Azolla Cultivation at JAXA [November, 2010]

[Azolla cultivation at Japan Aerospace Exploration Agency. Photo: Erik Sjödin]

The Azolla Cooking and Cultivation Project was initially inspired by the paper Azolla as a component of the space diet during habitation on Mars published by researchers at the Space Agriculture Task Force at Japan Aerospace Exploration Agency in 2008.

In this paper the researchers “evaluate a candidate diet and specify its space agricultural requirements for habitation on Mars. Rice, soybean, sweet potato and a green-yellow vegetable have been selected as the basic vegetarian menu. The addition of silkworm pupa, loach, and Azolla to that basic menu was found to meet human nutritional requirements. Co-culture of rice, Azolla, and loach is proposed for developing bio-regenerative life support capability with high efficiency of the usage of habitation and agriculture area.” The researchers further suggest that “agriculture designed under the severe constraints of limited materials resources in space would make a positive contribution toward solving the food shortages and environmental problems facing humans on Earth, and may provide an effective sustainable solution for our civilization”.

In the paper the space agriculture researchers puts numbers on the nutritional value of Azolla and describe how Azolla can fit into a productive space agriculture system. They also briefly describe what Azolla tastes like and how it can be cooked:

“Azolla roots taste similar to Alfalfa sprouts, and the leaves resemble moss. However, the smell of Azolla might cause a problem of acceptance as food material. However, boiling Azolla reduces its smell to an acceptable level. Boiling is also important for storage of Azolla. Azolla contains 96.4% water, and its taste is crisp. Roots of Azolla can be cooked in many different ways, for example fried, sautéd, and baked or added to soup and salad. Leaves of Azolla are green or red in color. Red-colored Azolla leaves contain anthocyanins, which are known to show anti-oxidative function. This is good for healthy life in space.”

However, to get more satisfying answers to the question of how Azolla can bee used as a food stuff I decided to attempt to cultivate and cook the plant myself and together with farmers, gardeners and chefs.

In October 2010, after some initial cooking and cultivation attempts I was privileged to get to visit Prof. Masamishishi at the Space Agriculture Task Force at JAXA in Japan and learn more about Azolla and space agriculture.

[Azolla cultivation at Japan Aerospace Exploration Agency. Photo: Erik Sjödin]

The photos above show one of Prof. Masamishishi’s experimental Azolla cultivations. In this system Azolla is co-cultivated with rice and the edible salt water plant Saltwort (to the left). In a space agriculture system the water would contain re-circulated urine, which is salty. However, Azolla and rice are freshwater plants that don’t tolerate high salt levels. Therefore the Saltwort is used to remove salt from the water before it flows into the Azolla and rice cultivation.

Growing Azolla together with rice is not particular to space agriculture. Azolla has been grown in rice paddies and used as a green fertilizers and weed prevention for rice in Asia for thousands of years. When Azolla grows on the water surface in a rice paddy it blocks sunlight from entering the water, which prevents weeds from growing and competing with the rice. More importantly, Azolla is one of few plants that can fixate nitrogen, an essential plant nutrient, from the air. When the rice grows large enough to block the sunlight from reaching the Azolla the Azolla dies. It then sinks to the bottom of the paddy where it provides the nitrogen it has absorbed to the rice.