Abstract

ACOSTA OLAYA, Gladys Elena  and  RAMIREZ PISCO, Ramiro. Evaluation of the changes in the some physical and chemical properties of an ultisol for effect of the Bacillus subtilis. Rev. colomb. biotecnol [online]. 2010, vol.12, n.2, pp.203-213. ISSN 0123-3475.

The interest about the studies of bioremediation in deteriorated soils under and over exploitation, indiscriminate use of agrochemicals that alter the microflora, the self regulation system and the sustainability in the long term. An Ultisol, with poor chemical properties and low fertility, because the reduction of aggregates size (< 2.0 mm). Solarize to reduce the microbiological population, it was inoculated with the bacteria Bacillus subtilis in concentrations of 10⁶, 10⁷, 10⁸, 10⁹ colony forming units (cfu). In 120 days important increment in magnitude of: structural stability, size average of aggregates, pH, available phosphorus. Also diminish the interchangeable aluminum. These variations in the answer were related with the activity of the microorganisms in the soil, and it responds so that solubilisation capacity of minerals because the bacteria activity, production of alkaline conditions and biofilms too. Furthermore the increase of plant roots biomass, mucilages and carbohydrates cooperate in the formation of stable aggregates and bigger size of them. The physical and chemical properties at the end of the experiment were stabilized in bigger values than found in the initial soil. Confirming a positive general effect overall the soil, since the point of view of the global fertility, when increasing the available phosphorus, reduce the interchangeable acidity and increase the soil stability and average size aggregates in the short term.

Keywords : Calcified bacteria; biofilms; aggregate size.

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