Effects of atrazine herbicide on the soil and its relation to chemical properties (edaphic and radical tissue) on a soil in Saldaña, Tolima

Abstract

We evaluated the effect of atrazine in the dynamics of microorganism populations of a soil in Saldana, Tolima. The groups of microorganisms studied were: Algae, Fungi in general, fungi arbuscular mycorrhizaformers, actinomycetes, Bacteria in general, bacteria that solubilizes phosphate, Denitrifying Bacteria , Amonifying Bacteria, Nitrobacter and Nitrosomones (The group of the before organism's was analyzed and named as mi crobial total population). We used a random design with five treatments and four repetitions. The results specifically showed that the atrazine herbicide caused a detrimental effect through the time on populations Amonifying Bacteria , nitrosomone Bact eria, Denitrifying Bacteria and nitrobact er Bacteria and Algae. However, the substrate (Corn bagasse) when added with atrazine attenuated the effect caused by the herbicide, increased the number of units colonies formers per gram of soil (U.F.C. / g. of soil). Although the mentioned increase was lesser than in the soil without treatment (Treatment T1 ) or original soil, except t he Amonifying Bacteria and Denitrifying Bacteria population, which in deed overcame this treatment. In the same way the soil close to the rhizosphere showed the similar increase effect of U.F.C. / g. of soil when adding substrate with atrazine, except the algae population. Likewise, the increase was. lesser compared to the soil without treatment (T1 ). Besides, we obtained that the substrate, when added, only increased the number of U.EC/g of soil than when added with the atrazine, except the Amonifying Bacteria and Denitrifying Bacteria populations which reported values of U.F.C. /g. of soil lower than t he obtained when substrate with atrazine was applied