The use of algae in agriculture is not a new concept. Literature attributes the initial use of algae as a fertilizer to the Romans. The first written account of the fertilizing nature of algae dates back to the ancient Romans when Columella in “Rustic” reported that the roots of seedlings should be wrapped in “seaweed” to preserve their greenness. It is noteworthy that the use of whole seaweed was not supplanted until the 1950s by the use of different types of extracts.
Several species of macroalgae are a rich source of nutrients and act as powerful biostimulants for plants. Algae extracts contain bioactive compounds that increase resistance to stress, improve nutrient absorption and plant growth.
Research in recent years has led to significant advances in understanding how algae act on crops. To explore these discoveries and their impact on modern agriculture, Marcelo Brintrup, research and development manager at PatBio and creator of the FERTUM® formula, together with Chiara Pituello, PhD in Plant Production Sciences and responsible for agronomic development at SICIT GROUP, explain the different factors that influence the role of algae in agriculture.
THE ROLE OF POLYSACCHARIDES
New knowledge about the action of algae in crops points to polysaccharides as the main responsible for the biostimulant activity in plants, says Pituello. These macromolecules promote the development and growth of plants “by modulating various metabolic processes (photosynthesis, cell division, nutrient absorption).”
Once polysaccharides bind to plant receptors, they trigger a series of responses that activate gene expression, which in turn enhances the defensive capacity of plants against abiotic stress.
Regarding biotic stress, although they do not have a direct action on pathogens, "these biostimulants provoke an indirect response to this type of stress, improving the plant's resistance."
SYNERGY OF COMPOUNDS
Beyond the specific effects of each compound in a plant extract, there is recent evidence showing that the positive response in the plant system is related to the synergy of the different compounds in the extract. “Polysaccharides, such as alginates, together with other active ingredients found in brown algae, such as vitamins, amino acids, hormones and oils, promote root growth, stimulate the natural defenses of plants, increase nutrient absorption by the plant and improve photosynthetic rates,” Pituello summarizes.
The benefits of algae do not only impact plants, but also soils, explains the representative of SICIT GROUP. “Another recent line of studies is the action of polysaccharides and nutrients from algae in the soil, where they function as prebiotics and probiotics for microorganisms such as beneficial mycorrhizal fungi, thus improving the absorption of nutrients such as phosphorus.”
PATAGONIA, HOME OF ALGAE WITH UNIQUE CHARACTERISTICS
Although the most commercially recognized algae are Ascophyllum and Ecklonia, the algae of Chilean Patagonia, particularly Macrocystis and Durvillaea, “they have enormous potential, with unique characteristics that are in no way inferior to the first ones.” This is explained by Marcelo Brintrup, who has more than 25 years of experience studying the properties and agronomic benefits of Patagonian algae.
The specialist maintains that at PatBio they have studied and corroborated the contributions in nutrients and polysaccharides of the families of red and green algae, Pyropia and Ulva lactuca Specifically, these algae, which are part of the FERTUM® formula, provide other active compounds such as carrageenans and ulvans, generating good responses in the plants.
“Carrageenans increase metabolic activities such as cell division, photosynthetic and basal metabolic capacity, and REDOX capacity, all of which translate into greater plant development. Ulvans, on the other hand, increase the assimilation of carbon, nitrogen and sulphur, the length of the main root and improve plant metabolism during the vegetative period, which translates into an increase in biomass and the fresh and dry weight of the plants,” explains Brintrup.
CHEMICAL COMPOSITION OF AN EXTRACT DEPENDS ON SEVERAL FACTORS
The more hostile the environment, the stronger the living being. This is how Brintrup describes the differences between algae extracts according to environmental, genetic or extraction process characteristics, factors that influence the chemical composition of the extract. Thus, algae collected in the cold waters of Patagonia have a different composition to algae that grow in South Africa, where the waters are warmer.
“Patagonian algae have evolved to withstand the low temperatures of the Humboldt Current, becoming tolerant to constant stress. This exposure to low temperatures, waves and currents can result in a higher concentration of certain bioactive compounds and mechanisms of tolerance and stress mitigation that we believe can be transferred to plants through extracts,” says the expert.
Regarding the extraction process, Brintrup mentions that it is one of his current areas of study, where he uses cutting-edge biotechnological techniques. “The idea of the extraction process is to be able to obtain the active ingredients that are inside the cells, such as amino acids, polysaccharides, vitamins and phytohormones. However, this process must be as minimally invasive as possible, breaking the cell wall without significantly altering the active ingredients and the biological properties of the cellular compounds.”
THE IMPRESSIVE GROWTH OF MACROCYSTIS PYRIFERA
One of the most amazing facts that Marcelo Brintrup shares is that Macrocystis pyrifera as the protagonist. This brown algae can grow up to 15 centimeters per day under optimal conditions, making it one of the fastest growing organisms. As a reference, Ascophyllum nodosum It has a growth rate of 5 to 15 cm per year.
Its rapid growth rate, combined with the fact that it is a cultivable species, facilitates the production of biomass in a very short time. “The cultivation of this algae is one of our current focuses, in order to migrate to a more sustainable extraction of the resource. This year, we plan to plant an area of 16 hectares of algae,” shares the R&D manager of PatBio.
Growing algae in-house is not common in companies that sell algae extracts. According to Brintrup, “it allows us to better manage quality because we harvest when there is an optimal balance between biomass and concentration of active compounds, and it also gives us guaranteed and sustainable access to raw material.”
BIOSTIMULANTS TO FACE CLIMATE CHANGE
The effects of climate change are becoming more and more intense, and agricultural producers have had to adapt to current conditions while preparing for future ones. In this regard, Marcelo Brintrup highlights the importance of using natural biostimulants.
“Climate change and soil degradation are critical challenges for modern agriculture. Natural biostimulants, such as algae extracts, offer a sustainable solution to improve soil health and plant resilience.” Such solutions can help plants resist the effects of environmental stress, improve nutrient use efficiency and reduce reliance on chemical fertilizers. “This not only promotes more sustainable agriculture, but also contributes to food security in an ever-changing world,” he says.
Via: biologicalslatam.com.
