title: Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study.
abstract: This study examined the effect of nitrogen (N) on biochar stability in relation to soil microbial community as well as biochar labile components using δ13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant) straw in absence (BC0) and presence (BCN) of N and monitored for dynamics of carbon dioxide (CO2) flux, phospholipid fatty acids (PLFAs) profile and dissolved organic carbon (DOC) content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05), and the proportions of decomposed biochar carbon (C) were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05) higher than DOC in biochar (1.75%) and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05) increased the proportion of gram-positive (G+) bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G-) bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Weixin
authors.initials: W
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
authors.forename: Huanjun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Land and Environment, AgResearch, Hamilton, New Zealand.
authors.forename: Jiafa
authors.initials: J
authors.lastname: Luo
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Adelaide, Australia.
authors.forename: Nanthi
authors.initials: N
authors.lastname: Bolan
mesh_terms: D000383:Agriculture; D002244:Carbon / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis*; D002606:Charcoal; D018556:Crops, Agricultural; D009584:Nitrogen / Q000032:analysis*; D012987:Soil; D012988:Soil Microbiology; D003313:Zea mays
chemical_list: D012987:Soil; C540010:biochar; D002245:Carbon Dioxide; D002606:Charcoal; D002244:Carbon; D009584:Nitrogen