The Azolla filiculoides fern— with leaves the size of gnats, is considered a wonder-plant that played a pivotal role in cooling our planet 50 million years ago. Among its many properties, the Azolla can capture CO2 and nitrogen from the air and has genes that provide insect resistance.
Some 50 million years ago, however, the planet was a much hotter place and Azolla grew as far north as the Arctic Ocean. Fossil records show that, fueled by abundant nitrogen and carbon dioxide, the fern formed thick mats across the entire ocean and crept onto the surrounding continents. Over the course of 1 million years, the plant pulled an estimated tens of trillions of tons of CO2 from the atmosphere, which scientists believe helped cool the planet to a climate more similar to what Earth has today.
Azolla filiculoides is a water fern and has been used as “green manure” in rice paddies in Asia for well over 1,000 years because of its symbiotic relationship with the cyanobacteria Nostoc azollae. The fern and the bacteria work together to capture nitrogen from the air and convert it into something the fern and other surrounded plants can use. This eliminates the need for nitrogen-added fertilizers.
Scientists are hopeful that they will be able to use genomes from the natural bio fertilizer of the plant to help lead to future sustainable agricultural practices.
