A study was carried out to evaluate biomass decomposition of aquatic macrophytes incorporated or not into soil, due to mechanical control, at the Americana/SP UHE Reservoir. Analysis was performed in a greenhouse at the Weed Science Research Center (NUPAM), UNESP, Botucatu. Plastic vases containing 24 kg of soil were assessed by simulating discards of 50, 100, 150 and 200 t of fresh matter ha-1.The decomposition process was evaluated by CO2 release, divided into two stages: dry soil and wet soil. Quantification of released CO2 was performed through titration of solution added to vase incubation. Data were interpolated and analyzed by Mitscherlich model with some modifications. A quick CO2 release up to the 10th day was observed in the first stage (dry soil), followed by stabilization. The highest CO2 content released was observed in the 200 t MF ha-1 discard treatment incorporated into soil. Data assessed during the second stage (wet soil) showed a higher linearity in the CO2 release process, indicating a longer period of discarded biomass decomposition.
aquatic macrophytes; degradation; CO2 release
