Abstract
Salinity is one of the most serious abiotic stresses that cause reduction in plant growth and yield. A field experiment was conducted at Satkhira (Bangladesh) in 2010-2011 to evaluate salinity tolerant rhizobia strains isolated from saline area. There were seven biofertilizer treatments viz, five rhizobia strains L-19, L-68, L-292, L-304 and L-335 along with un-inoculated control (L-0) and 30 kg N ha(-1) as urea (N30). Two lentil cultivars named Binamasur-2 and Barimasur-3 were used as varietal treatments to see the response of lentil to salt tolerant rhizobia. The experiment was laid out in a split plot design using lentil cultivars in main plots and rhizobial inoculants in sub plots with three replications. Soil used in the study was with 1.15% organic carbon, 171 mg kg(-1) available nitrogen, 5.23 mg kg(-1) available phosphoms, 72.5 mg kg(-1) available potassium and 5.5 dS m(-1) electrical conductivity. Data on nodulation, growth, yield, yield attributes and nitrogen uptake were recorded. Plant and soil samples were analyzed for nitrogen. All the salt tolerant rhizobia inoculants were found effective in nodulation, growth, yield, nitrogen fixation as well as soil nitrogen saving. Inoculation increased nodule number by 3.82 - 12.96 folds and nodule dry weight by 4.78 - 16.86 folds over un-inoculated control. Plant height and shoot dry weight were significantly increased due to rhizobia inoculation. Grain yield and stover yield were improved significantly by the application of rhizobia inoculants The highest grain yield was obtained in rhizobia inoculant L-19 (1313 kg ha(-1); 39.7% higher over control) followed by L-304 (1309 kg ha(-1)). Number of pod per plant, seed per pod and 1000 seed weight were improved by 23.57 to 39.32%, 8.62 to 12.93% and 6.67 to 9.15%, respectively due to inoculation. Significantly higher (100.82-113.16 kg ha(-1)) total nitrogen (grain and stover) were increased due to biofertilizer application. Inoculation saved soil nitrogen by 61 to 70 kg ha(-1). Inoculant strains L-19 and L-304 showed superior growth, nodulation, yield, nitrogen uptake and nitrogen saving in soil over control and inoculant L-68, L-292 and L-335. Rhizobia inoculant strains L-19 and L-304 can be used as biofertilizer for lentil production in saline area. (C) 2013 Friends Science Publishers