Effect of Biofertilizer on Nodulation of Pea (Pisum Sativum L.) in Alluvial Soil

An explorative trial was conducted during rabi season of 2000–01, 2001–02 and 2002–2003 in the institute's research farm to study the effect of biofertilizers on nodulation properties of popular genotypes of garden pea (Pisum sativum L.). The experiment was conducted in a factorial design with Azospirillum, Azotobacter, Rhizobium and phosphate solubilizing microorganism (PSM) in Arkel, Azad P 1 and Azad P 3 genotypes of pea. The nodule number, nodule weight per plant, leghaemoglobin content and nitrogenase activity were increased linearly from active growth stage to peak at flowering and then declined towards maturity irrespective of genotypic variation and or microbial association in the rhizoplane of pea crop. The nitrogenase activity and leghaemoglobin contents were highly correlated (r=0.93) irrespective of varieties or treatments. The N fixation was highly correlated to the contents of leghaemoglobin (r=0.69) and nitrogenase activity (r=0.73) in pea. The higher leghaemoglobin content and nitrogenase activity was indicative of the preference of Azad P 1 to Rhizobium, Azad P 3 to Azotobacter and Arkel to PSM for symbiotic N fixation.