As a part of foldscopic field survey, we have chosen different rice field in our area. Rice is an exclusive crop plant of aquatic habitat, largely raised in an anaerobic or partially anaerobic submerged environment. Diversity of rice fields provides favourable environment for the growth of various group of algae with respect to their requirement of light, water, temperature and nutrient availability.
Among the algal taxon Cyanobacteria (eg. Spirogyra, Nostoc etc) are an ancient group of unique prokaryotic organisms with the ability to perform mutually compatible functions like nitrogen fixation and photosynthesis. The capacity of several cyanobacteria to fix the atmospheric nitrogen is a significant biological process of economic importance. The green algae play the important role acting as primary producer and also increase the fertility of the soil in paddy fields.
Keeping these views in mind an attempt has been made to survey the distribution of the green algae in certain paddy field in and around Kokrajhar, Assam. In this study we have recorded three species of Spirogyra along with other Chlorophycean algae (Desmid) like Closterium, Cosmarium