title: Impact of biochar amendment on soil water soluble carbon in the context of extreme hydrological events.
abstract: Biochar amendments to soil have been promoted as a low cost carbon (C) sequestration strategy as well as a way to increase nutrient retention and remediate contaminants. If biochar is to become part of a long-term management strategy, it is important to consider its positive and negative impacts, and their trade-offs, on soil organic matter (SOM) and soluble C under different hydrological conditions such as prolonged drought or frequent wet-dry cycles. A 52-week incubation experiment measuring the influence of biochar on soil water soluble C under different soil moisture conditions (wet, dry, or wet-dry cycles) indicated that, in general, dry and wet-dry cycles increased water soluble C, and biochar addition further increased release of water soluble C from native SOM. Biochar amendment appeared to increase transformation of native SOM to water soluble C, based on specific ultraviolet absorption (SUVA) and C stable isotope composition; however, the increased amount of water soluble C from native SOM is less than 1% of total biochar C. The impacts of biochar on water soluble C need to be carefully considered when applying biochar to agricultural soil.
authors.affiliation: Department of Land, Air and Water Resources, University of California, Davis, 95616, United States; College of Environmental Science & Engineering, Donghua University, Shanghai, 201620, China. Electronic address: dyuwang@ucdavis.edu.
authors.forename: Daoyuan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Land, Air and Water Resources, University of California, Davis, 95616, United States.
authors.forename: Deirdre E
authors.initials: DE
authors.lastname: Griffin
authors.affiliation: Department of Land, Air and Water Resources, University of California, Davis, 95616, United States.
authors.forename: Sanjai J
authors.initials: SJ
authors.lastname: Parikh
authors.affiliation: Department of Land, Air and Water Resources, University of California, Davis, 95616, United States.
authors.forename: Kate M
authors.initials: KM
authors.lastname: Scow
mesh_terms: D000383:Agriculture; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D055864:Droughts; D006812:Humic Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D062070:Hydrology; D012987:Soil / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry*
chemical_list: D006812:Humic Substances; D012987:Soil; C540010:biochar; D014867:Water; D002606:Charcoal; D002244:Carbon
keywords: Biochar; Drought; Water soluble C; Wet-dry cycles