Abstract

The aquatic macrophytes removed from hydroelectric power plants, as well as boiler ash derived from burning sugarcane bagasse can provide nutrients and recover degraded soils more quickly. Thus, this study aimed to evaluate the chemical attributes of a degraded soil in recovery process with mechanical preparation, with or without addition of organic residue (aquatic macrophytes) or agroindustrial residue (ash from sugarcane bagasse), compared to a degraded area without interference  in the time of soil removal and in a conserved Cerrado area. The experimental design was a randomized block with four replications. The treatments were: conserved Cerrado soil (T1), area of degraded soil without human intervention since their degradation (T2), soil with mechanized preparation without addition of residue (T3), soil with mechanized preparation and addition of 32 Mg ha^-1 of organic residue (T4), soil with mechanical preparation and addition of 45 Mg ha^-1 of agroindustrial residue (T5). The orthogonal contrasts analyzed were C1 [(T2+T3+T4+T5)/4 -T1], C2 [(T2+T3) - (T4+T5)], C3 [(T2) -(T3)] and C4 [(T4) - (T5)]. In general, the chemical attributes of degraded soil increased after the incorporation of organic and agroindustrial residue, which is higher than the soil of the conserved Cerrado area. The boiler ash contributed most, to increase the nutrient content and fertility of the degraded soil.

Key words: Aquatic macrophytes, ash from sugarcane bagasse, degraded soil, fertility, soil tillage.