Effect of cobalt and Rhizobium on yield, oil content and nutrient concentration in irrigated summer groundnut (Arachis hypogaea) - JANA, P K; KARMAKAR, S; GHATAK, S; BARIK, A; NAYBAN, A; SOUNDA, G; MUKHERJEE, A K; SAREN, B K (The Indian Journal of Agricultural Sciences, 2013)