Dynamics of the subsoil regeneration in degraded areas of Cerrado

The objective of this research was to evaluate the physical and chemical conditions of revegetated subsoil in degraded areas in a Cerrado biome and to verify which plants promote better conditions for soil recovery. The research was conducted in the remaining area of the hydroelectrical plant site at Ilha Solteira (SP). The experimental design was a completely randomized with five treatments and three replications. The treatments consisted of: natural regeneration area, brachiaria area, Pinus sp. area, exposed soil area and Cerrado grassland (used as control). The following soil characteristics were appraised: porosity; density, stability of aggregates, infiltration rate, temperature, exchangeable cations, organic matter, pH and potential acidity. The results show that Pinus is not a good species to recover the chemical attributes of the subsoil. The revegetated areas need to be improved in their physical attributes to allow a better development of the vegetation. Brachiaria and the natural regeneration were the most promising treatments, presenting results similar to natural Cerrado

Growth of Hymenaea stigonocarpa as a function of the addition of residues in degraded soil

ABSTRACT In areas where soil surface horizons were removed, the main edaphic problems are reduced amounts of organic matter and nutrients. Revegetation, especially with native species, has been indicated to recover these areas. Under this perspective, the present research has been developed to evaluate the contribution of organic and agro-industrial residues, as conditioners of soil fertility and their effects on initial growth of 'Jatobá-do-cerrado' seedlings. The treatments consisted of 4 agro-industrial residue doses (0, 15, 30 and 45 Mg ha-1) and 4 organic residue doses (0, 8, 16 and 32 Mg ha-1), with 16 treatments and 10 replicates. After 8 months of development, the soil was evaluated for phosphorus, organic matter, hydrogen potential, potassium, calcium, magnesium, potential acidity, aluminum and sum of bases, and plants were evaluated for leaf chlorophyll, height, collar diameter, fresh and dry matter of shoots and roots, and root length. The addition of residues to the degraded soil increased the fertility by raising calcium and magnesium levels. Agro-industrial residues contributed to increasing height, shoot dry matter and chlorophyll of H. stigonocarpa, while organic residues improved shoot fresh matter and chlorophyll