Einwirkung von umweltchemikalien auf bodenmikroorganismen und deren leistungen unter dem einfluß von düngung und pflanzenwuchs

Abstract

Summary A loamy sand soil with low microbial activity was treated under laboratory conditions with the herbicide “Aretit flussig” (dinoseb acetate) and its combination with the chemical PCP (pentachlorophenol). In addition to the unfertilized soil, fertilization with lucerne meal or NPK was also included. The higher Aretit dosage (10×) inhibited dehydrogenase activity, short-term respiration (CO 2 production for 12 h after glucose addition), long-term respiration (carbon mineralization within 14 d), as well as the populations of fungi and actinomycetes, whereas the bacterial population of the soil was increased. The normal dosage and its combination with PCP in most cases were less inhibitory. Fertilization caused only modifications to these effects, although large variations were found in the reaction towards ammonification and nitrification. In an additional glasshouse trial with and without plants Aretit inhibited dehydrogenase activity and short-term respiration in 2 soils. The extent depends on soil type, plant growth and sampling time. The chemicals PCP and LAS (sodium dodecylbenzenesulfonate), applied singly or in combination with Aretit, also reduced the microbial activity in some cases.