Impactos do uso das queimadas em diferentes sistemas de manejo no sertão paraibano.

Abstract

The burning of pasture and vegetable waste in the run-up to the rains in semi-arid region is a practice usually applied by farmers to facilitate cleaning the área and renew pasture. The present study aimed to evaluate the effect of are on chemical and biological characteristics of soil in different áreas in paraibano. The treatments consisted in the use of are in pasture and com cultivation área and not the use of are in grassland and savanna preserved área that served as a witness. Samples were hem bi-monthly, September/2008 to July 2009. Soil samples were collected at a depth of 0-20 cm in each área, for analyses of chemical indicators. For the determination of biological indicators were installed trapo like "Provid" which consisted in the use of pet bottles, for collecting of macrobenthos from soil samples indeformadas for determination of mesofauna were extracted using type pullers Berlese-Tullgren modified (OLIVEIRA, 1 999). Composed of rectangular tablets, each containing structure, 25W bulbs, divided into two top compartment contains the rings with the samples and lamps, while the lower deck are funnels and the glass jars with the solution of the ethyl alcohol of 80% for the collapsing of the bodies. The largest number of individuais of mesofauna was collected in the áreas of the caatinga preserved and native pasture without burning. Already for the capturing of macrobenthos organisms was superior in the área of native pasture without burning. The pH values analyzed was dose to neutrality, suffering greater reductions mainly on QCC. In the áreas burned (PNQ and CC\A/) saw an increase in leveis of P and K after burning and then reduction in leveis occurred.