Effects of ground basalt and organic residues on the chemical and microbiological aspects on bare subsoil and on the growth of Astronium fraxinifolium Schott

Abstract

Degraded areas such as the originated from the construction of the Hydroelectric Plant of Ilha Solteira, where the former top soil was removed, present a naturally low regeneration and bare subsoil, with compaction problems, high global density, high resistance to root penetration and lack in organic matter. In order to recover such areas it is of paramount importance to improve general subsoil conditions. The objective of this research was to verify the effects of ground basalt ('rochagem') and application of different organic residues on the chemical and microbiological aspects of a bare subsoil, and on the growth of 'Goncalo Alves' (Astronium fraxinifolium Schott), a native cerrado plant. The experiment was conducted under greenhouse conditions, with 17 treatments: subsoil of a degraded area with four levels of basalt (0, 2, 4 and 8 t ha -1 ), combined or not with 8 t ha -1 of three organic residues (water hyacinth, manure and domestic sewage), resulting in