|Lentz, Rodrick - Rick|
|JOHNSON, MARK - Environmental Protection Agency (EPA)|
Submitted to: BioEnergy Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/11/2016
Publication Date: 3/13/2016
Citation: Novak, J.M., Ippolito, J.A., Lentz, R.D., Spokas, K.A., Bolster, C.H., Sistani, K.R., Trippe, K.M., Phillips, C.L., Johnson, M.G. 2016. Soil health, crop productivity, microbial transport, and mine spoil response to biochars. BioEnergy Research. 9(2):454-464.
Interpretive Summary: Over the past 10-20 years, United States Department of Agriculture-Agricultural Research Service (USDA-ARS) scientists have been evaluating biochars potential to improve degraded soil quality characteristics with anticipation of increasing soil carbon (C) sequestration, improving plant growth conditions, obtaining higher crop yields, and attenuating microbial movement in soil. Our understanding of the positive and negative impacts of biochar performance on soil conditions and crop yields has been obtained through individual or collaborative multi-location experiments at the laboratory, greenhouse, and field scales. From these studies, ARS scientists have reported that the success of biochars as soil amendments for improving crop yields has been mixed. Some studies report that crop yields were improved after adding biochar to soil, while others report no change in crop yields. These mixed results prompted ARS scientists to theorize that biochars may be more effectively used if they are produced with chemical and physical characteristics that target specific soil health deficiencies. Biochars have demonstrated an emerging capability for remediation of mine impacted soils. Reclamation of mine spoils or mine-impacted soils is a complicated task, often involving intricate methods and multiple state and federal agencies. For example, USDA-ARS scientists have collaborated with Environmental Protection Agency (EPA) scientists to determine if biochars can be engineered to restore mine-impacted soils, to promote the ability of native plant cover to re-colonize mine-impacted soils, increase soil C stocks, stimulate microbial activity, and sequester heavy metals in-situ. From these experiments, it is anticipated that biochar management practices will be developed to reclaim vast areas of mine impacted soils and spoils as well as improve soil health characteristics in agricultural lands.
Technical Abstract: Biochar is being evaluated by scientists from the United States Department of Agriculture (USDA) Agricultural Research Service (ARS) for its potential to sequester soil C, to improve soil health, and to increase crop yields. ARS scientists from multiple locations such as Florence, SC, Kimberly, ID, Bowling Green, KY, Corvallis, OR, and St. Paul, MN, are conducting investigations with agronomic experiments at the laboratory, greenhouse, and field plot scales. To further expand biochars utility, ARS scientists have collaborated with United States Environmental Protection Agency (US EPA) investigators to reclaim mine-impacted soils. In the agronomic investigations, both positive and negative aspects of biochar application were revealed. In some experiments, biochars were reported to have no effect on crop yields, and minimal impact on movement of microbial pathogens through soil. In other experiments, biochars were reported to improve soil fertility, increase water retention, and bind with heavy metals in solutions and in mine spoil soils. This variation in biochars influence, substantiates and encourages further work on the designer biochar concept, which states that the biochars can be crafted for targeted agronomic and environmental purposes. There is a need to broadcast the successes and failures of biochar research reported by scientists from both agencies. Consequently, the objectives of this review are: to report on biochar effectiveness as a soil amendment; to ascertain its ability to modify soil properties, to evaluate its impact on soil leaching of microbes; and its potential capacity to help reclaim mine spoil sites.