title: Biochar affects soil organic matter cycling and microbial functions but does not alter microbial community structure in a paddy soil.
abstract: The application of biochar (BC) in conjunction with mineral fertilizers is one of the most promising management practices recommended to improve soil quality. However, the interactive mechanisms of BC and mineral fertilizer addition affecting microbial communities and functions associated with soil organic matter (SOM) cycling are poorly understood. We investigated the SOM in physical and chemical fractions, microbial community structure (using phospholipid fatty acid analysis, PLFA) and functions (by analyzing enzymes involved in C and N cycling and Biolog) in a 6-year field experiment with BC and NPK amendment. BC application increased total soil C and particulate organic C for 47.4-50.4% and 63.7-74.6%, respectively. The effects of BC on the microbial community and C-cycling enzymes were dependent on fertilization. Addition of BC alone did not change the microbial community compared with the control, but altered the microbial community structure in conjunction with NPK fertilization. SOM fractions accounted for 55% of the variance in the PLFA-related microbial community structure. The particulate organic N explained the largest variation in the microbial community structure. Microbial metabolic activity strongly increased after BC addition, particularly the utilization of amino acids and amines due to an increase in the activity of proteolytic (l-leucine aminopeptidase) enzymes. These results indicate that microorganisms start to mine N from the SOM to compensate for high C:N ratios after BC application, which consequently accelerate cycling of stable N. Concluding, BC in combination with NPK fertilizer application strongly affected microbial community composition and functions, which consequently influenced SOM cycling.
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), 100101 Beijing, China. Electronic address: tianj@igsnrr.ac.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), 100101 Beijing, China.
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077 Göttingen, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Dippold
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), 100101 Beijing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077 Göttingen, Germany; Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, 142290 Pushchino, Russia. Electronic address: janeblag@mail.ru.
authors.forename: Evgenia
authors.initials: E
authors.lastname: Blagodatskaya
authors.affiliation: Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077 Göttingen, Germany; Department of Agricultural Soil Science, University of Göttingen, 37077 Göttingen, Germany.
authors.forename: Yakov
authors.initials: Y
authors.lastname: Kuzyakov
mesh_terms: D002606:Charcoal; D055669:Ecological and Environmental Phenomena; D017753:Ecosystem; D004784:Environmental Monitoring; D005308:Fertilizers; D009584:Nitrogen; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D005308:Fertilizers; D012987:Soil; C540010:biochar; D002606:Charcoal; D009584:Nitrogen
keywords: Biochar; Enzymes; Microbial community; Microbial function; Soil organic matter fraction