Impact of herbicide mixtures on earth worm population, organic carbon content and β glucosidase enzyme activity in soil Raj Sheeja K*,2, Syriac Elizabeth K1,2 2Coconut Research Station, KAU, Balaramapuram, Thiruvananthapuram, Kerala, 695 501 1Department of Agronomy, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, 695 522 *Corresponding author: sheejakraj70@gmail.com
Abstract Earthworm population, soil organic carbon content and β glucosidase enzyme activity in the soil are considered as the indicators of soil quality and biomarkers for toxicity and bioaccumulation assessment. Hence, field experiments were conducted during first crop season (Kharif 2014) and second crop season (Rabi 2014–15) to study the impact of pre- mix herbicide mixtures bispyribac-sodium + metamifop and penoxsulam + cyhalofop-butyl on earth worm population, soil organic carbon content and β glucosidase enzyme activity in soil. The experiments were conducted in randomized block design with 12 treatments and three replications at Upaniyoor Padashekaram in Thiruvananthapuram district of Kerala, India. The treatments were bispyribac-sodium + metamifop at 60, 70, 80 and 90 g/ha, penoxsulam + cyhalofop-butyl at 120, 125, 130 and 135 g/ha, bispyribac-sodium applied alone 25 g/ha, penoxsulam applied alone at 22.5 g/ha, hand weeding twice and weedy check. All the herbicide treated plots registered earthworm population at par to weedy check and hand weeding. The organic carbon content in soil was higher in herbicide treated plots as compared to weedy check at all the stages of crop growth. Herbicide treated plots were comparable to non-herbicide treated plots with respect to glucosidase activity. It was concluded that the pre-mix bispyriibac-sodium + metamifop and penoxsulam + cyhalofop are environmentally safe. Top Keywords Earthworms, β glucosidase enzyme activity, Herbicide impact, Non-target organism. Top |