EGU21-1063
https://doi.org/10.5194/egusphere-egu21-1063
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Agricultural N2O emission is influenced by N-fertilization form rather than landscape position

Shrijana Vaidya1, Reena Macagga1, Mogens Thalmann1, Nicole Jurisch1, Natalia Pehle1, Gernot Verch2, Michael Sommer3, Jürgen Augustin1, and Mathias Hoffmann1
Shrijana Vaidya et al.
  • 1Leibniz Centre for Agricultural Landscape Research (ZALF), Isotope Biogeochemistry and Gas Fluxes, Müncheberg, Germany (vaidyashriju@gmail.com)
  • 2Leibniz Centre for Agricultural Landscape Research (ZALF), Experimental Infrastructure Platform, Steinfurther Straße 14, 17291 Prenzlau, Germany
  • 3Leibniz Center for Agricultural Landscape Research (ZALF), Landscape Pedology, Eberswalder Str. 84, 15374 Müncheberg, Germany

Agricultural soils are an important source of nitrous oxide (N2O) emission and are mainly affected by the application of N fertilization. In addition to the effect of fertilizer form (mineral/organic), N2O production and consumption processes in agricultural systems are influenced by the soil characteristics. However, knowledge of this is still very limited for erosion-affected arable soils. Therefore, the aim of our investigations was to find the impact of soil erosion state associated with the landscape position and N fertilization form have on N2O emission. This information is needed to evaluate the effects/benefits of new agricultural practices in future mitigation strategies aiming towards lower N2O emissions.

We present 3 years of N2O flux measurements in a two-factorial experiment by using a non-flow-through non-steady-state (NFT-NSS) manual chambers. Three sites were established on the summit position having similar soil type (Albic Luvisols; non-eroded soil) and were treated with organic fertilizer (100% organic biogas fermented residues (BFR)), mineral fertilizer (100% mineral calcium ammonium nitrate (CAN)), and a mixture of both fertilizers (50% CAN + 50% BFR). Two additional sites were established on the extremely eroded soil (Calcaric Regosols; on a steep slope with very dense parent material) and at a colluvial site in a depression (Endogleyic Colluvic Regosols) and treated with 100% CAN. The crop rotation was identical for all sites during the study period which includes: Maize (Zea mays L.) – Maize (Zea mays L.) – ­Winter rye (Secale cereale L.) – Sorghum (Sorghum bicolor) – Triticale (Triticosecale).

Our results show that the N2O emission exhibited temporal and spatial variability and is mainly influenced by fertilization form and soil type. Among the three fertilization treatments within the same soil type (non-eroded soil), the site with the application of organic fertilization shows the highest cumulated N2O emission which is accumulated to 13.5 kg N2O-N ha-1 compared to the site with mixed fertilization (11.4 kg N2O-N ha-1) and mineral fertilization (4.5 kg N2O-N ha-1). Among the three distinct soil types with an identical application of mineral fertilizer, the cumulated N2O emission is higher at the depression (7.3 kg N2O-N ha-1) compared to the non-eroded (4.5 kg N2O-N ha-1) and extremely eroded soil (1.6 kg N2O-N ha-1). In general, our results suggest a stronger influence of N fertilization form than erosion affected soil on N2O emission.

Keywords: NFT-NSS manual chamber; soil erosion; N fertilization form, nitrous oxide, soil type

How to cite: Vaidya, S., Macagga, R., Thalmann, M., Jurisch, N., Pehle, N., Verch, G., Sommer, M., Augustin, J., and Hoffmann, M.: Agricultural N2O emission is influenced by N-fertilization form rather than landscape position, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1063, https://doi.org/10.5194/egusphere-egu21-1063, 2021.

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