Enzymatic activity of soil under organic and conventional management in the culture of sugar cane in Goiás ; Atividade enzimática do solo sob sistema de produção orgânica e convencional na cultura da cana-de-açúcar em Goiás

This work aimed to evaluate the activity of enzymes related with the carbon cycle, P mineralization and total enzymatic activity of soil cultivated with certified organic sugarcane with and without soil tillage, organic sugarcane under certification, conventional sugarcane with and without residue burning and a remaining area of Cerrado in Goiatuba, GO, Brazil. Soil samples were collected in March (summer) and in September (winter) 2009 from 0-10 cm depth for analysis of organic matter, pH, P, granulometry, total enzymatic activity, ?-glucosidase and acid phosphatase. Data were subjected to descriptive and multivariate analyses. The certified organic management of sugarcane without soil tillage had higher levels of ?-glucosidase activity, indicating increased cycling of organic matter in relation to other systems. The highest values of acid phosphatase were observed in the samples collected from the remaining area of Cerrado in the summer, followed by the certified organic management without soil tillage. Lower total enzymatic activity was observed in the management involving residue burning before the crop harvest. The remaining soil of Cerrado, followed by the certified area with organic management of sugarcane without soil tillage presented the best indicators of soil quality. ; Objetivou-se avaliar a atividade das enzimas ligadas ao ciclo do carbono, à mineralização do fósforo e atividade enzimática total do solo cultivado com cana-de-açúcar orgânica certificada com e sem revolvimento do solo, orgânica em certificação, convencional com e sem queima da palhada e uma área remanescente de Cerrado no município de Goiatuba, GO, Brasil. Foi realizada coleta de solo em março (período chuvoso) e setembro (período de estiagem) de 2009, na profundidade de 0-10 cm, para análises de matéria orgânica, pH, P, granulometria e atividade enzimática total, ?-glicosidase e fosfatase ácida. Os dados foram submetidos às análises descritiva e multivariada. O sistema de produção orgânico certificado de cana-de-açúcar sem ...