Garnier Josette, Billen Gilles, Aguilera Eduardo, Lassaletta Luis, Einarsson Rasmus, Serra João, Cameira Maria do Rosário, Marques-Dos-Santos Claudia, Sanz-Cobena Alberto
SU CNRS EPHE, Umr Metis 7619, 4 Place Jussieu, 75005, Paris, France.
SU CNRS EPHE, Umr Metis 7619, 4 Place Jussieu, 75005, Paris, France.
J Environ Manage. 2023 Jul 1;337:117732. doi: 10.1016/j.jenvman.2023.117732. Epub 2023 Mar 20.
Ammonia (NH) volatilization, nitrous oxide (NO) emissions, and nitrate (NO) leaching from agriculture cause severe environmental hazards. Research studies and mitigation strategies have mostly focused on one of these nitrogen (N) losses at a time, often without an integrated view of the agro-food system. Yet, at the regional scale, NO, NH, and NO loss patterns reflect the structure of the whole agro-food system. Here, we analyzed at the resolution of NUTS2 administrative European Union (EU) regions, N fluxes through the agro-food systems of a Temperate-Mediterranean gradient (France, Spain, and Portugal) experiencing contrasting climate and soil conditions. We assessed the atmospheric and hydrological N emissions from soils and livestock systems. Expressed per ha agricultural land, NH volatilization varied in the range 6.2-44.4 kg N ha yr, NO emission and NO leaching 0.3-4.9 kg N ha yr and 5.4-154 kg N ha yr respectively. Overall, lowest NO emission was found in the Mediterranean regions, where NO leaching was greater. NH volatilization in both temperate and Mediterranean regions roughly follows the distribution of livestock density. We showed that these losses are also closely correlated with the level of fertilization intensity and agriculture system specialization into either stockless crop farming or intensive livestock farming in each region. Moreover, we explored two possible future scenarios at the 2050 horizon: (1) a scenario based on the prescriptions of the EU-Farm-to-Fork (F2F) strategy, with 25% of organic farming, 10% of land set aside for biodiversity, 20% reduction in N fertilizers, and no diet change; and (2) a hypothetical agro-ecological (AE) scenario with generalized organic farming, reconnection of crop and livestock farming, and a healthier human diet with an increase in the share of vegetal protein to 65% (i.e., the Mediterranean diet). Results showed that the AE scenario, owing to its profound reconfiguration of the entire agro-food system would have the potential for much greater reductions in NH, NO, and NO emissions, namely, 60-81% reduction, while the F2F scenario would only reach 24-35% reduction of N losses.
农业中氨（NH₃）挥发、一氧化二氮（N₂O）排放以及硝酸盐（NO₃⁻）淋失会造成严重的环境危害。研究和缓解策略大多一次只关注这些氮（N）损失中的一种，往往缺乏对农业 - 食品系统的整体认识。然而，在区域尺度上，N₂O、NH₃和NO₃⁻的损失模式反映了整个农业 - 食品系统的结构。在此，我们以欧盟（EU）NUTS2行政区为分辨率，分析了经历不同气候和土壤条件的温带 - 地中海梯度地区（法国、西班牙和葡萄牙）农业 - 食品系统中的氮通量。我们评估了土壤和畜牧系统的大气和水文氮排放。以每公顷农业用地计算，NH₃挥发量在6.2 - 44.4千克氮/公顷·年范围内变化，N₂O排放量和NO₃⁻淋失量分别为0.3 - 4.9千克氮/公顷·年和5.4 - 154千克氮/公顷·年。总体而言，地中海地区的N₂O排放量最低，但其NO₃⁻淋失量更大。温带和地中海地区的NH₃挥发大致遵循畜牧密度分布。我们表明，这些损失还与施肥强度水平以及各地区农业系统向无畜作物种植或集约化畜牧养殖的专业化程度密切相关。此外，我们探索了2050年的两种可能未来情景：（1）基于欧盟“从农场到餐桌”（F2F）战略规定的情景，即25%的有机农业、10%的土地用于生物多样性保护、氮肥减少20%且饮食无变化；（2）一种假设的农业生态（AE）情景，即普遍采用有机农业、重新连接作物种植和畜牧养殖，以及更健康的人类饮食，植物蛋白占比增加到65%（即地中海饮食）。结果表明，由于对整个农业 - 食品系统进行了深刻重构，AE情景有可能大幅减少NH₃、N₂O和NO₃⁻排放，即减少60 - 81%，而F2F情景仅能使氮损失减少24 - 35%。
