Cyanobacteria in South Asia

An experiment was carried out on the saline soil of Satkhira during the aman season of 2000 in order to test the effectiveness of the produced cyanobacterial moculum on rice yield, soil fertility and soil salinity. The modem rice variety BRRldhan 31 was used as the test crop. There were six treatments for the experiment viz. T1 (control), T2 (RFD), T3 (RFD-20%N), T4 (RFD-20%N + Cyanobacteria), T5 (RFD-40%N) and T6 (RFD-40%N + Cyanobacteria). Eight cyanobacterial strains were isolated, identified and brought under pure unicyanobacterial cultures from the selected location. Out of eight isolates, only five isolates were fast growing and four isolates were capable of fixing high nitrogen. The fast growing isolates did not always show high nitrogen fixing capacity. Among the isolates, growth rate and nitrogen fixation capacity were high in Anabaena, Scytonema and Westiellopsis and these isolates were selected for biofertilizer production. The experiment was laid out in Randomized Complete Block Design with 4 replications of each treatment. Cyanobactenal inoculum was applied at the rate of 20 kg/ha in two equal splits-7 and 30 days after transplanting. Results of field trials indicated