Analyzing the impacts of three types of biochar on soil carbon fractions and physiochemical properties in a corn-soybean rotation

Authors: SANDHU, SAROOP - South Dakota State University; USSIRI, DAVID - South Dakota State University; KUMAR, SANDEEP - South Dakota State University; CHINTALA, RAJESH - Innovation Center For Us Dairy; Schneider, Sharon; MALO, DOUGLAS - South Dakota State University; SCHUMACHER, THOMAS - South Dakota State University

Submitted to: Chemosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/29/2017
Publication Date: 6/12/2017
Citation: Sandhu, S., Ussiri, D.A., Kumar, S., Chintala, R., Papiernik, S.K., Malo, D.D., Schumacher, T. 2017. Analyzing the impacts of three types of biochar on soil carbon fractions and physiochemical properties in a corn-soybean rotation. Chemosphere. 184:473-481. doi: 10.1016/j.chemosphere.2017.05.165.

Interpretive Summary: Biochar is a by-product of the incomplete pyrolysis of organic materials for bioenergy production. There is interest in using biochar to improve the productivity of degraded soils. However, the effects of biochar application to soil are not well-tested under field conditions. We used field studies to evaluate the influence of biochar on soil physical properties and carbon and nitrogen fractions. We evaluated two soil types, one located in an eroded landscape position and the other in a position in which soil is deposited by erosion. The land was cropped to a corn-soybean rotation. Results showed that biochar treatments significantly increased the pH of soil at the eroded landscape. Biochar treatments had mixed effects on labile carbon and nitrogen fractions in surface soil, depending on biochar type and soil type. Overall, results showed that certain biochars applied at 10 Mg ha-1 to 0-7.5 cm depth of soil can increase the pH and labile C fraction of sandy loam soil. However, long-term monitoring is needed to quantify the benefits of biochar application under field conditions. Additional field studies are recommended to evaluate changes in soil physical and chemical properties at higher rates of biochar application and under different environmental conditions. Scientists and land managers can use these results to evaluate whether soil amendment with biochar may be useful to improve soil productivity.

Technical Abstract: Biochar is a soil amendment produced from incomplete pyrolysis of organic materials in the absence of oxygen. In most previous studies, the impacts of biochar on soil physical properties and organic carbon was investigated under controlled conditions such as laboratory or greenhouse environments. Therefore, the objective of this study was to use field studies to evaluate the influence of biochar on soil physical properties and carbon and nitrogen fractions for two selected soil types under a corn (Zea mays L.)-soybean (Glycine max L.) rotation. The three plant based biochar materials used for this study were produced from C optimized gasification of corn stover, ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.). The three biochar types were applied to a Maddock (sandy, mixed frigid Entic Hapludolls) and Brookings (fine-silty, mixed, superactive Pachic Hapludolls) soil located at eroded (shoulder) and depositional (footslope) landscape positions respectively. Data showed that biochar treatments significantly increased the pH of soil at the eroded landscape. Biochar treatments had mixed effects on labile C and N fractions for the 0-7.5 cm depth, depending on biochar type and soil type. Overall, results showed that certain biochars applied at 10 Mg ha-1 to 0-7.5 cm depth of soil can increase the pH and labile C fraction of sandy loam soil. However, long-term monitoring is needed to quantify the benefits of biochar application under field conditions. Additional field studies are recommended to evaluate changes in soil physical and chemical properties at higher rates of biochar application and under different environmental conditions.