The science of microorganisms transforming coffee production, one sip at a time.
On the slopes of Babahoyo, Ecuador, a silent revolution is underway in the Caturra Rojo coffee plantations. As producers face the constant challenge of improving yields without increasing costs or environmental damage, science offers a solution that seems straight out of a biotechnology laboratory: nitrogen-fixing beneficial microorganisms.
These beneficial bacteria, applied as a complement to traditional chemical fertilization, are demonstrating they can transform the productivity of coffee plantations in a natural and sustainable way.
This article explores the fascinating findings of Ecuadorian research that could forever change how we cultivate one of the world's most prized beverages.
Coffee represents one of the most important crops in the Ecuadorian economy. According to data recorded by COFENAC, it is planted in 23 of the 24 existing provinces, in approximately 199,215 hectares, of which 136,385 hectares correspond to arabica coffee and 62,830 hectares to robusta coffee 1 . The provinces of greatest coffee importance are: Los Ríos, Manabí, Loja, El Oro and the Amazonian provinces 2 .
Total coffee cultivation area in Ecuador
Average yield for arabica coffee
Despite this extension, the current average yield is only 5.1 quintals of gold coffee per hectare for arabica and 5.5 quintals for robusta 1 2 . One of the main problems of coffee cultivation in the country is precisely this low yield on producing farms, much of which is due to producers not investing to improve the crop, in most cases dedicating themselves only to harvesting 1 .
In general, tropical soils are deficient especially in organic matter content and consequently nitrogen deficiencies are observed 1 . Despite this knowledge, many coffee producers do not use fertilization practices and other amendments to improve crop nutrition, creating a vicious cycle of low productivity.
Biological nitrogen fixation is a fundamental process for life on our planet that involves the transformation of relatively non-reactive atmospheric N₂ into more reactive compounds such as nitrates, nitrites or ammonia 9 . These reactive forms are suitable for crops and favor their growth, while nitrogen deficiency prevents healthy plant development 9 .
Chemically, nitrogen fixation consists of splitting the triple bond of N₂ and reducing it to ammonia (NH₃) or ammonium (NH₄⁺) 9 . About 90% of natural fixation on our planet is biotic and occurs thanks to soil microorganisms 9 .
Symbiotic bacteria forming nodules on legume roots
Free-living bacteria that associate with plant roots
Aerobic free-living soil bacteria fixing atmospheric nitrogen
Some of the best-known bacteria for this capacity include Rhizobium, Frankia, Azospirillum, Azoarcus, Herbaspirillum, Cyanobacteria, Rhodobacter and Klebsiella, among others 9 . These nitrogen-fixing bacteria synthesize the nitrogenase enzyme, responsible for biological fixation 9 .
The importance of these bacteria lies in that they provide crops with the ready-to-use nitrogen they need as part of chlorophyll molecules, fundamental for photosynthesis 9 . Without this process, plants could not transform light energy into chemical energy, meaning they could not feed properly.
The study was conducted on the grounds of the experimental farm of the Faculty of Agricultural Sciences of the Technical University of Babahoyo, located at Km. 7.5 via Montalvo 2 . The researchers established a randomized complete block design with ten treatments and three replications in plots of twenty-five plants 3 4 .
For statistical analysis of results and comparison of means, the Tukey test at 95% confidence was used 3 .
Confidence level for statistical significance
The research compared different combinations of microorganisms and fertilizers, including:
The chemical fertilization program used as a complement in some treatments consisted of: 160 kg N, 60 kg P, 75 kg K, 30 kg S, 20 kg Mg, 0.4 kg B, 0.2 kg Zn per hectare 3 4 .
The results of the experiment demonstrated that biofertilizers significantly influenced the development and yield of the coffee crop, producing notable increases compared to the control 3 4 .
The analysis of variance determined high statistical significance between treatments, with a coefficient of variation of 32.93% 1 . The application of Micro-Asp (Azospirillium brasilense) at a dose of 6 L/ha in combination with the fertilization program based on soil analysis achieved the highest yield: 1118.75 kg/ha of gold coffee 3 4 .
This result was 4.29 times higher than the control without product application, which only reached 260.7 kg/ha of gold coffee 3 4 .
Micro-Asp 6 L/ha + Fertilization Program
Higher than control
No product application
For comparison
| Nutrient | Amount (kg/ha) |
|---|---|
| Nitrogen (N) | 160 |
| Phosphorus (P) | 60 |
| Potassium (K) | 75 |
| Sulfur (S) | 30 |
| Magnesium (Mg) | 20 |
| Boron (B) | 0.4 |
| Zinc (Zn) | 0.2 |
The genus Azospirillum belongs to a group of Gram-negative bacteria that not only fix nitrogen but also produce phytohormones such as auxins, gibberellins and cytokinins, in addition to producing siderophores and bacteriocins 1 . Azospirillum is a frequent inhabitant of the rhizosphere of a wide variety of plants and is found in different climatic regions of the world 1 .
For its part, Azotobacter is a genus of bacteria that can produce large amounts of capsular slime 1 . It is a free aerobic microbe that lives in soil and fixes atmospheric nitrogen 1 . Azotobacter bacteria are capable of fixing approximately 20 mg N/g of sugar in cultivation or pure in a nitrogen-free medium, being a source to obtain a biofertilizer 1 .
These high biotechnology microorganisms not only fix nitrogen but also increase cation exchange capacity, improve soil structure, provide nitrogen-fixing bacteria to the soil, also decrease the incidence of pests and diseases in crops, reduce pesticide application, decrease chemical fertilizer application 1 .
The findings of this research have profound implications for the sustainability of coffee farming in Ecuador and other regions with similar conditions. The application of nitrogen-fixing microorganisms as a complement to chemical fertilization represents an economic and ecological alternative to improve coffee yields.
Medium-term savings on fertilization inputs for producers
Decreased environmental footprint of cultivation practices
Enhanced soil fertility and structure over time
Significant yield improvements per hectare
Adaptable to different production contexts from small to large farms
Promotion of environmentally friendly agricultural methods
The use of these biofertilizers could mean a paradigm shift in the nutritional management of coffee, allowing producers to adopt more sustainable practices while improving their economic returns.
Furthermore, this technology is scalable and adaptable to different productive contexts, from small producers to large coffee farms.
The research conducted in Babahoyo with nitrogen-fixing microorganisms in Caturra Rojo coffee variety demonstrates the enormous potential of biofertilization as a complement to traditional chemical fertilization.
Gold coffee yield with Azospirillum brasilense + chemical fertilization
The increase of 1118.75 kg/ha of gold coffee obtained with the application of Azospirillum brasilense plus chemical fertilization, compared to 260.7 kg/ha of the control, evidences that we are facing a technology capable of revolutionizing coffee farming.
These findings open a door towards a more sustainable and profitable coffee production, where science and nature collaborate to overcome the challenges of modern agriculture. Nitrogen-fixing microorganisms, those small giants invisible to the naked eye, are emerging as indispensable allies for the future of Ecuadorian coffee.