Azolla filiculoides

Azolla filiculoides is a unique floating water fern belonging to the Salviniaceae family. This plant is renowned for its symbiotic relationship with the cyanobacterium Anabaena azollae, which fixes atmospheric nitrogen, making Azolla an incredibly valuable biological resource for modern agricultural practices.

The original habitat of the plant spans the tropical and temperate latitudes of the Americas. Today, the culture has spread globally, including regions in Europe and Asia, where it is actively used both in natural bodies of water and in specialized agrotechnical systems to enhance soil fertility.

Botanically, the plant consists of small fronds with bilobed leaves that spread rapidly across the water surface. Azolla prefers still or slow-moving water bodies with soft water, requiring sufficient sunlight and temperatures ranging from +15°C to +25°C. It is extremely sensitive to frost, which can lead to the total collapse of the colony.

In agronomy, Azolla is cultivated as a valuable green manure, showing high efficiency in rice paddies. Thanks to its symbiosis with the algae, the biomass of the fern enriches the soil with nitrogen, allowing for a significant reduction in mineral fertilizer usage. Cultivation requires consistent water level monitoring and the application of phosphorus-based supplements to stimulate growth.

The economic use of Azolla extends beyond fertilization: it serves as a highly nutritious feed for poultry, livestock, and fish. Its rich protein composition and vitamin profile make it a cost-effective component of animal diets. Common pests include specific phytophagous insects, while typical diseases involve fungal infections caused by high planting density and stagnant water conditions.