Impact of Fungicides Chlorothalonil and Propiconazole on Microbial Activities in Groundnut (Arachis hypogaea L.) Soils

Introduction of agrochemicals (fungicides) into soil may have lasting effects on soil microbial activities and thus affect soil health. In order to determine the changes in microbial activity in a black clay and red sandy loam soils of groundnut (Arachis hypogaea L.) cultivated fields, a case study was conducted with propiconazole and chlorothalonil to evaluate its effects on soil enzymes (cellulase and invertase) throughout 40 days of incubation under laboratory conditions with different concentrations (1.0, 2.5, 5.0, 7.5, and 10.0 kg ha(-1)). Individual application of the two fungicides at 1.0, 2.5, and 5.0 kg ha(-1) to the soil distinctly enhanced the activities of cellulase and invertase but at higher concentrations of 7.5 and 10 kg ha(-1) was toxic or innocuous to both cellulase and invertase activities. In soil samples receiving 2.5-5.0 kg ha(-1) of the fungicides, the accumulation of reducing sugar was pronounced more at 20 days, and the activity of the cellulase and invertase was drastically decreased with increasing period of incubation up to 30 and 40 days.