Effects of Alkaline Pretreatments on Chemical Composition of Sugarcane Bagasse for Easy Degradation in Soil

To use sugarcane bagasse to improve the organic matter content of soils in arid and semiarid regions of Iran, an experiment was conducted to investigate the effect of alkaline pretreatment on chemical composition of sugarcane bagasse with different size of pieces and rate of its degradation in soil. Three different concentrations (0.5, 1 and 3 % w/v) of NaOH and KOH were used. The removal of lignin and hemicellulose in both alkaline pretreatments was affected by size of pieces of bagasse. The larger pieces of bagasse removed less lignin and hemicellulose. The pretreatment of sugarcane bagasse by different concentration of NaOH and KOH resulted in a depletion of lignin and hemicellulose and an increase in cellulose content. Also, increasing alkaline concentration increased the removal of hemicellulose and lignin in pretreated bagasse. Addition of pretreated bagasse in soil resulted in an increase of 1.37-2.23 times of soil respiration, as compared to non-pretreatment bagasse. Furthermore, removal of hemicellulose and lignin in pretreated bagasse, as barriers of decomposition, by NaOH and KOH provides favorable conditions for degradation of sugarcane bagasse in soil.