Intensive use of synthetic chemicals in crop cultivation is indispensable for obtaining high crop yields. On the other hand, excessive use of these substances disturbs the biological balance and leads to contamination of the soil environment. Soil resistance to this type contamination depends on its physical, chemical and biological properties. Persistence of chemical substance in soil plays a fundamental role in environmental pollution. Therefore, it is important to monitor the duration of the action of a chemical agent applied to the soil environment. Soil microorganisms with their enzymatic activity are the best indicators of soil contamination with chemical compounds. The aim of this study was to evaluate the influence of active ingredient (glufosinate ammonium) of the Basta 150 SL herbicide on microbial activity and chemical properties of soil under winter oilseed rape cultivation. The investigations on the duration of action of the Basta 150 SL herbicide (glufosinate ammonium as an active ingredient) included a three-year field experiment set up on soil representing the class of black soils. The Basta 150 SL chemical agent was applied to the soil at a dose recommended by the producer (2.5 dm3 ha-1) and at a 10% higher dose (2.75 dm3 ha-1). Soil was sampled for analyses in 8 periods, i.e. immediately after winter rapeseed harvest, and next after 2, 10, 12, 14, 22, 24, and 26 months of the experimental period. The study demonstrated that the dose of the chemical agent had a substantial effect on the intensification of the ammonification and nitrification processes. The increased dose resulted in a significant decline in the rate of the studied processes. Soil application of the dose recommended by the producer caused a significant decrease in the proteolytic activity. Additionally, it was found that the doses applied did not exert any significant effect on the urease activity in soil. After application of Basta 150 SL at the recommended dose, the pHKCl values and C:N ratio were reported to be higher.

19.1.2014