Distribution of Nitrogen-Fixing Blue-Green Algae in Various Areas of South and East Asia

Abstract

De (i) was the first to suggest that the high fertility of rice fields in India and other tropical and subtropical regions of Asia may be at least partly ascribable to the activity of blue-green algae in fixing free nitrogen. These forms of micro-algae are ordinarily found abundantly in the shallow top water of the paddy fields in these regions. An extensive investigation of this group of organisms has been made by the present author with the purpose of obtaining fundamental data for the possible application of these algal forms as “green manure” in agricultural practice in this country {2y 3). Out of 851 samples1 of paddy field mud collected from various districts of South and East Asia (see Table 1), 16 species of blue-green algae were actually found to possess the capacity for fixing atmospheric nitrogen. Of these 4 have been isolated as pure cultures free from any contamination of bacteria. The results of physiological and biochemical investigations carried out with these blue-green algae have been published in the earlier papers of this series of studies (4, 5). The results of the preliminary steps towards practical application have also been described (6-10). The present paper will report data obtained with respect to the distribution of nitrogen fixing blue-green algae in various areas of South and East Asia. © 1959, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.