Agricultural fertilization is undergoing a true silent revolution . While input costs rise and environmental requirements become stricter, technologies like nanotechnology and applied biology are changing the way we feed crops. It's no longer just about adding "more fertilizer," but about ensuring that every gram applied is actually utilized by the plant.
In this context, nanobiofertilizers have emerged , a new generation of products that combine nanoparticles and beneficial microorganisms to achieve much more efficient nutrition, reduce environmental impact, and improve soil health. They are, to a large extent, the missing piece needed to unite precision agriculture, sustainability, and high productivity in a single management approach.
What exactly are nanobiofertilizers?
When we talk about nanobiofertilizers (or bionanofertilizers), we are referring to formulations that integrate two key components: materials at the nanoscale (between 1 and 100 nanometers) and biological agents such as bacteria, fungi, or biomolecules that promote plant growth. This combination results in "smart" fertilizers capable of releasing nutrients in a controlled manner and actively interacting with the plant and the soil.
In practice, a nanobiofertilizer can contain essential nutrients encapsulated in nanoparticles (nitrogen, phosphorus, potassium, zinc, iron, boron, etc.), plant growth-promoting microorganisms (PGPB), or both. Thanks to their minute size and their specific polymeric coatings or nanostructures, these particles move easily in the soil, the rhizosphere, and throughout plant tissues.
Nanoparticles provide an enormous specific surface area and high reactivity , facilitating the solubility and availability of nutrients, while the biological component adds functions such as nitrogen fixation, phosphorus solubilization, phytohormone production , and protection against pathogens. All of this translates into greater nutrient use efficiency and a lower need for high doses compared to conventional fertilizers.
Commercial and experimental formulations range from "pure" nanonutrients (e.g., nanoscale zinc or iron oxides) to nanomaterials that transport nutrients or microorganisms on their surface or within their structure. Nanoemulsions and colloidal nanocarriers, based on micelles and biodegradable polymers, are also used; these are capable of delivering active ingredients directly into plant cells with minimal losses along the way.
Nanotechnology and biology: how they work at the nanoscale
The foundation of it all lies in nanotechnology, that is, the manipulation of matter between 1 and 100 nanometers . At that scale, materials begin to behave differently than they do at larger sizes, due to quantum effects and a much higher surface area to volume ratio. This allows for the design of particles with specific properties intended to improve fertilization.
To give you an idea, a nanometer is one billionth of a meter . A simple sheet of paper is about one hundred thousand times that thickness. Many biological processes also occur in this size range, which is why nanoparticles can interact with cell membranes, root pores, stomata, or leaf cuticles in ways that traditional fertilizers cannot.
In the agricultural sector, this technology is applied in various ways: improving the efficiency of fertilizers and pesticides , optimizing water use, and restoring degraded soils, among others. In Spain, public research organizations and private companies have been testing nanotechnology solutions for crops for over a decade, with projects at centers such as CSIC, IMIDRA, IFAPA, and several universities.
This work has resulted in three main families of solutions: simple nanonutrients or nanofertilizers , nanomaterials or nanocapsules that transport nutrients, and finally, efficient nanocarriers in the form of colloidal emulsions. These last act as "vehicles" that penetrate the leaf and root, depositing the treatment directly into the plant cells, with significant dose savings.
Nanotechnology is not limited to agriculture : it's present in 2-nanometer computer chips with billions of transistors, in lighter and more durable sports equipment, in cosmetics, smart food packaging, and water purification systems. This technological foundation is now being leveraged to redesign agricultural fertilization from the ground up.
Mechanisms of action of nanobiofertilizers
Nano dimension and biological dimension
The functioning of nanobiofertilizers is based on the synergy between the nanometric carrier and the biological component . On the one hand, the nanoparticles act as a transport vehicle: they adsorb or encapsulate nutrients and beneficial microorganisms, protect them from degradation, and carry them to the vicinity of the root or into the interior of plant tissues.
Thanks to their extremely small size , these particles can pass through root pores, leaf cuticles, and stomata, facilitating the rapid internalization and homogeneous distribution of encapsulated nutrients throughout the plant. Nanostructures such as metal oxides, nanoclays, or nanotubes provide support and increase the solubility of elements that, in their conventional form, tend to remain fixed in the soil.
On the other hand, the biological component relies on plant growth-promoting bacteria and fungi , as well as microbial consortia or PGPB that colonize roots, leaves, or internal tissues. These microorganisms fix atmospheric nitrogen, solubilize bound phosphorus, and produce phytohormones, siderophores, and other compounds that stimulate root development and nutrient absorption.
In the field of research, two major groups of beneficial bacteria have been identified: rhizobacteria, which are associated with the rhizosphere and live in close contact with roots, and endophytic bacteria, which colonize leaves, flowers, or internal tissues. Both have enormous potential for formulating biofertilizers and, when combined with suitable nanomaterials, become true nanobiofertilizers with far superior efficiency.
Recent studies have shown that silicon, zinc, titanium, or gold nanoparticles can increase the number of bacterial cells and enhance their beneficial properties for plants. In other words, the nanoparticle not only transports but also stimulates the performance of growth-promoting microorganisms, amplifying their effect in the field.
Controlled release and "on-demand" nutrition
One of the major differences compared to traditional fertilization is the ability to release nutrients gradually and in a targeted manner . Unlike soluble fertilizers that dissolve quickly and are lost through leaching or volatilization, nanobiofertilizers are designed to release nutrients over a prolonged period, better matching the plant's absorption rate.
This effect is achieved through nanoencapsulation with materials such as nanoclays, chitosan, or biodegradable polymers , or with nanometric coatings on the fertilizer granules. Release can be triggered by environmental conditions (humidity, temperature, soil pH) or by chemical signals emitted by the roots, and even by integrated biosensors that detect nutrient demand.
In the case of nanourea, for example, the particles are up to 10.000 times smaller than conventional granules and achieve utilization efficiencies exceeding 80%. This translates into more nitrogen available to the plant, fewer losses, and therefore lower pollutant emissions and better compliance with climate sustainability goals.
Controlled-release fertilizers (CRFs) incorporating smart coatings are a complementary element in this scenario. Technologies like eqo.x, already used in the European market , synchronize nutrient release with the crop's peak demand phases, reducing the number of applications and the risk of water contamination.
Biostimulating and protective effects
Beyond nourishing crops, many nanobiofertilizers play a biostimulating and stress-protective role . Certain nanoparticles can trigger defensive responses, activating antioxidant systems and metabolic pathways related to tolerance to drought, salinity, or pathogen attacks.
It has been observed, for example, that adding nano-calcium to cereals such as wheat increases the activity of antioxidant enzymes , improves photosynthesis, and strengthens resistance to oxidative stress. In this way, the plant is not only better nourished but also remains functional under adverse environmental conditions, something increasingly important due to climate change.
Furthermore, some nanoparticles (such as those of copper, silver, or zinc oxide) possess direct antimicrobial properties that help reduce the pressure of pathogenic fungi and bacteria in the soil and aboveground parts of plants. When integrated into nano-bio formulations, they contribute to lowering the incidence of diseases without the need to rely exclusively on chemical fungicides.
The result of this combination of improved nutrition, physiological stimulation and protective effect is greater crop resilience to biotic and abiotic stresses , maintaining stable yields even in challenging seasons.
Crops and fruit species where they are being most applied
Extensive crops: cereals and legumes
In extensive crops , nanonutrient fertilizers have been widely used in wheat, maize, and grain legumes . Field trials have shown increases in photosynthetic activity, improvements in antioxidant enzyme levels, and, in many cases, significant increases in grain yield when nanotechnology is used compared to traditional fertilizers.
In crops such as chickpeas and soybeans, zinc and iron nanoparticles have been combined with microbial inoculants (for example, Rhizobium added to the seed). This nano-bio approach has led to a greater number of nitrogen-fixing nodules, improved nutrition, and a clear increase in the number and weight of harvested seeds.
These results suggest that nanotechnology applied to fertilization is perfectly viable on a large scale for the production of staple crops, provided that the dosage and application method are adjusted. The goal is not to completely replace traditional fertilizers overnight, but rather to integrate them into more efficient and sustainable systems.
Horticultural and leafy crops
In vegetables, the use of zinc oxide nanoparticles has yielded particularly promising results . Increases in zinc use efficiency have been documented in crops such as cucumber, peanut, cauliflower, tomato, and pea when the micronutrient is applied in nano form instead of conventional salts.
These formulations allow the plant to achieve adequate zinc levels in its tissue with much lower doses , resulting in less product applied per hectare and fewer environmental losses. Nano-phosphorus and nano-nitrogen have been tested on leafy vegetables (lettuce, spinach) and root and tuber crops, yielding improvements in performance and quality, such as increased market weight and improved appearance.
In these types of crops, where the visual and nutritional quality of the harvested part is fundamental, nanobiofertilizers can be a key tool to produce foods richer in micronutrients without penalizing the producer with excessive costs or high environmental impacts.
Fruit trees, citrus fruits and red berries
The case of strawberries and other berries is particularly illustrative. In a field trial, foliar application of a nano-fertilizer resulted in up to 43% more fruit production and 45% more fruit per plant , in addition to advancing the harvest date compared to standard grower management practices. The root system became more robust, the plant developed greater leaf mass, and the number of fruit sets increased.
These data confirm that, even in sensitive and high value-added crops, a well-designed and managed nanobiofertilizer can make a difference in profitability , provided it is accompanied by good technical advice.
Benefits and advantages compared to conventional fertilization
The main reason nanobiofertilizers are considered revolutionary is that they allow you to do “more with less .” The applied dose may be lower, but the percentage that actually reaches and is utilized by the plant is much higher. This directly impacts costs, productivity, and environmental sustainability.
- Greater efficiency in nutrient use: Controlled release and proximity to the root drastically reduce losses due to leaching, runoff, or volatilization. In the case of phosphorus, for example, nanoforms keep it available for longer, preventing it from becoming bound in the clay-humus complex. Thus, The same or greater effect is achieved with less fertilizer applied.
- Optimized nutrient absorption: By increasing the solubility and mobility of nutrients in the rhizosphere, and by combining with mycorrhizal fungi or other beneficial microbes, plants show higher nutrient content in tissues when compared to conventional fertilization schemes with the same (or even higher) dose.
- Targeted and demand-adapted release: Nano formulations allow the design of products that release nutrients right where and when the plant needs themCoatings with biosensors or systems sensitive to chemical signals from the root offer the possibility of almost "on-demand" nutrition, reducing unnecessary applications.
- Less environmental impact: By requiring less fertilizer and reducing losses, it decreases the risk of water eutrophication and greenhouse gas emissions associated with nitrogen fertilization. Many of the materials used (chitosan, organic polymers, natural nanoclays) are biodegradable and leave no persistent residue in the middle.
- Improved soil health: The microorganisms provided by nanobiofertilizers can increase organic matter, improve structure and energize the soil microbiotaSoil with better aggregation and biological activity retains more water and nutrients, and better supports intensive crop cycles.
- Increased yield and crop quality: The tangible consequence for the farmer is that the plants grow more vigorously, produce more, and often with Superior quality parameters: size, color, sugar content, and nutritional valueAll this with a more rational use of resources.
- Greater tolerance to stress and disease: Some formulations induce the plant's own defense systems or incorporate nanoparticles with antimicrobial action, reducing the incidence of certain pathogens and improving tolerance to drought, salinity, or extreme temperatures. This aligns with the need to produce under an increasingly unstable climate.
Limitations, challenges and regulatory aspects
Despite their enormous potential, nanobiofertilizers are not a magic bullet and are not without challenges . They are a relatively recent technology in commercial agriculture, and there are still technical, economic, and legal issues to resolve before we see widespread adoption on all farms.
First, much more validation under real-world field conditions is needed . A significant portion of the studies have been conducted in laboratories or greenhouses, where variables are tightly controlled. To ensure that the formulations perform consistently across different soil types, climates, and management systems, large-scale trials over multiple growing seasons are required.
Environmental and food safety are also a concern . When introducing nanoparticles into agricultural ecosystems, it is essential to understand what happens to them in the medium and long term: whether they accumulate in the soil, leach into groundwater, enter the food chain, or remain in the harvested product and at what levels. All of this requires rigorous risk assessments and clear regulatory frameworks.
Another bottleneck is the cost and scalability of production . The synthesis of nanomaterials and encapsulation processes require advanced technology, and even with low doses, reducing manufacturing costs is necessary to supply large agricultural areas. Some nanofertilizers, such as nano-urea or nano-Zn, are already produced industrially, but complex formulations that include active microorganisms continue to face stability challenges during storage and transport.
Finally, there is the human factor: introducing these products requires technical training for agronomists, consultants, and farmers . It is essential to know how to store them, how to apply them, which other products they are compatible with, and how to integrate them into existing fertilization programs. Without this knowledge, there is a risk of misuse or unrealistic expectations.
The future of nanobiofertilizers and their connection to other trends
Looking ahead, everything indicates that nanobiofertilizers will be a key component of next-generation agriculture , integrated with digitalization, precision farming, and the growing commitment to organic and biological solutions. This is not a passing fad, but a profound shift in how we understand plant nutrition.
One of the most interesting lines of research is the development of multifunctional "smart" fertilizers , which combine slow-release nutrients, phosphorus-solubilizing microorganisms, biocontrol agents, and, in some cases, chemical markers to monitor their movement within the plant, all in a single product. These markers will allow researchers to track nanoparticles through plant tissues and better understand their mechanism of action.
Nano-biofertilizers are also a perfect fit for precision agriculture and digitalization . Platforms, sensors, drones, and artificial intelligence are already being used to determine when and how much fertilizer to apply. Integrating nano-bio products into these systems will make it possible to further refine dosages, reduce costs, and improve profitability per hectare.
Trade fairs and industry events, such as FIMA, are becoming showcases where these technologies move beyond theory and become real solutions . Organic and biological fertilizer manufacturers, nano-urea developers, producers of next-generation CRF (combined fertilizers), and digital agriculture companies converge there, creating a technological ecosystem very different from that of just a decade ago.
If production costs can be reduced, the stability of biological formulations improved, and regulatory gaps closed using sound scientific criteria, nanobiofertilizers have the potential to increase yields, reduce dependence on traditional chemical fertilizers, and minimize environmental impacts . All of this positions them as a strategic tool for ensuring food security and sustainability in the coming decades.
The emergence of nanobiofertilizers is reshaping the landscape of plant nutrition: the union of nanotechnology, biology and precision agriculture allows for better crop nutrition, soil regeneration and reduced emissions , responding to current economic and environmental pressures and opening the door to much more efficient, cleaner fertilization aligned with the challenges of the modern agri-food sector.
