Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Viswa Vidyalaya, Kalyani, West Bengal
In an incubation experiment with ten alluvial rice soils of West Bengal, the potentiality of algal fixation of nitrogen was found to be 27.66 to 73.33 μg/g soil/week. The dominant genera in these soils were Nostoc, Anabaena and Cylindrospermum followed by Scytonema, Calothrix and Mastigocladus. The magnitude of fixation of nitrogen in soil culture and in mineral nutrient culture was found to be different. Among the eight unialgal species isolated, three of Nostoc and one of Scytonema were found to be efficient nitrogen fixers, Nostoc muscorum being the most, in media either with or without combined nitrogen
Nitrogen fixation, blue-green algae, rice soils
