Impact of Phytoplankton Biomass on the Growth and Development of Agricultural Plants

The agricultural sector plays a pivotal role in fulfilling the objectives set forth by the EU Green Deal. However, the extensive use of synthetic fertilizers has contributed to nutrient over-enrichment in aquatic ecosystems, promoting eutrophication due to excess nitrogen inputs from fertilizers. This phenomenon is a key driver of rapid and excessive algal blooms in rivers, lakes, and seas. In this study, three globally cultivated crop species – oilseed rape (Brassica napus L.), common wheat (Triticum aestivum L.), and pea (Pisum sativum L.) – were selected for experimental analysis. Various quantities of lyophilized phytoplankton biomass, collected from the Curonian Lagoon, a biologically productive and ecologically sensitive brackish water body in the southeastern Baltic region, were incorporated into the growth substrates of the studied plants. To evaluate the potential of phytoplankton biomass as a substitute for synthetic fertilizers, several biochemical parameters were assessed, including proline content, lipid peroxidation levels, hydrogen peroxide production, total phenols content, and antioxidant activity. The findings indicate that utilizing excess phytoplankton biomass can serve not only as a plant growth biostimulant but also as a sustainable alternative to synthetic fertilizers, thereby contributing to improved water quality and more environmentally responsible agricultural practices.