IMPROVEMENT OF EDAPHIC CYANOBACTERIAL POPULATION THROUGH LIMING IN RED AND LATERITIC RICE SOILS OF WEST-BENGAL

In view of the predominance of acidic pH levels in lateritic soils and of the importance of this soil property on growth and distribution of blue-green algae or cyanobacteria (CB), the effect of lime applicatio n on the reduction of acidity and subsequently on growth and some rela ted physiological properties of CB have been studied. Four soils with varying pH levels were used for this purpose and three lime treatments corresponding to 0, 50 and 100 % lime requirement were applied to eac h of them. The soils thus treated were incubated under submerged condi tion in an illuminated chamber for 6 weeks and were drawn at weekly in tervals for studies of the number, fresh mass and chlorophyll content of the developed algal mass. Increase of the pH value of the soil thro ugh application of lime improved growth and relevant physiological pro perties of the CB.