Papers

Summary

In this work, it was determined the spatial variability structure of soil CO₂ emission, the temperature and the soil moisture in two locations currently cultivated with sugar cane and submitted to different management systems: slash/burn and no-till, in the northeast of São Paulo State. The soil CO₂ emission and the soil temperature were registered by using a portable chamber and a temperature sensor of LI-6400 system. Soil moisture was measured by a portable TDR system. The highest emission was observed in the slash and burn plot, with an average value of 2.05 μmol m^-2 s^-1, but spatial variability structure was observed just for the CO₂ emission under the no-till management systems. In the slash and burn system, the kriging maps of soil CO₂ emission, the temperature and the moisture shown to be related to the land declivity, as the higher emissions and temperatures were located in the highest level, and the smaller moisture values located in the lowest parts of the studied area. Results indicate a positive linear correlation between soil emission and temperature and also a negative correlation regarding soil moisture, for the slash and burn plot only, but not in the no-till plots, where crop residues were left in soil surface and certainly modified the direct incidence of the solar radiation and the action of rain drainage.