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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Soil, Water & Air Resources Research » Research » Publications at this Location » Publication #325887
Title: Impact of six lignocellulosic biochars on C and N dynamics of two contrasting soils

Author
item FIDEL, RIVKA - Iowa State University
item LAIRD, DAVID - Iowa State University
item Parkin, Timothy

Submitted to: Global Change Biology Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2017
Publication Date: 7/1/2017
Citation: Fidel, R.B., Laird, D.A., Parkin, T.B. 2017. Impact of six lignocellulosic biochars on C and N dynamics of two contrasting soils. Global Change Biology Bioenergy. 9:1279-1291. doi: 10.1111/gcbb.12414.

Interpretive Summary: Biochar is a byproduct of a process whereby waste plant materials such as corn stalks and wood chips are heated to extract oils. When biochar, which is essentially charcoal, is added to farmland it has been found to improve soil properties for crop growth. However, there is concern that biochar additions to soil could also stimulate the production of greenhouse gases by soil bacteria. This study looked at how biochars produced from 6 different heating process/plant material combinations influenced the greenhouse gas emissions (carbon dioxide and nitrous oxide) in 2 different soils. It was found that 5 of the biochars significantly reduced N2O emissions from the silt loam soil, but only two biochars consistently reduced N2O emissions from the loam soil. Also, none of the biochar amendments affected CO2 emissions from the silt loam soil, whereas four of six biochars reduced CO2 emissions from the loam soil. Thus, overall, biochar addition to soils may actually reduce greenhouse gas emissions. This information will be useful to scientists and policy makers concerned with how agricultural practices affect greenhouse gas emissions.

Technical Abstract: Both soil and biochar properties have been shown to influence greenhouse gas emissions from biochar-amended soils, but the underlying mechanisms are poorly understood. Here we examine the effect of six lignocellulosic biochars produced from the pyrolysis of corn stover and wood feedstocks on CO2 and N2O emissions from two different soils. One hundred forty days following fertilization, none of the biochar amendments affected CO2 emissions from the silt loam soil, whereas four of six biochars reduced CO2 emissions from the loam soil: evidence of soil and biochar-specific negative priming. Five biochars significantly reduced N2O emissions from the silt loam soil, but only two biochars consistently reduced N2O emissions from the loam soil. The magnitude of N2O emissions suppression varied with respect to both biochar and soil type. Biochar amendments decreased final soil NO3- concentrations, and significantly affected final NH4+, suggesting that suppression of N2O emissions may be tied to biochar’s influence on soil NH4+ or NO3- concentrations, but more research is needed to confirm this mechanism. Overall, results suggest that select biochars may be paired with specific soils to reduce soil CO2 and/or N2O emissions.