Agricultural Biostimulants: What They Are and How They Work

Introduction

Agricultural biostimulants are natural products that improve plant growth and development by stimulating physiological processes. These products are designed to optimize nutritional efficiency, increase stress tolerance, and enhance crop quality. They use natural extracts and beneficial microorganisms that boost soil and plant health, resulting in more sustainable and profitable production for farmers. In a context of growing demand for sustainable agricultural practices and the need to reduce the use of chemical fertilizers, biostimulants emerge as a viable and effective alternative. In this article, we will explore in depth the mechanisms of action of biostimulants, their practical applications, and their impact on modern agriculture. For more information on differences and advantages, check out our article on biostimulants vs fertilizers differences. Additionally, trends in the use of bioprotectants in tropical crops and on biostimulants in organic farming will be addressed, as well as on biostimulants for tomato and agricultural biostimulants what they are.

How Do Biostimulants Work?

Biostimulants work through several mechanisms, such as:

• Stimulation of soil microorganisms: They increase the activity of beneficial microorganisms that improve soil health.
• Improved nutrient uptake: They facilitate the assimilation of essential nutrients by plants.
• Stress reduction: They help plants better manage stress situations, such as drought or diseases.

Stimulation of Soil Microorganisms

Biostimulants can have a significant effect on the soil microbial community. For example, some seaweed-based biostimulants can increase microbial diversity, which in turn can improve nutrient availability. A study conducted by the Department of Agriculture at the University of California revealed that the application of seaweed extracts increased the population of beneficial bacteria by 40% in agricultural soils, contributing to a more balanced and healthy ecosystem.

Furthermore, the activation of soil microorganisms can result in greater decomposition of organic matter, releasing essential nutrients for plants. According to research from the National Institute of Agricultural Research, it has been shown that the application of mycorrhiza-based biostimulants can increase decomposition activity by 25%, improving soil fertility and promoting more robust plant growth.

Biochemical Mechanisms of Stimulation

Biostimulants act at the biochemical level, promoting the production of secondary metabolites that are essential for plant growth. For example, seaweed extracts have been observed to induce the synthesis of phytohormones such as auxins and cytokinins, which are crucial for cell division and root elongation. A study from the University of Florida showed that the use of seaweed-based biostimulants increased auxin production by 30%, resulting in more extensive and efficient root development.

Improvement of Nutrient Absorption

Biostimulants can also improve nutrient absorption by modifying soil structure and facilitating the mobility of nutrients toward plant roots. For example, the amino acids present in certain biostimulants can act as chelating agents, helping to solubilize nutrients such as iron and zinc, which are essential for plant growth. A field trial on maize crops demonstrated that the application of an amino acid-based biostimulant increased leaf nutrient concentration by 30% compared to the untreated control.

Furthermore, biostimulants can influence the activity of soil enzymes involved in nutrient cycling. For example, certain plant extracts have been shown to increase the activity of phosphatase, a key enzyme for phosphorus release, by 50%, thereby improving the availability of this critical nutrient for plants. In the event of nitrogen deficiency in citrus, biostimulants can be an effective solution. For more information on nitrogen deficiency in olive trees, consult our related article on organic nitrogen in agriculture.

Interaction with Beneficial Microorganisms

Biostimulants not only benefit plants directly but also promote interaction with beneficial soil microorganisms, such as mycorrhizae. These symbiotic associations enable greater nutrient and water uptake. A study conducted on fruit crops showed that applying a biostimulant containing mycorrhizae increased phosphorus absorption by 60%, thereby improving plant growth and resistance to adverse conditions.

Stress Reduction

Biostimulants can help plants withstand adverse conditions, such as drought or diseases. For instance, seaweed extracts can induce the accumulation of osmoprotective compounds, which help plants manage water stress. A study on tomato crops showed that plants treated with seaweed-based biostimulants exhibited a 50% increase in fruit production under water stress conditions compared to untreated plants.

Additionally, certain biostimulants have been observed to activate plant defense pathways, making them more resistant to diseases. A trial on wheat crops demonstrated that applying a biostimulant based on plant extracts increased resistance to fungal diseases by 35% compared to the control, resulting in reduced fungicide use and an increase