Microbial activity and decomposition of different organic residues in soil under field conditions and water stress simulated

This study evaluated the microbial activity and dynamics of manure decomposition in cerrado soil under simulated water stress conditions and natural water regime in the field. In laboratory the soil of degraded pasture was placed in polyethylene pots (0.2 m profile), sealed with plastic bags. The treatments was constituted of bovine manure (0.25 kg), poultry (0.1 kg), bovine + poultry (0.175 kg) and a control and in the field same treatments were used with equivalent dosages per square meter and incorporated into 0.2 m. The experimental design was randomized with six replications. We evaluated the emission of CO2 by titration method using 20 ml of NaOH (0.5 M) in the pots in laboratory and NaOH (2 M) inside of campanula in field, quantifying the CO2 emitted to the 1, 3, 6, 10 and 25 days in the laboratory and at 8, 10, 13, 17 and 32 days in the field. Under simulate water stress the addition of the treatments had a positive effect on microbial activity. Under natural hydrological regime the microbial activity reaches its peak soon after the first rains of the wet season with the EA treatment towering over other sources.