2024/04/04 by Jonas Eckei, Reinhard Well, Martin Maier +3 · 1 voice
Environmental Science · Agricultural and Biological Sciences · #Isotope Analysis in Ecology #Crop Yield and Soil Fertility
paper · pdf · doi:10.1007/s00374-024-01806-z
openalex publication_date 2024/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Abstract 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 helium–oxygen flushing (80:20) to reduce the atmospheric N 2 background to < 2%. To estimate total N 2 O and N 2 production in soil, production-diffusion modelling was applied. Soil samples were taken in regular intervals and analyzed for mineral N (NO 3 − and NH 4 + ) and water-extractable Corg content. In addition, we monitored soil moisture, crop development, plant N uptake, N transformation processes in soil, and N translocation to deeper soil layers. Our best estimates for cumulative N 2 O + N 2 losses were 860.4 ± 220.9 mg N m −2 and 553.1 ± 96.3 mg N m −2 over the experimental period of 189 and 161 days with total N 2 O/(N 2 O + N 2 ) ratios of 0.12 and 0.15 for WW and SB, respectively. Growing plants affected all controlling factors of denitrification, and dynamics clearly differed between crop species. Overall, N 2 O and N 2 emissions were highest when plant N and water uptake were low, i.e., during early growth stages, ripening, and after harvest. We present the first dataset of a plot-scale field study employing the improved 15 N gas flux method over a growing season showing that drivers for N 2 O and N 2 O + N 2 fluxes differ between crop species and change throughout the growing season.