Intercropping with Switchgrass Improves Net Greenhouse Gas Balance in Hybrid Poplar Plantations on a Sand Soil
| Autor: | Harold P. Collins, Steven C. Fransen, Emi Kimura, P.A. Fay, Austin Himes |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Irrigation
biology 020209 energy Soil Science Biomass Intercropping 04 agricultural and veterinary sciences 02 engineering and technology engineering.material biology.organism_classification Agronomy Bioenergy Greenhouse gas 040103 agronomy & agriculture 0202 electrical engineering electronic engineering information engineering engineering 0401 agriculture forestry and fisheries Panicum virgatum Environmental science Fertilizer Monoculture |
| Zdroj: | Soil Science Society of America Journal. 81:781-795 |
| ISSN: | 0361-5995 |
| Popis: | In the Pacific Northwest, commercial hybrid poplar (Populus generosa Henry × Populus canadensis Moench.) is managed at low stocking densities under irrigation for high-value timber production. The objectives of this study were to measure greenhouse gas emissions (CH4, CO₂, and N₂O) during intercropping of switchgrass (Panicum virgatum L.) with hybrid poplar; estimate losses of fertilizer-N as N₂O, and estimate global warming potentials (GWP) of the intercrop. Cumulative above-ground biomass-C of the poplar monoculture (PM) closely matched the four year growing season (GS) soil CO₂–C emissions, where aboveground biomass of the switchgrass monoculture (SM) and intercrop (IC) exceeded GS CO₂–C emissions by 14.1 Mg C ha⁻¹. Soil CH₄–C uptake was not significantly different between treatments, while GS N₂O-N emissions for PM were ∼80% lower than both IC and SM. N₂O emissions factors averaged 0.7% of the applied N-fertilizer. Cumulative contributions of CO₂ emissions to GWP were offset by biomass-C resulting in a near zero balance (−5.1 Mg CO₂ₑq ha ⁻¹) for the PM, where, IC and SM sequestered significantly more CO₂ resulting in a net GWP of −42.5 and –32.2 Mg CO₂ₑq ha⁻¹, respectively. Intercropping with switchgrass can improve the net greenhouse gas balance of hybrid poplar. Continued research is needed on the effects of irrigated bioenergy production on GHG emissions in intercropped systems as they will become increasingly important as agricultural water use, water availability and quality are challenged by climate change. |
| Databáze: | OpenAIRE |
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