Effect of Imidacloprid on the Microbial Biodiversity of Soils of Selected Zones of Haryana, India

Abstract

Imidacloprid is one of the most frequently used insecticide in Haryana having a pivotal role in pest management and improvement in crop yield production. This study was performed to investigate the consequences of Imidacloprid on bacterial, actinomycetes and fugal population in soils of selected zones of Haryana, India. The experiment was conducted for 28 days and the samples were taken after 1st, 7th, 14th, 21st and 28th day of Imidacloprid application at various concentrations like T1(1mg/kg), T2 (2mg/kg) and T3(10mg/kg) doses. The number of CFU (colony forming unit) of microbes were grown on appropriate media using serial dilution and spread plate method. The results obtained showed a negative effect of Imidacloprid at T1 and T2 doses in first two weeks of incubation but non-significant effect in last two weeks of incubation on soil microbial number. Imidacloprid stimulated number of heterotrophic bacteria and fungi at T3 with time but a negative effect of N2- fixing and phosphate solubilizing bacteria was observed at each dose and time point in each soil sample. Obtained results showed that these soil microbes were affected by concentration and treatment time of Imidacloprid significantly in soils of each selected zone of Haryana. The results provide a clue about the possible ecological effects of Imidacloprid.