Biomassa microbiana e estoques de C e N do solo em diferentes sistemas de manejo, no Cerrado do Estado do Piau赤 = Microbial biomass and C and N stocks in soil under different management systems in the ＆Cerrado＊ of Piau赤 State

作者：Maria da Conceio Bezerra da Silva Matias; Adeodato Ari Cavalcante Salviano; Luiz Fernando de Carvalho Leite; Ademir Sergio Ferreira de Araujo

来源：Acta Scientiarum - Agronomy, 2009.

• plantio direto
• biomassa microbiana
• respira o basal
• no-tillage
• microbial biomass
• basal respiration

O objetivo do trabalho foi verificar os efeitos de diferentes sistemas de manejo sobre a biomassa microbiana e os estoques totais de carbono organico e nitrog那nio em um Latossolo Amarelo. Os sistemas de manejos avaliados foram: plantio direto (PD), preparo convencional (PC), al谷m de uma 芍rea rec谷m-desmatada (ARD) e uma com vegeta o nativa (AVN). As amostras de solo foram coletadas nas profundidades de 0-5, 5-10 e 10-20 cm. Nessas amostras, foram determinados os teores e estoques totais de C e N, a respira o basal, o carbono da biomassa microbiana (Cmic) e os quocientes microbiano (Cmic/COT)e metab車lico (qCO2). A 芍rea sob plantio direto apresentou maiores teores de C e N, al谷m de estoques de C na superf赤cie do solo. Para os estoques de N, n o houve diferen as entre as 芍reas avaliadas, em todas as profundidades. Os teores de carbono da biomassa microbiana(Cmic), observados no solo sob sistema PD, foram superiores aos observados no PC e ARD, em todas as profundidades. A ado o do sistema PD proporciona aumento na biomassa microbiana, C organico, N total e estoques de C do solo, indicando melhoria na qualidade do solo. The aim of this study was to verify the effects of different soil tillage systems on microbial biomass and the total organicC and N stocks in an Oxisol. The soil tillage systems evaluated were: no-tillage (PD) and conventional tillage (PC). A deforested area (ARD) and another with native vegetation (AVN) were used as references. The soil samples were collected in the 0-5, 5-10 and 10-20cm depths, and in these soil samples were quantified the contents and total stocks of C and N, basal respiration, microbial biomass C (Cmic), and microbial (Cmic/COT) and metabolic (qCO2) quotients. The values of microbial biomass C (Cmic) in the soil under PD were higher than those observed in PC and ARD in all depths. The area under notillage (PD) showed larger contents of C and N, and stocks of C on the surface of the soil. For the stocks of N, there were no differences among the evaluated areas, in all depths. Notillageadoption provides an increase in the soil microbial biomass and total C and N stocks, indicating improvement in soil quality.