The special issue summarises and highlights key findings of the research unit DASIM funded by the German Research Foundation (DFG) on the process of denitrification. Progress was made in several areas including the development of new and advanced methods to quantify N 2 fluxes such as a new 15 N gas flux method, enhanced Raman spectroscopy and a new incubation system to study plant-soil interactions in He-O 2 atmosphere. Under...

The objectives of this field trial were to collect reliable measurement data on N 2 emissions and N 2 O/(N 2 O + N 2 ) ratios in typical German crops in relation to crop development and to provide a dataset to test and improve biogeochemical models. N 2 O and N 2 emissions in winter wheat (WW, Triticum aestivum L.) and sugar beet (SB, Beta vulgaris subsp. vulgaris ) were measured using the improved 15 N gas flux method with he...

The 15 N gas flux ( 15 NGF) method allows for direct in situ quantification of dinitrogen (N 2 ) emissions from soils, but a successful cross-comparison with another method is missing. The objectives of this study were to quantify N 2 emissions of a wheat rotation using the 15 NGF method, to compare these N 2 emissions with those obtained from a lysimeter-based 15 N fertilizer mass balance approach, and to contextualize N 2 em...

The fertiliser growth response of planted forests can vary due to differences in site-specific factors like climate and soil fertility. We identified when forest stands responded to a standard, single application of nitrogen (N) fertiliser and employed a machine learning random forest model to test the use of natural abundance stable isotopic N (δ 15 N) to predict site response. Pinus radiata growth response was calculated as...

European policy recommends that biomass production occur on marginal land, such as poorly draining Stagnosols. Compared to annual cropping, perennial crops may better mitigate N 2 O emissions at such sites, through more complete denitrification. To test that hypothesis, we compared N 2 and N 2 O fluxes from the soils of a perennial crop (cup plant, Silphium perfoliatum L.) and an annual crop (silage maize, Zea mays L.). Intact...

Although the canopy can play an important role in forest nutrient cycles, canopy‐based processes are often overlooked in studies on nutrient deposition. In areas of nitrogen (N) and phosphorus (P) deposition, canopy soils may retain a significant proportion of atmospheric inputs, and also receive indirect enrichment through root uptake followed by throughfall or recycling of plant litter in the canopy. We measured net and gros...