druppels op drijvende varen
druppels op drijvende varen

AZOPRO - Azolla farming on rewetted agricultural lands

A novel application combining phosphorus mining with the development of high-grade products

The development of new natural areas in the Netherlands often takes place on former agricultural soils. A major challenge in this transition is the enormous amount of nutrients built up in the soil from years of fertilization. In particular, high phosphate levels can lead to poor quality of soil and water as well as low levels of biodiversity.

AzoPro is focusing on an innovative method to combat this problem: growing Azolla. Azolla is a floating fern millions of years old. This small fern has a unique symbiosis with bacteria that live in its leaves, allowing it to extract nitrogen from the air. This allows Azolla to grow incredibly fast and absorb high amounts of phosphate from the water. By growing Azolla on wet agricultural soils, phosphate, a finite resource, is successfully recovered.

This process also improves soil and water quality, which is beneficial to biodiversity. Growing Azolla also provides an economically interesting product: for example, Azolla can be used in human food or as green manure or fodder in circular agriculture. In AzoPro, we investigate the key processes for the optimal growth and phosphate uptake of Azolla. To determine the climate impact of Azolla cultivation as an eco-tool, the uptake and emissions of greenhouse gases (carbon dioxide, methane and nitrous oxide) are also investigated.