Effects of EM on the Growth and Nitrogen Fixation Efficiency of Blue Green algae

Abstract

Effective Microorganism or EM is widely distributed to the farmers with diversity application purposes. The experiment was conducted at Soil Microbiology Research Group. Division of Soil Science to obtain the effect of EM on the growth and nitrogen fixation efficiency of Blue Green Algae (BGA). Five species of BGA, Nostoc sp., Calothrix sp., Tolypothrix sp., A. siamensis and A. royzae were cultured in N-free nutrient solution (BG₁₁) containing EM at the concentration of 0, 150, 300 and 600 ppm, respectively. Dry biomass, ARA and chlorophyll content were estimated as growth and nitrogen fixing efficiency parameter of BGA. Results found that the growth and nitrogen fixation of BGA in EM solution at the concentrations of 150 and 300 ppm were better than control. The growth reduction was found at the concentration of EM upper than 300 ppm.