沼渣的液体馏分、猪粪浆和猪尿液作为合成肥料的潜在替代品。在每年使用不同作物（玉米、菠菜、马铃薯）的全面田间方法中，将 BBF 处理的农艺性能（定义为作物氮吸收和作物产量）和环境性能（以收获后残留的土壤硝酸盐）与合成肥料基准（硝酸铵钙）在三个氮方案下的农艺性能进行比较。关于短期施肥能力，结果表明，从 BBF 获得的产量与使用合成肥料获得的产量没有统计学差异 （p > 0.05）。同样，对于每年 10 月至 11 月测量的土壤残留硝酸盐 （0-90 cm），BBF 和合成肥料参考处理之间没有检测到差异 （p > 0.05）。然而，非优效性检验表明，一些 BBF 在残留硝酸盐方面的表现往往优于合成方案。 一般来说，结果表明 BBF 的快速氮释放能力，这从不同土壤深度的硝酸盐存在可以看出。因此，与矿物肥料一样，BBF 容易浸出，这需要适当的氮管理策略。一些 BBF 的 N 含量随时间变化，因此必须在田间施肥前进行充分和及时的营养表征，以确保更准确的 N 核算并降低过度施肥（或施肥不足）的风险。