Namoi Nictor, Lin Cheng-Hsien, Jang Chunhwa, Wasonga Daniel, Zumpf Colleen, Arshad Muhammad Umer, Heaton Emily, Lee DoKyoung
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Agroecosystem Sustainability Center, Institute for Sustainability, Energy, and Environment, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
J Environ Qual. 2025 May-Jun;54(3):576-589. doi: 10.1002/jeq2.70025. Epub 2025 Apr 22.
Purpose-grown perennial herbaceous species are nonfood crops specifically cultivated for bioenergy production and have the potential to secure bioenergy feedstock resources while enhancing ecosystem services. This study assessed soil greenhouse gas emissions (CO and NO), nitrate (NO-N) leaching reduction potential, evapotranspiration (ET), and water-use efficiency (WUE) of bioenergy switchgrass (Panicum virgatum L.) in comparison to corn (Zea mays L.). The study was conducted on field-scale plots in Urbana, IL, during the 2020-2022 growing seasons. Switchgrass was established in 2020 and urea-fertilized at 56 kg N ha year. Corn management followed best management practices for the US Midwest, including no-till and 202 kg N ha year fertilization, applied as urea-ammonium nitrate (32%). Our results showed lower direct NO emissions in switchgrass compared to corn. Although soil CO emissions did not differ significantly during the establishment year, emissions in subsequent years were over 50% higher in switchgrass than in corn, likely due to increased belowground biomass, which was over five times higher in switchgrass. Nitrate-N leaching decreased as the switchgrass stand matured, reaching 80% lower than in corn by the third year. Differences in ET and WUE between corn and switchgrass were not significant; however, results indicate a trend toward reduced WUE in switchgrass under drought, driven by lower aboveground biomass production. Our study demonstrates that switchgrass can be implemented at a commercial scale without negatively impacting the hydrological cycle, while potentially reducing N losses through nitrate-N leaching and soil NO emissions, and enhancing belowground C storage.
专门种植的多年生草本植物是非粮食作物，专为生物能源生产而培育，有潜力在增强生态系统服务的同时确保生物能源原料资源。本研究评估了与玉米（Zea mays L.）相比，生物能源柳枝稷（Panicum virgatum L.）的土壤温室气体排放（CO和NO）、硝酸盐（NO-N）淋溶减少潜力、蒸散量（ET）和水分利用效率（WUE）。该研究于2020 - 2022年生长季节在伊利诺伊州厄巴纳的田间尺度地块上进行。柳枝稷于2020年种植，每年施尿素氮肥56 kg N ha 。玉米管理遵循美国中西部的最佳管理实践，包括免耕和每年施202 kg N ha肥料，以硝酸铵尿素（32%）的形式施用。我们的结果表明，与玉米相比，柳枝稷的直接NO排放量更低。虽然在种植当年土壤CO排放量没有显著差异，但在随后几年中，柳枝稷的排放量比玉米高出50%以上，这可能是由于地下生物量增加，柳枝稷的地下生物量比玉米高出五倍多。随着柳枝稷林分成熟，硝酸盐 - N淋溶减少，到第三年比玉米低80%。玉米和柳枝稷之间的ET和WUE差异不显著；然而，结果表明，在干旱条件下，柳枝稷的WUE有降低的趋势，这是由地上生物量产量较低驱动的。我们的研究表明，柳枝稷可以在商业规模上实施，而不会对水文循环产生负面影响，同时有可能通过硝酸盐 - N淋溶和土壤NO排放减少氮损失，并增强地下碳储存。
