Abstract

Change from the traditional harvesting system with burns to mechanized harvesting of sugarcane, as well as the amount of straw needed to remain in the field for sustainability of the production system and how much could be removed for sectors such as energy cogeneration and bioethanol production, are not clarified issues. The objective of this study was to evaluate the impact of harvest management with burning (traditional) and cultivatation with different amounts of straw on the industrial quality and productivity of sugarcane. The effect of six treatments were evaluated: cane burning, 0, 25, 50, 75 and100% (20 Mg ha^-1) of straw on the industrial quality (soluble solids (°Brix), Pol, apparent purity, total sugars (TS), reducing sugars (RS) and fiber) and productivity (Mg Pol ha^-1) of sugarcane. At the end of the cycle, the straw decomposition rate for each treatment was also verified. The higher the percentage of straw, the higher the degradation rate. The change of burned cane harvesting system for sugarcane under straw results in improved productivity of sugarcane and favors the production of sugar. The straw and harvest system change do not affect the industrial quality of sugarcane. The harvest with burning, the total withdrawal or of 75% of the straw of the field result in lower productivity. The maintenance of 50% of the straw on the soil surface is sufficient to improve the productivity of sugarcane in dry period, and the remaining 50% can be used for second generation of ethanol production or electricity without damaging the crop productivity.

Key words: Saccharum spp, soil cover technological quality, biomass, sucrose.