Microalgae cultivated for the W2R project in Slovenia have a positive effect on plants and can be used in agriculture as biostimulants
The use of microalgae cultivated in wastewater as biostimulants for plants has emerged as one of the economically promising options in recent years, and positive effects of microalgae and their extracts in agriculture have already been shown in many studies. Microalgae can produce phytohormones, volatile fatty acids and are a rich source of amino acids, so they increase plant growth, development and stress response. Microalgae extracts can also inhibit the growth of plant pathogenic bacteria. By promoting plant growth and microbial activity in the soil, microalgae can also indirectly improve soil structure and porosity.
In Slovenia, on Algae Park at Biotechnical Faculty at the University of Ljubljana, the W2R microalgae mother culture (used for inoculation of the main microalgae pond in Matadero del Sur) is cultivated in open ponds. The microalgal biomass is constantly harvested, analyzed for its physio-chemical and biological properties, and treated with different processes to obtain biostimulants. The products are studied in laboratory and greenhouse experiments on plants for their biostimulant effects. It was shown that microalgae cultivated in Ljubljana have a positive effect on the germination of experimental plants and high auxin-like activity - the use of microalgae caused the development of more numerous and longer roots in experimental plants(1). In addition, the wastewater left after microalgae harvesting is used to grow vegetables in an experimental hydroponic system: a) less mineral fertilizer is needed for a comparable yield of vegetables; b) plants with a stronger root system grow in the algae water.
Spanish partner Kimitec recently produced the first microalgae-derived product (SRM-3 biostimulant) from biomass cultivated in the algae line in Spain and sent it to other partners across Europe for field testing. In Slovenia, UL is conducting the test on maize; the effects of SRM-3 on germination, growth, quality and yield of the crop are being studied.