The use of microalgae as a slow-release biofertiliser has gained a lot of interest in the horticultural industry and become a popular research topic as a sustainable and efficient alternative to traditional fertilisers in recent years. Microalgae are fast growing and thrive easily in different water bodies, where they effectively assimilate several inorganic nutrient resources (primarily nitrogen, phosphorous, carbon, potassium and many micronutrients like iron, zinc and magnesium). Therefore, microalgae have been recognised as an effective bioremediation strategy for municipal wastewater treatment and the produced biomass may be used as a green fertiliser to supply nutrients to the plants. This is the research focus of our ALGECO project, aiming for a new paradigm to benefit both Norwegian wastewater treatment plants (WWTP) and the horticultural industry.
Unlike conventional fertilisers, which can be harmful to the environment, algae-based fertilisers are biodegradable and non-toxic. The use of algae-based fertilisers may improve the physical and chemical properties of soil, such as water retention capacity, soil agglomeration and microbial activity. Theoretically, they can promote plant growth and development. However, due to concerns about emerging contaminants in municipal wastewater, the produced algal biomass will be evaluated thoroughly in the ALGECO Work Package 4 (WP4).
ALGECO WP4 will assess the efficacy of filamentous algae-based fertiliser on typical Norwegian crops, focusing on soil and plant health, growth performance, quality control and safety assessment. At the preliminary stage, the microalgae are those generated by ALGECO WP2 that have previously been utilised for nutrient removal from the municipal wastewater effluent provided by Veas. Nutrient content analysis in the algae produced using municipal wastewater effluent have been performed with promising results, and our experiments at NMBU will soon be under way to test the effectiveness of algal biomass on several plant species.
Various methods will be used to investigate the nutrient uptake, transpiration and photosynthetic responses of the plants, as well as to measure stress levels. At harvest, the plants will be analysed for nutrient content and their growth rates will be measured against plants grown in traditional mineral fertilisers to compare the effectiveness of the microalgae as a fertiliser. Later on, the research will be extended to the formal by-products from the WP3, with the same microalgae biomass but processed by pyrolysis and anaerobic digestion treatment with a certain amount of sludge. An international collaboration will be involved in the WP4 with the scientists at NMBU, to specify the efficacy of our algae products on soil microbial communities. Dr Sheona Innes is an experienced plant scientist and will carry the research on the mentioned topics in the coming two years. For more information about the algae-based fertilisers and their benefits in our project, please contact us at Sheona.noemi.innes@nmbu.no, sissel.torre@nmbu.no or Jorunn.olsen@nmbu.no.
