soil microbial activity in conventional and organic agricultural systems土壤微生物活动在传统和有机农业系统.pdf

Sustainability 2009, 1, 268-276; doi:10.3390/su1020268 OPEN ACCESS sustainability ISSN 2071-1050 /journal/sustainability Article Soil Microbial Activity in Conventional and Organic Agricultural Systems Ademir S.F. Araújo 1,*, Luiz F.C. Leite 2, Valdinar B. Santos 3 and Romero F.V. Carneiro 1 1 Laboratório de Qualidade do Solo, Universidade Federal do Piauí, Centro de Ciências Agrárias, Teresina, PI, 64000-000, Brazil; E-Mail: romero@ufpi.br 2 Embrapa Meio Norte, Av. Duque de Caxias, SN, Teresina, PI, 64000-000, Brazil; E-Mail: luizf@cpamn.embrapa.br 3 Universidade Estadual do Piauí, Av. Nossa Senhora de Fátima, Parnaíba, PI, 64202-220, Brazil; E-Mail: santosvb@.br * Author to whom correspondence should be addressed; E-Mail: asfaruaj@.br; Tel.: +55-3215-5740; Fax: +55-3215-5743 Received: 9 April 2009 / Accepted: 31 May 2009 / Published: 4 June 2009 Abstract: The aim of this study was to evaluate microbial activity in soils under conventional and organic agricultural system management regimes. Soil samples were collected from plots under conventional management (CNV), organic management (ORG) and native vegetation (AVN). Soil microbial activity and biomass was significantly greater in ORG compared with CNV. Soil bulk density decreased three years after adoption of organic system. Soil organic carbon (SOC) was higher in the ORG than in the CNV.