Universitas Scientiarum (Dec 2011)
Influencia de la materia orgánica y Azotobacter nigricans en un cultivo de Stevia rebaudiana B
Abstract
Influence of organic matter and Azotobacter nigricans on a Stevia rebaudiana B. plantation Stevia rebaudiana is a plant thataccumulates a non-caloric sweetener compound known as stevioside. This crop is traditionally fertilized with chemicals that areharmful for the ecosystem, forcing to find organic alternatives to mitigate this damage. Objective. To study the effect of organic matterand an Azotobacter nigricans-based bio-fertilizer on a Stevia rebaudiana plantation grown in acidic soil in the Department of Meta,Colombia. Materials and methods. Five treatments were established: T1 and T2 with the application of home organic waste compostat concentrations of 15 and 30 ton ha-1. T3 and T4 with the same compost concentrations and inoculating the A. nigricans bio-fertilizer.T5 contained the bio-fertilizer alone. The control consisted of the application of the Bokashi compost under the usual conditions ofcultivation. Plant growth was assessed by biomass increase measured as dry weight, production, and leaf area. The physicochemicalanalysis of soil included: percentage of organic carbon, water content, and pH. Results. The inoculation of the bio-fertilizer produced an increase in the rate of mineralization of compost, reaching a final 4.85% of OC between 90 and 180 days after inoculation. There were significant (p< 0.05) differences between biomass production with T2 (1,538 kg ha-1) and the control (477 kg ha-1). Regarding the soluble solid content, T1, T3 and T4 showed the highest °Brix values (12.4, 12.35 and 12.15, respectively). Conclusions. The concentration of 30 ton ha-1 produced the highest biomass production and the application of the biofertilizer showed a positive correlation with compost mineralization and glucoside synthesis.
