Use of Gold Ore Tailings (GOT) as a Source of Micronutrients to Sunflower (Helianthus annuus L.) in a Vertisol Divya S. (Author) M.Sc (Degree) Department of Soil Science and Agricultural Chemistry (Department) University of Agricultural Sciences, Dharwad (Institute) AC, Dharwad-580 005 Karnataka State, India (State) 2007 (Year Submitted) Th9438 (Accession Number) University Library, UAS, Dharwad (Location) Dr. K. K. Math (Major Advisor) ABSTRACT A field investigation was conducted on Typic chromsutert at Main Agricultural Research Station Farm, University of Agricultural Sciences, Dharwad during kharif 2006 to study the effect of GOT alone and with organic manures on growth, yield and uptake of nutrients by the sunflower, residual nutrient status and dehydrogenase activity in soil. The treatments included different levels of GOT in combination with organic manures namely FYM, vermicompost (VC), and poultry manure (PM). The experiment was laid out in RBD with fourteen treatments replicating thrice. Application of GOT @ 1.0 t per ha along with PM significantly improved yield attributing parameters and yield eventually resulting in 22.60 and 26.51 per cent higher seed and stalk yield of sunflower, respectively over control. The uptake of nutrients by the crop significantly increased over control due to application of GOT @ 1.0 t per ha along with poultry manure and was on par with treatments receiving same level of GOT alone and with FYM and VC. Similar trend was noticed with respect to residual nutrient status of soil. There was build-up in the residual status of micronutrients namely Cu, Fe, Mn and Zn in soil. Dehydrogenase activity in soil was not affected adversely in the treatment with 1.0 t per ha of GOT and there was significant increase in its activity when applied with organics. There was numerical increase in the lead accumulation in the treatments receiving both GOT and COT over control. The highest net return and B:C ratio was recorded due to application of GOT @ 1.0 t per ha alone. But use of organics is must for correcting the deteriorating soil health which is a pre-requisite for sustainable crop production. Therefore, application of GOT @ 1.0 t per ha along with organics is to be considered.