KUMAR, N. GABDUL QAHAR, QARLUQ2017-01-192017-01-1940865Th-9666http://krishikosh.egranth.ac.in/handle/1/97051The impact of agrochemicals on the abundance of soil invertebrates were studied in undisturbed grassland ecosystem GKVK,UAS, Bangalore from October 2009 to April 2010.The evaluated agrochemicals included soil application of agrochemical i.e. phorate, carbofuran, neem cake, fertilizer and foliar application of insecticide (chlorpyriphos), acaricide (dicofol) and fungicide (bavistin) against litter and soil invertebrates. Cryptostigmata population in litter sample was affected by soil application of carbofuran and the order of toxicity was fertilizer = neem cake < carbendazim < dicofol = chlorpyriphos < phorate < control. However, chlorpyriphos was found to be more toxic to litter invertebrates during 10 DAT. Total litter acari was affected in plots received carbofuran and fertilizer and the order of toxicity was carbendazim > dicofol > neem cake > phorate > chlorpyriphos < control. Litter Collembola was affected in carbofuran treated plots. However, chlorpyriphos was found to be more toxic during 10 DAT. The order of toxicity to other litter invertebrates was carbofuran > chlorpyriphos = fertilizer = carbendazim = phorate = neem cake = dicofol < control. The order of toxicity to soil Cryptostigmata was carbofuran = carbendazim > dicofol = fertilizer > chlorpyriphos > phorate > neem cake < control. Toxicity of agrochemicals on soil other acari was more in carbendazim = phorate = carbofuran = fertilizer > dicofol > chlorpyriphos > neem cake < control. However, the order of toxicity to total soil acari was carbendazim = phorate = carbofuran = fertilizer = dicofol > chlorpyriphos > neem cake < control. The population of soil Collembola was affected in plots received carbofuran > chlorpyriphos > neem cake > phorate > fertilizer > carbendazim < control. Total soil invertebrates population was affected by carbofuran > chlorpyriphos > neem cake > phorate > fertilizer > carbendazim < control. Litter Collembola, Cryptostigmata and total acari showed negative association with bright sun shine hours. But total litter invertebrates and macrofauna showed negative correlation with maximum temperature and bright sun shine hours. The soil invertebrates showed positive correlation with soil parameters except available phosphorus and negative association with soil temperature, bright sun shine hours and total rainfall.enThesis