CHANGES ON SOIL WETTABILITY,AGGRREGATE STABILITY AND ORGANIC MATTER CONTENT AFTER HEATING AND BURNED OF SUGARCANE RESIDUALS.

An experimental fire by using sugarcane residuals was conducted to study the effect of temperature on aggregate stability, water retention and organic matter content in soil samples from  surface layers in two cases, the first under laboratory conditions, where temperature up to 300 ⁰Ċ and heat can be controlled and the secand under field conditions to study the changes in some soil physical properties during 4 month after fire. The obtained results showed that, there is no variation in cohesive forces resulting from temperature treatment during the 4 month following the fire. Heating programs in laboratory simulation have been used to control inputs of heat and to measure the influence of temperature on soil properties. Burned of sugarcane residuals have no clear effect on soil properties under study except soil wettability, organic matter content which were increased in burned soil compared with control. In the thermal treatment, at 200 ⁰C Sb,(stability of soil aggregate pretreatment in  benzine), Se (stability of soil aggregate pretreatment in in alcohol) and Sw (stability of soil aggregate in water ),values are those of very stable aggregates. When the temperature raised to 300 ⁰C Sb  and (Se-Sb) were decreased. The dry meanweight diameter (DMWD) is reduced by heating when the temperature reached 200 ^oC and there is no detectable effect of heating on soil organic matter decrease until 200 ^oC.