A field study comparing soil profile N2O concentration with surface flux under different farming practices
| dc.contributor.author | Parastesh, Faezeh | |
| dc.contributor.examiningcommittee | Mante, Afua (Soil Science) | |
| dc.contributor.examiningcommittee | Cordeiro, Marcos (Animal Science) | |
| dc.contributor.supervisor | Gao, Xiaopeng | |
| dc.contributor.supervisor | Tenuta, Mario | |
| dc.date.accessioned | 2024-09-13T19:16:44Z | |
| dc.date.available | 2024-09-13T19:16:44Z | |
| dc.date.issued | 2024-08-02 | |
| dc.date.submitted | 2024-09-13T18:52:51Z | en_US |
| dc.degree.discipline | Soil Science | |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | Existing research has consistently demonstrated a significant increase in N2O emissions during the spring thaw period. However, understanding the precise influence of farming practices such as cover crops and enhanced efficiency nitrogen fertilizers (EENFs) on N2O dynamics—production, diffusion, consumption in the soil profile, and surface emissions—remains limited, particularly in clay soil in Manitoba. A two-year field study was conducted in 2022 and 2023 on clay soil at the TGAS-MAN research station in Manitoba to investigate the impact of different farming practices [cover crop and enhanced efficient nitrogen fertilizers (EENFs)] on soil profile N2O concentrations at 5, 15, 30 and 60 cm of soil profile in relation to surface flux. The research site was divided into four 4-hectare fields, each measuring 200 meters by 200 meters. Six modified silicone diffusive equilibrium samplers were installed in each field to collect soil profile gas samples from different depths. The micrometeorological method was used to measure N2O surface flux rates. The results indicated that growing winter rye as a cover crop significantly (p<0.01) decreased soil profile N2O concentrations across all depths from September to December. Compared to non-cover crop, the cover crop treatment decreased the median N2O concentrations at 5, 15, 30, and 60 cm. With the increasing temperature and soil moisture at spring–thaw, profile N2O concentrations at all depths increased significantly. In contrast, no significant difference was observed between the non-cover and cover crop treatments during spring–thaw. While different fertilizer sources did not significantly affect N2O concentrations, EENF demonstrated a capacity to reduce N2O concentration in the 5 cm depth but did not have a discernible effect at deeper depths during the growing season 2023. The lowest N2O concentrations were consistently observed at shallow depths (5 cm) throughout the study period, while peak N2O concentrations were observed at deeper soil depths (30-60 cm). The peak N2O concentration during spring–thaw 2022 and 2023 occurred at 30 cm of soil profile likely due to higher microbial activity, confirming that de novo production is the main mechanism driving N2O peak emission during spring–thaw. | |
| dc.description.note | October 2024 | |
| dc.identifier.uri | http://hdl.handle.net/1993/38595 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Enhanced efficient nitrogen fertilizers | |
| dc.subject | Spring-thaw | |
| dc.subject | Cover Crop | |
| dc.subject | Silicone diffusive equilibrium samplers | |
| dc.title | A field study comparing soil profile N2O concentration with surface flux under different farming practices | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | |
| project.funder.name | Research Manitoba New Investigator Operating Grants |