Field decomposition and release of sugar cane trash nutrients

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