A field decomposition and release of nutrients from trash of sugar cane mechanically harvested and without previous detrashing through burning was evaluated. During the experimental period -- August 1996 through August 1997 -- rainfall was 1,733 mm and mean maximum and minimum temperatures were 28.0 and 18.0ºC, respectively. After one year the mass of trash remained on field decreased of approximately 20%, mostly derived from the decarboxylation of the cell content and hemicelulose. Among all structural carbohydrates only the hemicelulose decomposed. The percentage of K, Ca and Mg released in relation to the total nutrient content in original trash was 85, 44 and 39%, respectively. The N mineralization of the trash was not significant (18%) thus resulting in a negligible statistical difference among the N contents in original and remaining trash
