Caracterização dos Argissolos amarelos com adição de resíduos de madeira: uma alternativa de uso como cobertura em solos da Amazônia paraense.

Abstract

In soils highly intemperic happens in the tropics, the reason of impoverishment is related to the lixiviation of the nutrients of the superficial layers. An alternative to minimize this loss of nutrients would be the use of organic coverings in these soils, be covering green or dead (mulch). In that sense, with the intention of characterizing the morphologic aspects, physical and chemical of the soils with and without addition of wood residues as covering, under the paricá (Schizolobium amazonicum) and pupunha culture (Bactris gasipaes). Were selected and collected 32 samples of 4 profiles of soil of the areas of paricá and pupunha planting with and without addition of wood residues for evaluation of their morphologic characteristics, physics and chemistries. The use of wood residues as covering favored for decrease of the density with values among 1,19 to 1,33 kg.dm-3 for the soils with addition of residues, while the soils without addition of wood residues the values were from 1,19 to 1,67 kg.dm-3. The same influence can be noticed for the increase of the porosity in the soils with material addition with values from 0,48 to 0,46 m3.m-3 in the superficial horizons, while the soils without residues, these demonstrated results from 0,35 to 0,38 m3.m-3. The pH values in water, for the soils with covering of wood residues varied from 4,6 to 6,0. To the soils without addition of wood residues, these presented values from 4,6 to 5,2. Could be verified that the addition of wood residues favored in the increase of the pH in the soil. The highest values for the saturation of bases were also observed for the soils with use of wood residues as covering, the values varied inside of these profiles, among 26 to 54%. While that for the profiles without addition of organic material presented variation among 26 to 39%. The appropriate use of wood residues in the soil played important part in the readiness of some nutritious as the calcium and the magnesium, reduced the acidity of the soils. Like this, the use of wood residues as covering in the soil in agroforests systems is satisfactory for allowing an appropriate destination for these materials besides improving the environmental conditions of the Amazon soils.