title: Effect of some pesticides on certain micro-organisms, contributing to soil fertility.
abstract: A pot experiment was run for studying the effect of Temik (insecticide and nematocide), Orthocide (fungicide), and Treflan (herbicide) on certain desirable soil micro-organisms. Total counts of bacteria, actinomycetes or fungi were mostly lower in the treated than in the untreated soil. Aerobic cellulose-decomposers were either stimulated or depressed. Despite the temporarily slight stimulation, observed in some instances at the initial periods, the effect of the pesticides on counts of Azotobacter, N-fixing clostridia, and ammonifiers was afterwards depressed. The period of retardation or stimulation differed according to type of pesticide and type of micro-organisms under study. However, the autotrophic nitrifying bacteria, especially ammonium-oxidizers, seemed to be more sensitive and their counts in treated soil were sharply depressed.
mesh_terms: D000192:Actinomycetales / Q000187:drug effects*; D000383:Agriculture; D001419:Bacteria / Q000187:drug effects*; D005658:Fungi / Q000187:drug effects*; D005659:Fungicides, Industrial / Q000494:pharmacology; D006540:Herbicides / Q000494:pharmacology; D007306:Insecticides / Q000494:pharmacology; D010575:Pesticides / Q000494:pharmacology*; D012988:Soil Microbiology; D013045:Species Specificity
chemical_list: D005659:Fungicides, Industrial; D006540:Herbicides; D007306:Insecticides; D010575:Pesticides