|MASIELLO, CAROLINE - Rice University|
|DUGAN, BRANDON - Rice University|
|BREWER, CATHERINE - Rice University|
|LIU, ZUOLIN - Rice University|
|SORRENTI, GIOVAMBATTISTA - University Of Bologna, Italy|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 6/11/2014
Publication Date: 4/15/2015
Citation: Masiello, C., Dugan, B., Brewer, C., Spokas, K., Novak, J., Liu, Z., Sorrenti, G. (2015) Biochar effects on soil hydrology. In: Lehmann, J., Joseph, S., editors. Biochar for Environmental Management Science, Technology and Implementation. 2nd Edition. London, UK: Routledge. p.541-560.
Technical Abstract: Biochar has the potential to alter soil hydrology, and these alterations may lead to significant changes in water cycling and ecosystem processes mediated by water. Biochar soil amendment may change infiltration and drainage in both sandy and clay soils, may increase or decrease plant-available water, may alter soil hydrophobicity, and may also result in long-term hydrologic changes from the integration of biochar carbon (C) into the soil organic matter pool. Because soil water is central to soil microbial processes, there may be ancillary soil microbial changes from altered soil water availability, including shifts in greenhouse gas production (CO2, N2O, and CH4), changes to soil fauna activity, nutrient availability or leaching of solutes. It is possible that these changes could be beneficial: one often-cited positive example would be a biochar-driven increase in plant-available water or in drought-stressed agricultural soils. Other potential positive outcomes could be biochar-driven improvements in soil water that facilitated ecosystem restoration in damaged environments, and another would be reduction in ecosystem CH4 and N2O production from improved soil drainage. However, as with biochar’s agronomic effects, there are likely scenarios where biochar’s hydrologic impacts are either neutral or negative. To implement biochar amendment effectively, we need a better understanding of the controls on biochar-driven changes in soil hydrology. Here we review what is known about the mechanisms that may allow biochar to change impact soil water properties, considering both short- and long-timescale processes through which biochar could act on soil water. We compare mechanisms to existing observations of biochar-driven hydrologic changes and we outline research needs. We also recommend best practices for monitoring soil hydrologic response to biochar amendment.