Biostimulants: A Complete Guide on the Role & Impacts on Plant Growth

The agriculture sector has been facing significant challenges of low productivity in plants due to human activities. As the world’s population grows, requirements for food also increase exponentially.

Still, the pressure of climate change, water and wind erosion, salinity, loss of organic matter, environmental pollution, disease-spreading pests, and abiotic stress have led to the loss of crop productivity.

Biostimulants’ are novel approaches that focus on stimulating plant nutrition processes by improving one or more of the characteristics of the plant, such as nutrient use efficiency, tolerance to abiotic stress, quality traits, and availability of confined nutrients in the soil.

Microbial biostimulants are biologically natural or synthetic substances that can promote plant growth, improve plant quality, reduce plant abiotic stress, and enhance nutrient uptake.

Microbial biostimulants are introduced to preserve nature as the newest group of agricultural inputs in agriculture, an unknown product for most farmers today.

Effect of Abiotic Stress on Crops?

Abiotic stress is the nature of plants reacting to climate change, soil salinity, and drought.


Drought is the most common stress factor for plants; it leads to physiological, morphological, ecological, biochemical, and molecular traits that affect plant growth quality and quantity.

When biostimulants are applied to plants with low fertility and water availability, it reduces the need for fertilizers by increasing their productivity and reducing water and climate stress.

Water stress can damage the cells of plants, but the action of antioxidants, reinforced by biostimulants, can decrease toxicity and increase the defence system of plants.

Plants with high antioxidants improve root and shoot growth, which maintains high water content and can have a low incidence of diseases.

Water stress impacts several aspects of plant growth, with the most common effects of water stress being the reduction of plant size, leaf area, and crop productivity.


Another cause of abiotic stress is soil salinity. Salinity has the greatest impact because it has reduced the area of cultivated land and thus limited possibilities of heightened food yield.

Fifty percent of the world’s arable land is estimated to be affected by salinity in the next thirty years.

With salts in the soil, water inhibiting plant growth by reducing the ability for plants to take up water, or excessive amounts of salt entering the plant can only reduce plant productivity.

These salinity effects cause imbalance or disturbances in ion transfer and toxicity, altering the plant’s initial growth.


Plant productivity is also affected by temperature stress, which is classified into three types. The three stress types depend on high, chilling, or freezing temperatures.

Stressed plants usually have signs of low germination rates, growth retardation, and reduced photosynthesis.

So, How Do Microbial Biostimulants Help Plants With Abiotic Stress?

Plant growth-promoting bacteria (PGPB) are naturally located in the soil environment and usually migrate to the rhizosphere and rhizoplane, while some move to the aerial parts of the plants.

An advantage of microbial biostimulants is that they’re sold commercially and are ready to use after a simple dilution.

The ability to produce growth regulators responsible for N2 fixation creates a hostile environment for phytopathogens and can induce the solubilization of mineral phosphates.

In case of countering drought stress, microbial stimulants help create higher organic carbon content in the soil and produce exudates that act like glue to improve soil water retention and improve the absorption of water through root hairs as well.

These very same mechanisms work against temperature stress as well.

Microbial biostimulants can exert a plant growth-promoting effect to counteract the negative effects of soil salinity. Microbial biostimulants can improve shoot and root weight.

The main growth-promoting mechanisms of microbial biostimulants involve the production of growth-promoting phytohormones, solubilization and mobilization of nutrients, and immunity against pathogens.

In conclusion, while microbial biostimulants seem to be the key to improving plant productivity, ensuring good quality and proven performance is crucial to adaption of this product category.

Organica Biotech creates research-backed and technology-driven products to help combat the key problems that plague agriculture today.

Our diverse and effective range of microbial biostimulant products is the best in the business and can help ensure unbeatable performance while taking steps toward sustainability.