Biological activity of soils cultivated with topinambur inoculated with Azospirillum Brasilense and micorrícic fungi.

Abstract

Soil samples were collected in the province of Catamarca in lots grown with topinambur (Helianthus tuberosus L.) at the time of implantation and harvest during four agricultural cycles. The tubers were treated with Azospirillum brasilense, mycorrhizal fungi or both microorganisms. Tubers corresponding to the controls were not inoculated with these microorganisms. Total Biological Activity (ABT) was determined by Fluorescein Diacetate Hydrolysis to the collected samples. The ABT of the soil was affected by the different treatments of the crop. Microbial inoculation raised the ABT of the studied soils, differing statistically with the controls. Signifi cant differences were also observed between the ABT of the soils at the beginning of the crop with the values recorded at their harvest. The inoculation of topinambur tubers with A. brasilense and mycorrhizal fungi affects the ABT of cultivated soils.