Resumo

GABBARINI, Luciano Andrés; FRENE, Juan Pablo  e  WALL, Luis Gabriel. Efecto de la rotación de cultivos en siembra directa sobre la actividad fosfatasa del suelo. Cienc. suelo [online]. 2017, vol.35, n.2, pp.229-238. ISSN 1850-2067.

The aim of this work was to investigate the effects of different no-till agricultural managements related to crop rotation over soil phosphatase kinetics parameters, V_max and K_m, using grassland soils as references. Treatments were replicated sampling during summer and winter in four productive fields at different locations along a 400 km east-west transect in the central Argentinean Pampas, through successive cropping cycles within two years. The quantity of soil phosphatase estimated as V_max show significant differences between agricultural practices. Opposite seasonal dynamics of phosphatase activities were found between grassland soils and monocropping agricultural soils while crop rotated. Soils dynamics were more similar to grassland than to monocropping ones. Regardless of the location and treatment, K_m values did not show differences, but clearly show a seasonal response. A positive correlation was found between phosphatase activities and microbial biomass, but microbial biomass could not fully explain V_max values since an estimation of specific activity on the basis of microbial biomass still show the differences between treatments.

Palavras-chave : Monocroping; MIcrobial biomass; Enzymes.

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