Research evaluates microalgae for fertilizer production

Research being conducted at the University of Passo Fundo (UPF) is investigating the potential of microalgae for the production of fertilizers and agricultural biostimulants by recovering nutrients present in mineral waste. The study, carried out in the Postgraduate Program in Civil and Environmental Engineering (PPGEng), seeks to use microalgae to solubilize phosphorus and potassium contained in rock powder, making these nutrients more available for absorption by plants.

The research is being developed by postdoctoral researcher Alan Rempel, master's student Julia Lorenzato, and doctoral candidate Viviane Simon, under the guidance of Professor Luciane Maria Colla, with support from researchers in the Postgraduate Program in Agronomy (PPGAgro).

According to Rempel, the proposal is to take advantage of the metabolism of microalgae to incorporate nutrients into the biomass produced, generating products with potential agricultural use. "We intend to develop more sustainable biofertilizers and biostimulants, reducing dependence on conventional fertilizers and promoting the use of waste generated by other productive activities," he explains.

Circular economy

The initiative aligns with the principles of the circular economy by seeking to add value to mineral waste that typically has low economic potential. Activities include chemical and mineralogical analyses of the materials, as well as the cultivation of different microalgae species, such as Scenedesmus obliquus, Spirulina platensis and Chlorellasp., to assess its ability to grow in the presence of residues and make nutrients available to plants.

During the experiments, researchers monitor indicators such as cell growth, available phosphorus concentration, enzymatic activity, protein production, and synthesis of bioactive compounds.

After the laboratory phase, the materials produced are tested on seeds and plants to evaluate their effects on germination, root development, vegetative growth, and productivity.

Potential for agriculture

In addition to providing nutrients, microalgae produce compounds such as amino acids, vitamins, antioxidants, and plant hormones, which can act as biostimulants and promote crop growth.

According to researchers, the application of these products can contribute to improved nutrient absorption, increased plant resistance to stress conditions, and reduced need for chemical fertilizers.

For Rempel, technology can represent an important alternative in the face of the challenges faced by agriculture, such as production costs, dependence on imported fertilizers, and the search for more sustainable production systems. "In addition to the economic and environmental benefits, research can contribute to food security, reducing external dependence on fertilizers, and strengthening agricultural practices aligned with sustainability," he emphasizes.