AZOLLA BLOOM IN HANDIA AND JOGA- A COMBINED EFFECT OF UNUSUAL RAINFALL PATTERN IN WINTER SEASON AND EXCESS USE OF FERTILIZERS IN THE WHEAT FIELD.
Dr. C Sreelatha Kutty
ABSTRACT
An abundance of phosphorus, due to eutrophication or chemical runoff, often leads to Azolla blooms. We explored the association of climatic conditions (i.e. annual rainfall and average minimum temperature during March and April) and water quality (phosphate and nitrate concentrations) with blooms of the invasive fern Azolla in the Narmada River flowing through Handia and Joga during March and April 2015. In the last decade, there has been a considerable change in the climatic condition in India, winter season begins late and lasts until the end of March. The year 2015 has seen rainfall in January to April. The excessive use of phosphate fertilizers in the field is washed into the water bodies by the runoff water. A positive co- relation observed between the growth of Azolla sp. and nutrient concentration in the river. The study shows that Handia and Joga are facing eutrophication and invasion by Azolla sp., most notably due to low temperature in March and frequent rainfalls in February to April.
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