Conclusion
In this study, the biochars were by-products of bio-oil production from corn stover, switchgrass,
and Ponderosa pine wood residue using microwave pyrolysis unlike previously
published studies. The characteristics and reactivity of biochars with soil are highly heterogeneous
with batches of production using similar feedstock and pyrolytic conditions and the
findings of a study could not be applied universally to all biochar materials. In conclusion,
this incubation study demonstrated the effectiveness of biochars in ameliorating acidity
Archives of Agronomy and Soil Science 401
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which increased the soil pH, EC, and CEC and decreased the exchangeable acidity. Corn
stover biochar was found to have significantly better liming potential than switchgrass
biochar. The liming potential of biochar can be attributed to their alkalinity, proton
consumption capacity/acid neutralization capacity, and base cation concentration. The
incorporation of these highly carbonaceous biochar materials can induce ameliorating
changes to chemical properties of acidic soils and improve the bioavailability of plant
essential nutrients. Future research needs to evaluate the liming effect of biochars on acidic
soils and their practical management (timing and application methods) and economic
viability under field conditions. This type of studies at different locations with different
feedstocks and pyrolytic process will help to design biochar materials as liming amendments
for farmers to reclaim acidic soils with specific guidelines.
Acknowledgment
This project was supported by Agriculture and Food Research Initiative Competitive