title: The effect of biochar and its interaction with the earthworm Pontoscolex corethrurus on soil microbial community structure in tropical soils.
abstract: Biochar effects on soil microbial abundance and community structure are keys for understanding the biogeochemical cycling of nutrients and organic matter turnover, but are poorly understood, in particular in tropical areas. We conducted a greenhouse experiment in which we added biochars produced from four different feedstocks [sewage sludge (B1), deinking sewage sludge (B2), Miscanthus (B3) and pine wood (B4)] at a rate of 3% (w/w) to two tropical soils (an Acrisol and a Ferralsol) planted with proso millet (Panicum milliaceum L.). The interactive effect of the addition of earthworms was also addressed. For this purpose we utilized soil samples from pots with or without the earthworm Pontoscolex corethrurus, which is a ubiquitous earthworm in tropical soils. Phospholipid fatty acid (PLFA) measurements showed that biochar type, soil type and the presence of earthworms significantly affected soil microbial community size and structure. In general, biochar addition affected fungal but not bacterial populations. Overall, biochars rich in ash (B1 and B2) resulted in a marked increase in the fungi to bacteria ratio, while this ratio was unaltered after addition of biochars with a high fixed carbon content (B3 and B4). Our study remarked the contrasting effect that both, biochar prepared from different materials and macrofauna, can have on soil microbial community. Such changes might end up with ecosystem-level effects.
authors.affiliation: School of Civil, Environmental and Chemical Engineering, RMIT University, Melbourne, Australia.
authors.forename: Jorge
authors.initials: J
authors.lastname: Paz-Ferreiro
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Chenfei
authors.initials: C
authors.lastname: Liang
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Shenglei
authors.initials: S
authors.lastname: Fu
authors.affiliation: Departamento de Ingeniería Geológica y Minera, ETSI Minas, Universidad Politécnica de Madrid, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Mendez
authors.affiliation: Departamento de Producción Agraria, ETSI Agrónomos, Universidad Politécnica de Madrid, Madrid, Spain.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gasco
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D002244:Carbon / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry / Q000494:pharmacology*; D017753:Ecosystem; D005227:Fatty Acids / Q000032:analysis; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D059013:Microbial Consortia / Q000187:drug effects* / Q000502:physiology; D009835:Oligochaeta / Q000187:drug effects* / Q000502:physiology; D008897:Panicum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D005227:Fatty Acids; D010743:Phospholipids; D012722:Sewage; D012987:Soil; C540010:biochar; D002606:Charcoal; D002244:Carbon