CenUSA Bioenergy is an ambitious Iowa State University-based, USDA National Institute of Food and Agriculture (NIFA) sponsored, research project investigating the creation of a Midwestern sustainable biofuels and bioproducts system. As part of this project, CenUSA is supporting biochar research. Published research findings include:

Determined that oxonium groups (oxygen heterocycles) are the source of pH independent positive charge on biochar surfaces, hence the source of anion exchange capacity, and showed that oxonium groups in bridging positions are stable against weathering. ^{3, 7}

Determined that the original Boehm titration method for determining surface change does not work with biochars because of interference from soluble ash and organic compounds in biochar and developed a modified Boehm titration method that does work with biochars. ^{1, 9}

Developed a biochar module within the APSIM cropping system model that predicts the impact of biochar amendments on crop yields and environmental outcomes, such as CO₂ and N₂O emissions and NO_3- leaching. ⁴

A simplified diagram illustrating APSIM’s soil carbon (top left panel), soil nitrogen (bottom left panel), soil water (top right panel) and crop (bottom right panel) modules. Boxes are state variable, solid arrows are rate variables and indicate material flow (e.g. carbon), broken arrows indicate information flow (e.g. priming), and circles are intermediate variables. Driving variables for the system (green circles at the top) include weather, soil, crop, and management. Shown in red are the state, rate, and intermediate variables that we hypothesize to be influenced by biochar amendments. Abbreviations: RES: surface residue; FOM: fresh organic matter; BIOM: microbial pool; HUM: humic pool; INERT: inert pool; SAT: saturation point; DUL and LL: drained upper and lower limits; KL: parameter defining the ability of the roots to take up water; CEC: cation exchange capacity; and BD:.

Graphics from:  Archontoulis, S.V., I. Huber, F.E. Miguez, P.J. Thorburn, and D.A. Laird. 2016. A model for mechanistic and system assessments of biochar effects on soils and crops and trade-offs.  GCB Bioenergy. doi: 10.1111/gcbb.12314.

Determined that both feedstock and peak pyrolysis temperature influence the changes in biochar surface chemistry that occur on aging (weathering) in soils and developed a rapid laboratory aging technique that mimics most of the processes that occur during prolonged field aging of biochar.^2,3

Graphical abstract from:  Lawrinenko, M., and D.A. Laird. 2016. Accelerated aging of biochars; impact on anion exchange capacity. Carbon. 10: 217-227.

Quantified corn crop yields and soil quality responses to biochar applications for high quality Midwestern soils.^{5, 8}

APSIM Biochar model predictions of corn grain yield, corn stover, soil bulk density (BD), soil pH, SOC (soil organic carbon) and volumetric soil moisture vs. experimental observations from Rogovska et al. (2014). The biochar was applied in November 2010 and the measurements were obtained in 2012.

For more information, contact David Laird, professor of agronomy, Iowa State University, dlaird@iastate.edu.

Biochar Refereed Publications

Supported in part by CenUSA

1. Graber, E.R., L. Tsechansky, R.B. Fidel, M.L Thompson, and D.A. Laird. 2016. Determining Acidic Groups at Biochar Surfaces via the Boehm Titration. In: Singh, B., Camps-Arbestain, M., Lehmann, J. (Eds). Methods of Biochar Analysis. CSIRO Publishing, Melbourne, Chapter 8 (in press).
2. Bakshi, S., D.M. Aller, D.A. Laird, and R. Chintala, 2016. Comparison of the Physical and Chemical Properties of Laboratory- and Field-Aged Biochars. Journal of Environmental Quality doi:10.2134/jeq2016.02.0062.
3. Lawrinenko, M., D.A. Laird, R.L. Johnson, and D. Jing. 2016. Accelerated aging of biochars; impact on anion exchange capacity. Carbon. 10: 217-227. Doi: 10.1016/j.carbon.2016.02.096
4. Archontoulis, S.V., I. Huber, F.E. Miguez, P.J. Thorburn, and D.A. Laird. 2016. A model for mechanistic and system assessments of biochar effects on soils and crops and trade-offs. GCB Bioenergy. doi: 10.1111/gcbb.12314.
5. Rogovska, N., D.A. Laird, and D.L. Karlen. 2016. Corn and Soil Response to Biochar Application and Stover Harvest. Field Crops Research. 187:96-106. (doi: 10.1016/j.fcr.2015.12.013)
6. Laird, D.A. and N.P. Rogovska. 2015. Chapter 18: Biochar effects on nutrient leaching. In J. Lehmann and S. Joseph (eds.). Biochar for Environmental Management. Earthscan. P. 519-540.
7. Lawrinenko, M. and D.A. Laird. 2015. Anion exchange Capacity of Biochar. Green Chemistry, 17 (9), 4628 – 4636. 2015, DOI: 10.1039/C5GC00828J.
8. Rogovska, N., D.A. Laird, S.J. Rathke, and D.L. Karlen. 2014. Biochar impact on Midwestern Mollisols and maize nutrient availability. Geoderma. 230:340-347.
9. Fidel, R.B., D.A. Laird, and M.L. Thompson. 2013. Evaluation of Modified Boehm Titration Methods for Use with Biochars. Journal of Environmental Quality. 42:1771-1778.
10. Allen, R.M., and D.A. Laird. 2013. Quantitative prediction of biochar soil amendments by near-infrared reflectance spectroscopy. Soil Sci. Soc. Am. J. 77:1784-1794. (doi:10.2136/sssaj2013.03.0118).
11. Basso, A.S., F.E. Miguez, D.A. Laird, R. Horton, and M. Westgate. 2013. Assessing potential of biochar for increasing water-holding capacity of sandy soils. GCB Bioenergy. 5:132–143. (doi: 10.1111/gcbb.12026).