It was studied the aggregate stability of an oxisol maintained with vegetation of native forest; annual crops for 20 years; a citrus orchard mantained during 9 years with permanent ground cover of Arachis prostrata Bong. Ex Benth.; or permanent spontaneous vegetation (mainly gramineous) controlled by mowing (3-4 times in the rain period of rains) and tillage (once a year in the dry period); or bare soil maintained by manual weeding. The aggregate stability was determined in samples submitted or not to treatment to remove hot water soluble organic matter. The forest vegetation provided larger stability followed by the orchard submitted to the permanent covering with leguminous or gramineous plants. Extraction of hot-water soluble carbon did not cause significant differences in aggregate stability, although there has been a significant correlation between hot water soluble carbon and soil aggregation.
soil aggregation; structure; carbon
