EFFECT OF AZOLLA APPLICATION ON RICE PRODUCTION AT MID-HILLS CONDITION OF NEPAL

Abstract

Azolla pinnata, a floating water fern, is used as green manure (bio-fertilizer) for increasing rice yields. It can fix di-nitrogen (N2) in association with Anabaena Azolla therefore helps to reduce the recommended dose of chemical-nitrogen when Azolla is applied to the paddy field. The species of Azolla has been collected from different parts of the country and maintained in the Soil Science Division, NARI, Khumaltar, Lalitpur. A field experiment was conducted at the Agronomy farm, Khumaltar to study and evaluate the effects of Azolla pinnata compared to other nutrient sources to the rice during 2015/16 and 2016/2017. The experimental design was a randomized complete block design (RCBD) comprising of 6 treatments and 3 replications. The rice variety used was Khumal-4. The results of the experiment revealed that incorporation of Azolla to rice field in combination with the recommended dose of Phosphorous and Potassium gave comparable yields to that of the recommended dose of Nitrogen, Phosphorous, and Potassium. Also, yields were comparable to that of the use of compost (10 ton/ha). The study indicates that Azolla could be a very good alternative supplementary source of fertilizer-N for rice production.