Abstract

Phosphorus is one of the major essential macronutrients limiting plant growth owing to its low bioavailability in soils. Fertilizer phosphorus tends to be fixed soon after application and becomes mostly unavailable, low recovery by crops and a considerable phosphorus accumulation in soils. Several processes of the phosphorus cycle in soils remain obscure, despite large research efforts devoted to increasing the phosphorus availability to plants. The biofertilizer effect of phosphate solublizing bacteria on growth, yield and nutrient uptake of Oryza sativa was studied in a field experiment. Positive effect on plant growth, nutrient uptake, grain yield and yield components in O. sativa plants was recorded in the treatment inoculation of phosphate solubilizing bacteria (PSB). The PSB inoculated with O. sativa, increased significantly the average root length by 32.95%, average shoot length by 11.00%, numbers of roots by 38.46%, shoot biomass by 90.48%, root biomass by 3.77% as compared to control. The pigments increased the level of total chlorophyll by 68.70%, chlorophyll-a by 53.50%, chlorophyll-b by 80.47% and carotenoids by 45.83%, as compared to control and they also increase the level of carbohydrate by 33.33%, protein by 41.21% and amino acids by 30.23% as compared to control. Thus PSB is beneficial in raising vigorous of O. sativa under nursery and field conditions.

Key words: Biofertilizer, growth improvement, phosphate solubilising bacteria, Oryza sativa, root biomass.