AN ASSESSMENT OF THE INFLUENCE OF SELECTED HERBICIDES ON THE MICROBIAL PARAMETERS OF SOIL IN MAIZE (ZEA MAYS) CULTIVATION

Abstract

Application of herbicides inhibit development of weeds, but at the same time they can negatively influence soil microbial activity. The microbiological indicators allow estimating changes in soil contaminated with herbicides. The aim of the study was to assess the influence of selected postemergence herbicides: Stellar 210 SL + Olbras, Maister Power 42.5 OD, Laudis 44 OD, Collage 064 OD, Hector Max 66.5 WG + Trend 0.1 % and Arigo 51 WG + Trend 0.1% on the microbial activity of soil under maize plantation. The research included assessment of the count of selected groups of microorganisms, the activity of soil enzymes and soil fertility (BIF), as well as soil sensitivity (RS) to the preparations tested in the experiments. The results of study show that in some cases the count of the groups of microorganisms under study increased (the total bacterial count, the count of copiotrophs), especially immediately after the herbicide treatment, i.e. at the first term of analyses. The study showed that sixty days after the herbicide treatment all the xenobiotics exhibited strongly negative influence on the dehydrogenase activity (DHA). The activity of alkaline phosphatase and catalase became significantly reduced thirty days after the soil treatment with all of the herbicides used in the experiment. The highest values of biological index of fertility (BIF) were noted thirty days after the herbicide treatment and were strictly correlated with DHA and PAC.