title: Biochar increased water holding capacity but accelerated organic carbon leaching from a sloping farmland soil in China.
abstract: A hydrologically contained field study, to assess biochar (produced from mixed crop straws) influence upon soil hydraulic properties and dissolved organic carbon (DOC) leaching, was conducted on a loamy soil (entisol). The soil, noted for its low plant-available water and low soil organic matter, is the most important arable soil type in the upper reaches of the Yangtze River catchment, China. Pore size distribution characterization (by N2 adsorption, mercury intrusion, and water retention) showed that the biochar had a tri-modal pore size distribution. This included pores with diameters in the range of 0.1-10 μm that can retain plant-available water. Comparison of soil water retention curves between the control (0) and the biochar plots (16 t ha(-1) on dry weight basis) demonstrated biochar amendment to increase soil water holding capacity. However, significant increases in DOC concentration of soil pore water in both the plough layer and the undisturbed subsoil layer were observed in the biochar-amended plots. An increased loss of DOC relative to the control was observed upon rainfall events. Measurements of excitation-emission matrix (EEM) fluorescence indicated the DOC increment originated primarily from the organic carbon pool in the soil that became more soluble following biochar incorporation.
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China.
authors.forename: Honglan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China. xytang@imde.ac.cn.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Tang
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Guan
authors.affiliation: School of Environmental Science, University of East Anglia, Norwich, England, UK.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Reid
authors.affiliation: Korea Biochar Research Center and Department of Biological Environment, Kangwon National University, Chuncheon, Republic of Korea.
authors.forename: Anushka Upamali
authors.initials: AU
authors.lastname: Rajapaksha
authors.affiliation: Korea Biochar Research Center and Department of Biological Environment, Kangwon National University, Chuncheon, Republic of Korea.
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Ok
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu, China. sunhuifiles@gmail.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Sun
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D002606:Charcoal; D002681:China; D060587:Groundwater; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; C540010:biochar; D002606:Charcoal; D002244:Carbon
keywords: Biochar; DOC; EEM fluorescence; Pore size distribution; Soil; Water holding capacity