Browsing by Author "Miguez, Fernando E."

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    Global land-use and carbon emission implications from biochar application to cropland in the United States
    (Elsevier, 2020-06) Dumortier, Jerome; Dokoohaki, Hamze; Elobeid, Amani; Hayes, Dermot J.; Laird, David; Miguez, Fernando E.; School of Public and Environmental Affairs
    Biochar has the potential to increase crop yields when applied to agricultural land. We integrate agronomic and economic simulation models to determine the expected yield increase from biochar applications in the United States. We calculate the location-specific willingness to pay of U.S. farmers to apply biochar to their cropland if biochar increases yields over 20 years. In addition to the potential benefit of higher revenue for farmers, biochar applications also have policy implications if biochar production is combined with bio-fuel production or used to reduce greenhouse gas emissions from indirect land-use change. Thus, the results are then combined with an agricultural outlook model to determine the effects on global land-use change and net carbon emissions. Our results indicate that biochar application is most profitable for croplands in the Southeast U.S. due to the combination of high yield increases and availability of biomass to produce biochar. An increase in U.S. yields above trend by 1% for corn, soybeans, and wheat would decrease net total global emissions by 25–87 Tg of CO2-equivalent.
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    Where should we apply biochar?
    (IOP, 2019) Dokoohaki, Hamze; Miguez, Fernando E.; Dumortier, Jerome; School of Public and Environmental Affairs
    The heating of biomass under low-oxygen conditions generates three co-products, bio-oil, biogas, and biochar. Bio-oil can be stabilized and used as fuel oil or be further refined for various applications and biogas can be used as an energy source during the low-oxygen heating process. Biochar can be used to sequester carbon in soil and has the potential to increase crop yields when it is used to improve yield-limiting soil properties. Complex bio-physical interactions have made it challenging to answer the question of where biochar should be applied for the maximum agronomic and economic benefits. We address this challenge by developing an extensive informatics workflow for processing and analyzing crop yield response data as well as a large spatial-scale modeling platform. We use a probabilistic graphical model to study the relationships between soil and biochar variables and predict the probability and magnitude of crop yield response to biochar application. Our results show an average increase in crop yields ranging from 4.7% to 6.4% depending on the biochar feedstock and application rate. Expected yield increases of at least 6.1% and 8.8% are necessary to cover 25% and 10% of US cropland with biochar. We find that biochar application to crop area with an expected yield increase of at least 5.3%–5.9% would result in carbon sequestration offsetting 0.57%–0.67% of US greenhouse gas emissions. Applying biochar to corn area is the most profitable from a revenue perspective when compared to soybeans and wheat because additional revenues accrued by farmers are not enough to cover the costs of biochar applications in many regions of the United States.