Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate
The potential of switchgrass (Panicum virgatum L.) to offset large-scale greenhouse gas (GHG) emissions depends on optimizing external inputs when the crop is primarily managed as a sustainable source for renewable energy production. Due to the heterogeneity of climate and soil conditions and the co...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Published: |
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/75591 |
| _version_ | 1848763509625585664 |
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| author | Lee, Juhwan Pedroso, G. van Kessel, C. Six, J. |
| author_facet | Lee, Juhwan Pedroso, G. van Kessel, C. Six, J. |
| author_sort | Lee, Juhwan |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The potential of switchgrass (Panicum virgatum L.) to offset large-scale greenhouse gas (GHG) emissions depends on optimizing external inputs when the crop is primarily managed as a sustainable source for renewable energy production. Due to the heterogeneity of climate and soil conditions and the complexity of agriculture, an evaluation of the effect of adopting switchgrass as a new biofuel crop into agriculture needs to be done at the regional scale. The objective of the study was to predict long-term (100-yr) GHG emissions under different N fertilization (0, 112, and 224 kg N ha−1) and irrigation application (0, 25, 50, 75, and 99 cm H2O) levels across the Central Valley of California using the DAYCENT model. Six cultivars (Alamo, Kanlow, Cave-in-Rock, Blackwell, Sunburst, and Trailblazer) were selected. The model results suggest that switchgrass productivity is primarily constrained by N inputs when no or low water stress is expected in a Mediterranean climate. In the short-term (the first decade after establishment), soil organic carbon (SOC) stocks (0–20 cm) increased by 0.42–0.92 Mg C ha−1 yr−1 and N2O emissions were 1.37–2.48 kg N2O–N ha−1 yr−1 across the cultivars with baseline input rates of 224 kg N ha−1 yr−1 and 99 cm H2O. All cultivars were net CO2 sinks in the near term and the potential decreased by 0.09–0.30 Mg C ha−1 yr−1 (15.5–52.8%) with reduced N input from baseline under varying irrigation rates. There was a reduction in N2O emissions by 47.2–61.6% by applying less N fertilizer when irrigated at rates ≥75 cm H2O per year over time. In general, higher-yielding cultivars (e.g., Alamo) tended to sequester more CO2 but also led to higher N2O emissions. In the near term, the use of N fertilizer and irrigation is needed for switchgrass systems to be a soil GHG sink, but for longer-term GHG mitigation strategies reducing both N fertilization and irrigation inputs is required. |
| first_indexed | 2025-11-14T11:04:36Z |
| format | Journal Article |
| id | curtin-20.500.11937-75591 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T11:04:36Z |
| publishDate | 2015 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-755912019-05-29T03:15:42Z Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate Lee, Juhwan Pedroso, G. van Kessel, C. Six, J. The potential of switchgrass (Panicum virgatum L.) to offset large-scale greenhouse gas (GHG) emissions depends on optimizing external inputs when the crop is primarily managed as a sustainable source for renewable energy production. Due to the heterogeneity of climate and soil conditions and the complexity of agriculture, an evaluation of the effect of adopting switchgrass as a new biofuel crop into agriculture needs to be done at the regional scale. The objective of the study was to predict long-term (100-yr) GHG emissions under different N fertilization (0, 112, and 224 kg N ha−1) and irrigation application (0, 25, 50, 75, and 99 cm H2O) levels across the Central Valley of California using the DAYCENT model. Six cultivars (Alamo, Kanlow, Cave-in-Rock, Blackwell, Sunburst, and Trailblazer) were selected. The model results suggest that switchgrass productivity is primarily constrained by N inputs when no or low water stress is expected in a Mediterranean climate. In the short-term (the first decade after establishment), soil organic carbon (SOC) stocks (0–20 cm) increased by 0.42–0.92 Mg C ha−1 yr−1 and N2O emissions were 1.37–2.48 kg N2O–N ha−1 yr−1 across the cultivars with baseline input rates of 224 kg N ha−1 yr−1 and 99 cm H2O. All cultivars were net CO2 sinks in the near term and the potential decreased by 0.09–0.30 Mg C ha−1 yr−1 (15.5–52.8%) with reduced N input from baseline under varying irrigation rates. There was a reduction in N2O emissions by 47.2–61.6% by applying less N fertilizer when irrigated at rates ≥75 cm H2O per year over time. In general, higher-yielding cultivars (e.g., Alamo) tended to sequester more CO2 but also led to higher N2O emissions. In the near term, the use of N fertilizer and irrigation is needed for switchgrass systems to be a soil GHG sink, but for longer-term GHG mitigation strategies reducing both N fertilization and irrigation inputs is required. 2015 Journal Article http://hdl.handle.net/20.500.11937/75591 10.1016/j.agee.2015.06.015 restricted |
| spellingShingle | Lee, Juhwan Pedroso, G. van Kessel, C. Six, J. Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate |
| title | Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate |
| title_full | Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate |
| title_fullStr | Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate |
| title_full_unstemmed | Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate |
| title_short | Potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a Mediterranean climate |
| title_sort | potential regional productivity and greenhouse gas emissions of fertilized and irrigated switchgrass in a mediterranean climate |
| url | http://hdl.handle.net/20.500.11937/75591 |