Mass production of Alginate Entrapped Arbuscular Mycorrhizal Inoculum and their influence on growth and nutrition of Onion

Abstract :

The present study is aimed at developing wasteland through exploitation of Rhizobium and Glomus fasciculatum in association with Acacia mellifera and also identifying the optimum biomass accumulation in Acacia mellifera supplemented with nitrogen and phosphorus at five different dose rates (0,50,100,150 and 200 mg/kg of soil). The entire study was designed in low nutrients available soil collected from Marikundu (Theni District, Tamilnadu). Supplemental phosphorus in combination of Glomus fasciculatum and cowpea Rhizobium (Acm05) were inoculated. Plant biomass, total nitrogen content, and phosphorus content were estimated. Soil NPK content also determined. Initially the soil had high potassium content (115mg/kg soil) and low nitrogen (14mg/kg soil) and phosphorous (1.1mg/kg soil) content. In contrast, dual inoculation significantly enhanced the nitrogen (60.0mg/Kg soil) and phosphorous (24.3mg/Kg soil) contents of soil, but to a lesser extent with respect to potassium content (155mg/Kg soil).The supplemented nitrogen and phosphrous with Rhizobium and Glomus fasciculatum showed increased biomass (0.439g/plant), total nitrogen content (38.13mg N/g dry plant) and phosphorus content (5.16mg P/g dry plant) in dual inoculation at 200mgN /kg of soil). The nitrogen content was found to be higher in all dose rates of dual inoculated plants, specifically higher at 50mg P/kg of soil (22.83mg N/g dry plant).Acacia mellifera – cowpea Rhizobium (AcM05) Glomus fasciculatum association appears to be the best one in terms of accumulation of plant biomass, total nitrogen and phosphorus. Further, the aforesaid combination in nutrient poor unsterile soil is found to improve the soil activity such as soil NPK content, soil enzymes and soil microbial populations