Efecto del Herbicida Atrazina sobre la Población de Bacterias en un Suelo del Municipio de Saldaña, Tolima

Abstract

The effect of atrazine inthe populstions dynamics of soil microorgsnism in Saldaña, Tolima was evaluated. The soil microorganism studied were bacteria in general, phosphatesolubilizing bacteria, desnitrificant, aminificants, nitrobacte and nitrosomonas. We used a completely randomnized design with five treatments and four repetitions. Results were analyzed using Analysis of variance Treatments consisted of (1) original soil, (2) sterilized soil, (3) soil with substrate of corn stubble, (4) soil treated with 1.5 kg i.a. atrazine/ha, (5) soil with substrate of corn stubble and atrazine. The null hypothesis has consisted that there are not significant differences between population. Differences in variance were compared to F distribution of 5% significance level. The Turkey's test was also used, with the same significance level. Results showed that, as time goes on, the atrazine herbicide has a detrimental effect on the amonificant bacteria populations, as well as on nitrosomonas, desnitrificant and nitrobacter populations. However , ther corn stubble substrate with atrazine has reduced the effect by increasing the number of colony-forming units per gram of soil (U.F.C./g of soil).