Impact of Rhizobium biofertilizer on agronomical performance of lentil (BARI Masur-6) in Bangladesh

Excessive nitrogen fertilizer uses in crop field causes surface water pollution, which has a harmful effect on the ecosystem. The study was conducted to reducing the use of nitrogen fertilizers during cultivation of pulse crop and as an alternative to increase the use of biofertilizers. Rhizobium can fix atmospheric nitrogen to the soil; it can be used as an alternative to urea for the cultivation of lentil (BARI Masur-6). The Rhizobium leguminosarum was isolated from root nodules of lentil (Lens culinaris) plants and cultured in YEMA (Yeast Extract Mannitol Agar) media. The Rhizobium was screened on the ground of physiological, biochemical and environmental conditions. Different doses of urea fertilizers (20, 40, 60, 80 kg ha-1) and liquid Rhizobium were used in experimental plots. The results indicated that biofertilizer with different chemical fertilizer performed higher than application of several level of urea nitrogen fertilizer in respect of plant height, number, chlorophyll content (µg cm-1) and number of nodules plant-1 with variety BARI Masur-6. There was optimum relative growth rate (RGR) also observed. The increase in urea nitrogen levels was the reason for the decline in relative plant growth. Yield and yield contributing characters like number of pod plant-1, number of seed plant-1, 1000-grain weight (g), grain yield (t ha-1), straw yield and biological yield were significantly influenced by biofertilizer application. The assembled application of biofertilizer and chemical fertilizer produced maximum number of harvest index (%) compare to the chemical fertilizers. Significant correlation found with no of nodule, no of seed, seed weight, grain yield and straw yield. Significant correlation also found in chlorophyll content with some yield contributing characters like seed number, seed weight, grain yield and straw biomass. Further significant correlation observed between pod number and seed number, between seed weight and grain yield. Rhizobium can fulfill the alternate source of nitrogen that promoted significant growth and yield of lentil and it was much closer to the farmer’s conventional amount of urea.