Wood mulch is the preferred organic amendment for mitigating N2O emissions while shielding cultivated organic soil from aeolian erosion
Citation
Ross-Blevis L., Pelster D., Masse J., Whalen J.K. 2023. Wood mulch is the preferred organic amendment for mitigating N2O emissions while shielding cultivated organic soil from aeolian erosion. Oral presentation. CSSS annual meeting, Truro, Canada, June 26th to June 29th 2023.
Plain language summary
Application of organic mulch can mitigate erosion of arable organic soils. However, mulch application may stimulate microbial activity and denitrification, the dominant source of nitrous oxide (N2O) emited from arable organic soils. This study compared N2O emissions following application of mulches to arable organic soils under letuce production in Sainte-Clotilde, Québec. The experiment was designed with mulch (switchgrass, miscanthus, ash, larch, willow), fall-seeded rye, no-till, and bare fallow. During two field seasons (May-October 2021 and 2022), we assessed N2O, CO2, and CH4 flux, soil moisture and temperature, and NH4 and NO3 availability. Wood mulch produced similar cumulative N2O emissions, and grass mulch produced more N2O emissions, than the control. This was related to the higher C:N ratio of wood mulch, which affected microbial activity and denitrification.
Abstract
Application of organic mulch can mitigate erosion of arable organic soils. However, mulch application may stimulate microbial activity and denitrification, the dominant source of nitrous oxide (N2O) emited from arable organic soils. This study compared N2O emissions following application of mulches to arable organic soils under letuce production in Sainte-Clotilde, Québec. The experiment was designed with mulch (switchgrass, miscanthus, ash, larch, willow), fall-seeded rye, no-till, and bare fallow. During two field seasons (May-October 2021 and 2022), we assessed N2O, CO2, and CH4 flux, soil moisture and temperature, and NH4 and NO3 availability. Wood mulch produced similar cumulative N2O emissions, and grass mulch produced more N2O emissions, than the control. This was related to the higher C:N ratio of wood mulch, which affected microbial activity and denitrification.