Author
KOIDE, ROGER - Brigham Young University - Idaho | |
NGUYEN, BIHN - Ho Chi Minh City University Of Technology | |
SKINNER, HOWARD - Retired ARS Employee | |
Dell, Curtis | |
Adler, Paul | |
DROHAN, PATRICK - Pennsylvania State University | |
LICHT, MEGAN - Brigham Young University - Idaho | |
BOYER MATTHEWS, MONICA - Brigham Young University - Idaho | |
NETTLES, RACHEL - Brigham Young University - Idaho | |
RICKS, KEVIN - Brigham Young University - Idaho | |
WATKINS, JOHN - Brigham Young University - Idaho |
Submitted to: BioEnergy Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/25/2018 Publication Date: 12/1/2018 Citation: Koide, R., Nguyen, B., Skinner, H., Dell, C.J., Adler, P.R., Drohan, P., Licht, M., Boyer Matthews, M., Nettles, R., Ricks, K., Watkins, J. 2018. Comparing Biochar application methods for switchgrass yield and C sequestration on contrasting marginal lands in Pennsylvania, USA. BioEnergy Research. 11(4):784-802. https://doi.org/10.1007/s12155-018-9940-1. DOI: https://doi.org/10.1007/s12155-018-9940-1 Interpretive Summary: Marginally productive lands that are not well suited for growing grains or livestock feed provide the opportunity to grow biomass for biofuel production without competing with food production. Switchgrass is well suited for as a biofuel feedstock because it produces large quantities of biomass with limited inputs even with poor growing conditions. The biochar that is a by-product of biofuel production can be used as a soil amendment with the potential to improve soil properties and increase crop yield. A five-year field study was conducted at four sites (two were poorly drained and two were drought prone) to determine if adding about 5 tons of biochar per acre could increase switchgrass biomass yield. The biochar was either applied all at once and rotilled into the soil before switchgrass was planted, or 1.25 ton of biochar was applied in trenches between switchgrass rows each year for four years. Rototilling in the full amount of biochar before planting switchgrass increased switchgrass yield by an average of 8%, but trenching in biochar each year for four years did not increase switchgrass yield. Therefore, we can recommend biochar application prior to establishment as an effective means to increase switchgrass biomass productivity on marginal lands Technical Abstract: In order for biofuels to fulfill the US renewable fuel standard, much of the feedstock may have to be grown on marginal lands to avoid competition with food crops. Switchgrass is a candidate biofuel feedstock because it grows relatively well under suboptimal conditions with few inputs. With respect to C sequestration, however, switchgrass may be inferior to vegetation currently on marginal lands. The pyrolysis biofuel pathway produces biochar that, when added to soil, may increase crop yield while sequestering C. We grew switchgrass at four marginal sites in Pennsylvania. Two were poorly drained and two were excessively drained. We added 10 tonne per ha switchgrass biochar either by rototilling in the full amount prior to crop establishment, or by adding a quarter of the biochar in each of 4 years between crop rows using a chisel-plow. Biochar significantly increased yield in rototilled plots but not in chisel-plowed plots. Biochar also enhanced C sequestration, in some cases increasing it beyond that in the soils of vegetation normally present on the marginal land. When rototilled into the soil, biochar had no significant impact or only marginal impact on mycorrhizal colonization of roots, soil bacterial and fungal communities, soil enzyme activity, and earthworm activity. We conclude that biochar may be part of an effective strategy for switchgrass production on marginal lands, resulting in increased yield and C sequestration without negative impacts on important components of the soil ecosystem. |