|LOWER, BRIAN - The Ohio State University|
|DICK, RICHARD - The Ohio State University|
Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2020
Publication Date: 8/1/2020
Citation: Perez-Guzman, L., Lower, B.H., Dick, R.P. 2020. Corn and hardwood biochars affected soil microbial community and enzyme activities. Agrosystems, Geosciences & Environment. 3:e20082. https://doi.org/10.1002/agg2.20082.
Interpretive Summary: Biochar is charcoal material that has gained interest because it can improve soil quality. Although it can improve soil pH and water infiltration, its effect on soil microbes is not well understood as studies have shown contrasting trends in microbial abundance and activity after its incorporation into soil. This is of concern because soil microbes play important roles in nutrient cycling needed for plant growth and overall soil health. Our goal was to determine the effects of two different biochars in microbial abundance and activity in an agricultural soil during a 120-day incubation study. While biochar type did not affect fungal communities, it caused changes in the abundance of bacterial groups. Enzyme activities measured showed that the overall microbial activity was not affected, however, the enzyme involved in C cycling increased in soils with either biochar when compared to control. The results suggest that biochar can influence changes in microbial community composition and an enzyme activity influencing the carbon cycle in the agricultural soil evaluated.
Technical Abstract: Biochar has gained interest as a soil amendment to improve soil quality and as means to help mitigate climate change. With the recent focus given to the soil as a living system and the essential functions they provide, knowledge of different effects of biochar on the microbial component and soil types (chemical and physical properties) are critical. A laboratory incubation (120 days) study was conducted on a Bennington silt loam (fine, illitic, mesic Aeric Epiaqualf) amended with corn (CB) and hardwood (HB) biochars produced under slow pyrolysis. Biochars were analyzed for their chemical and physical properties, and were added to the soil on a carbon content basis without exceeding 2.5% w/w. Microbial community abundance and composition were evaluated by phospholipid fatty acids (PLFA) analysis, and potential enzyme activity by '-glucosidase, and fluorescein diacetate (FDA). There were no significant differences in the abundance of fungi (Saprophytic and AMF) or Gram-positive bacteria in samples incubated with biochars when compared to the control without biochar. However, soils incubated with corn biochar had higher abundance of Actinobacteria and Gram-negative bacteria, than hardwood biochar and control. The FDA activity did not show significant differences between soils incubated with biochar when compared to control. Conversely, the of B-glucosidase activity was significantly higher (p < 0.05) in soils incubated with either biochar than in control. These results suggest that biochar can influence changes in microbial community composition and an enzyme activity influencing cellulose degradation and soil organic matter (SOM) dynamics in the agricultural soil evaluated.