Zentgraf Isabel, Holz Maire, Monzón Díaz Oscar Rodrigo, Lück Matthias, Kramp Katja, Pusch Valerie, Grahmann Kathrin, Hoffmann Mathias
Working Group of Isotope Biogeochemistry and Gas Fluxes, Leibniz Centre for Agricultural Landscape Research (ZALF) e.V., Eberswalder Straße 84, 15374, Müncheberg, Germany.
Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10099, Berlin, Germany.
Sci Rep. 2025 Mar 31;15(1):11013. doi: 10.1038/s41598-025-95630-6.
Nitrous oxide (NO) emissions from agricultural soils vary due to factors such as soil organic matter, soil moisture, and crop type, leading to short-term variations and concentrated zones of high emissions, known as "hot moments" and "hotspots." These peaks, occurring at various scales, contribute significantly to total NO emissions. This is particularly relevant for sandy soils, where high porosity and low water-holding capacity promote gas diffusion and create moisture variability, leading to highly heterogeneous NO emissions. We investigated NO fluxes along a transect in six agriculturally used patches (0.52 ha) with varying texture, yield potential and crop rotation. We measured NO fluxes bi-weekly over 2 years, using a non-flow-through non-steady-state (NFT-NSS) manual closed chamber system, covering different crops and weather conditions. Hot moments accounted for 6-71% of total crop NO emissions and were mostly driven by soil physical properties. On a small scale, soil texture and environment determined spatial heterogeneity of NO emissions being more pronounced for sandier soils. On patch level, NO emissions differed more strongly than on microplot level and were mainly driven by crop-type and management. Our findings highlight the importance of accounting for intrinsic variability in soil texture, topography, and microclimate within patches. Additionally, broader differences across management-influenced patches must be considered to better understand the drivers of NO emissions. This dual-scale approach emphasizes the need for high-resolution soil monitoring for mitigation strategies and to refine models. At the same time, it guides farmers toward soil-specific fertilization to reduce emissions and maintain yields in diverse agricultural landscapes.
农业土壤中的一氧化二氮（NO）排放因土壤有机质、土壤湿度和作物类型等因素而有所不同，导致短期变化以及高排放集中区，即所谓的“热时刻”和“热点”。这些在不同尺度上出现的排放峰值对NO总排放量有显著贡献。这对于沙质土壤尤为重要，因为其高孔隙率和低持水量促进了气体扩散并造成了湿度变化，导致NO排放高度不均一。我们在六个不同质地、产量潜力和作物轮作的农业用地斑块（0.52公顷）中沿着一条样带调查了NO通量。我们使用非流通非稳态（NFT-NSS）手动封闭箱系统，在两年内每两周测量一次NO通量，涵盖了不同作物和天气条件。“热时刻”占作物NO总排放量的6%-71%，主要由土壤物理性质驱动。在小尺度上，土壤质地和环境决定了NO排放的空间异质性，在沙质土壤中更为明显。在斑块层面，NO排放的差异比小区层面更为显著，主要由作物类型和管理方式驱动。我们的研究结果突出了考虑斑块内土壤质地、地形和小气候内在变异性的重要性。此外，必须考虑受管理影响的斑块之间更广泛的差异，以便更好地理解NO排放的驱动因素。这种双尺度方法强调了为制定减排策略和完善模型而进行高分辨率土壤监测的必要性。同时，它指导农民进行因地制宜的施肥，以减少排放并在多样化的农业景观中维持产量。
