title: Effect of seasonal changes on cyanobacterial production and nitrogen-yield.
abstract: A mixed culture of cyanobacteria (BGA) containingAulosira sp.,Aphanothece sp., andGloeotrichia sp. were grown throughout the year to assess the influence of seasonal variables on their biomass production and nitrogen (N)-yield under field conditions. The seasonal variables considered in this study, i.e., water temperature (maximum, minimum), solar radiation, sunshine hours, and rainfall, fluctuated widely. Attempts were made to establish a relationship between seasonal changes as independent variables and BGA productivity and N-yield as dependent variables. The analysis indicated that solar radiation was the prime factor. Estimates of BGA biomass production varied from 3.3 to 366.5 kg (dry wt)/ha/month, and N-yield ranged from 0.1 to 11.8 kg N/ha/month. The nitrogen accumulated during the study period was 71.2 kg N/ha. The variations explained by seasonal changes were 52.3 and 50.3% for biomass production and N-yield of BGA, respectively.
authors.affiliation: Central Rice Research Institute, Laboratory of Blue-Green Algae, Cuttack 753006 Orissa, India.
authors.forename: R N
authors.initials: RN
authors.lastname: Bisoyi
authors.forename: P K
authors.initials: PK
authors.lastname: Singh