Possibility of using biomass of microscopic algae cultivated under flue gas conditions as an organic fertilizer

The use of microalgae grown during the utilization of CO2 from flue gases as organic fertilizers opens up new perspectives for simultaneously solving two of the most significant problems of our time - decarbonizing production processes (by reducing CO2 emissions from fuel combustion) and enhancing the agricultural sector’s productivity (through increasing crop yields). Given the availability of developed technologies for the disposal of CO2 from flue gases, which are a continuous source of microscopic algae growth, it is important to explore the possibility of using the resulting biomass for use as fertilizer. Two types of biofertilizers based on two cultures of microalgae Chlorella sp. grown in the presence of flue gas were studied. The first culture was obtained from the biological agents «Spirulinafood». The second culture was a consortium of green microalgae of various species, with a predominance of Chlorella sp. It was isolated from a freshwater pond. A study of the effectiveness of biofertilizers has shown an increase in the length and weight of aboveground rapeseed seedlings. The optimal application conditions include dilution of the solutions with a biomass content of 2.4-2.8 g/dm3 and an optical density of 1.3-1.5, in a ratio of 1:9. This provides an increase in seedling length by 13% and weight by 13% The use of biofertilizer from a pure culture of Chlorella sp. (the biological agents «Spirulinafood») allowed to increase seed germination energy by 6% and the percentage of seed germination, and an elemental analysis revealed an increase in the content of magnesium and phosphorus in the composition of the fertilizer. The results obtained confirm the prospects for further research and the inclusion of biofertilizers from microalgae cultivated in flue gas conditions in modern agrotechnological processes