Abstract
Nitrous oxide (N(2)O) 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 N(2)O 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 N(2)O emissions. We investigated N(2)O fluxes along a transect in six agriculturally used patches (0.52 ha) with varying texture, yield potential and crop rotation. We measured N(2)O 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 N(2)O emissions and were mostly driven by soil physical properties. On a small scale, soil texture and environment determined spatial heterogeneity of N(2)O emissions being more pronounced for sandier soils. On patch level, N(2)O 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 N(2)O 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.