Question

Farmers have reported over 50% higher yields of rice by using which of the following biofertilizer?

• A. Mycorrhiza
• B. Azolla pinnata
• C. Clostridium
• D. Rhizobium

Answer 1

Answer: (B)

Azolla pinnata

Farmers have reported over 50% higher yields of rice, by using Azolla pinnata as biofertilizer. Azolla is a free-floating water fern that floats in water and fixes atmospheric nitrogen in association with nitrogen fixing blue green alga Anabaena azollae. Azolla fronds consist of sporophyte with a floating rhizome and small overlapping bi-lobed leaves and roots. Rice growing areas in South East Asia and other third World countries have recently been evincing increased interest in the use of the symbiotic N${}_2$ fixing water fern Azolla either as an alternate nitrogen source or as a supplement to commercial nitrogen fertilizers. Azolla is used as biofertilizer for wetland rice and it is known to contribute 40-60 kg N/ha per rice crop.

So, the correct answer is option B.