Comparative performance of plant growth promoting Rhizobacteria with rhizobia on symbiosis and yields in Urdbean and Chickpea

Field experiments were conducted at Pantnagar during 2011–12 to evaluate the co-inoculation effect of different plant growth promoting rhizobactera (PGPR) strains with rhizobia in urdbean and chickpea on symbiosis, productivity and soil health. Experimental soil was sandy loam of neutral in reaction and medium in organic C, low in available N and medium in available P and K. Inoculation of Rhizobium sp. in urdbean and Mesorhizobium sp. in chickpea alone showed marginal increase in nodulation, plant dry matter, grain and straw yields, N uptake, organic C and available N and P in soil. However, co-inoculation of Rhizobium sp. with different PGPRs in urdbean recorded significant increases of 12.1 to 50.3 per cent in nodule number, 26.1 per cent in nodule dry weight and numerical increases of 8.2 to 28.9 per cent in grain yield over uninoculated control and 5.6 to 41.7, 4.5 to 26.1 and 2.3 to 21.8 per cent over Rhizobium sp. alone, respectively. Different PGPR with Mesorhizobium sp. in chickpea produced significantly more nodule number (8.3 to 32.5%), nodule dry weight (7.3 to 30.1%), grain yield (3.4 to20.7%) and straw yield (5.9 to 11.7%) over Mesorhizobium sp. alone. It also resulted in significant increases in soil organic C of 3.9 to 10.6% and soil available P content of 15.1 to 37.6% over uninoculated control and 2.0 to 8.5% and 13.2 to 35.4% over Mesorhizobium sp. alone, respectively. Application of Rhizobium sp. with PUK-171 in urdbean and Mesorhizobium sp. + LK-786 in chickpea were found superior to other treatments by registering highest nodulation, yields, N uptake and soil organic C and available N and P.