Everything begins and ends in the soil: there the seed germinates, the plant is nourished by the soil microbiology And, when life completes its cycle, matter decomposes to nourish that same environment again. Therefore, discussing its state is not a whim; it is discussing the real basis of our food securityDepleted, eroded, or polluted soil ceases to effectively support life, resulting in less food, poorer quality food, and more fragile ecosystems.
For years, World Soil Day has been celebrated every December 5th to remind us that soil health is intimately linked to water, climate, and production systems. The message is clear: if we aspire to sustainable agriculture and healthy diets, we need conserve and regenerate the soilnot to exploit it at any cost. The urgency is not rhetorical: nutrient loss, erosion, and compaction are taking their toll worldwide.
What do we mean by healthy soil?
Healthy soil functions as a living and complex ecosystem, where organic matter, minerals, air, water, roots, insects, and a vast microbial community coexist. This balance ensures that there is soil structure and porosity and biological activity so that the plants obtain nutrients, oxygen, water and physical supportWhen that mechanism fails, the productivity and quality of the crops suffer.
The importance is overwhelming: according to the FAO, around 95% of food The food we consume depends directly or indirectly on the soil. It's not just a matter of quantity; it's also about nutritional quality. In fact, 15 of the 18 essential chemical elements for plant growth come from the soil itself, demonstrating that its fertility determines the micronutrient density in the food we put on our plates. That's why it's crucial fertilize the soil Correctly.
Furthermore, soil is a very slow-forming resource. It is estimated that up to 1.000 years to form one centimeterWhereas mismanagement can wipe out that layer in just one campaign. In practical terms, it is finite on a human timescale: what we lose today will take generations to recover.
The nutritional reality is also a concern. The loss of nutrients in agricultural soils has been linked to declines in vitamins and minerals in food over the last few decades, and globally, more than 2.000 million people They suffer from micronutrient deficiencies, the so-called hidden hunger, difficult to detect but with profound impacts on health. Furthermore, soil contamination Microplastics and other waste exacerbate these problems.
Why soil supports food security
If we aspire to meet the projected demand for the coming decades, we must produce more and better without depleting the productive base. According to international estimates, by 2050 agricultural production will need to increase significantly, but this will only be possible with sustainable land management and with efficient use of inputs: applying just what is necessary, at the right time and with practices that bring life back to the land.
In that line, the minimum tillage, crop rotation, and maintenance of plant cover Crop rotation and the addition of organic matter are proven tools. Rotation disrupts pest cycles and balances the ecosystem. nutrient extractionsCover crops reduce erosion and evaporation, conservation tillage protects soil structure and carbon, and organic fertilizers feed the biota that makes fertility possible.
It's not just about maintaining yields; we're also talking about quality. Soils that retain good structure and high biological activity buffer against sudden temperature changes, retain moisture better, and provide more balanced nutrition to plants. Healthy crops, healthy soils, healthier diets: that chain is as simple as it is powerful. Water retention It is a key factor in that damping capacity.
It is worth remembering that only around the 7,5% of the earth's surface It is arable. And yet, soil is often considered limitless. The combination of production pressure, poor practices, and extreme weather events explains why today a third of the world's soil is degraded.
Soil microorganisms: invisible allies
Much of the magic of soil happens at a microscopic scale. In every centimeter, millions of bacteria and fungi can coexist, transforming organic matter, releasing nutrients, and strengthening plant defenses. When this network is active, the soil structure improves, water availability increases, and the rhizosphere becomes an effective barrier against pests and diseases. soil pathogensFurthermore, visible organisms such as the Earthworms that contribute to the decomposition and movement of organic matter.
Plant growth-promoting bacteria (PGPR)
Plant growth-promoting rhizobacteria (PGPR), such as species of Pseudomonas y BacillusThey stand out for their multifunctional role. They stimulate growth, increase nutrient availability, and protect the root system. A prime example is Pseudomonas putida, able to solubilize inorganic phosphorus, produce siderophores that facilitate iron assimilation and thus improve the nutritional status of crops.
These bacteria also influence calcium availability, helping to unlock it in the soil complex so it can be absorbed by the plant. Furthermore, they secrete exopolysaccharides (EPS) that promote biofilm formation in the rhizosphere, a biological shield that protects against pathogens. All of this translates into more robust roots and plants with greater resilience.
Beneficial fungi: the case of Trichoderma
Among the beneficial fungi, the genus Trichoderma It is a classic due to its versatility and rapid growth. It takes advantage of decomposing organic matter, adapts to diverse conditions, and exhibits remarkable antagonistic potential against phytopathogenic fungi. Its arsenal ranges from the direct mycoparasitism even competition for space and nutrients.
Trichoderma can inhibit pathogens through antibiosis (the release of compounds with antimicrobial activity) and, furthermore, activate systemic resistance in the plant, strengthening its own defenses. For this reason, it is considered one of the best biocontrol agents currently available, key to reducing agricultural losses without relying exclusively on [other methods]. chemical inputs.
Soil and climate change: a two-way relationship
Healthy soils not only ensure production, but they are also a key player in climate. Soil constitutes the largest terrestrial reservoir of organic carbon, storing more carbon than vegetation and the atmosphere combined. When soil is degraded, this carbon is released and fuels global warming; when managed well, the soil... retains carbon and contributes to mitigating climate change.
The other side of the coin is the impact of climate on the soil itself. Torrential rains, prolonged heat waves, or widespread temperature increases alter the soil structure, accelerate the mineralization of organic matter, and multiply erosion processes. Depleted soil also loses its capacity to... absorb CO2closing a vicious circle that should be broken as soon as possible.
The figures speak for themselves: billions of tons of fertile soil are lost to erosion every year, with estimates of around 24.000 million tons per year on a global scale. This loss is progressing at a much faster rate than natural regeneration, which reduces productivity, impoverishes food, and makes the restoration of ecosystem services more expensive.
Europe gets to work
In Europe, the threats largely stem from intensive agriculture, deforestation, and urbanization. It is estimated that between 60% and 70% of the soils Soils in the EU present health problems, with a cost of around €50.000 billion per year. Erosion, compaction, pollution, and nutrient depletion are the most frequently cited challenges in the diagnosis.
The political response has taken important steps. The EU has integrated soil health into its Green Deal and has a Soil Strategy for 2030, with clear links to the CAP, the Water Framework Directive, the Habitats Directive, and the Environmental Liability Directive. The aim is to protect, restore, and monitor soil as a pillar of the European sustainability.
In parallel, the "A Soil Pact for Europe" Mission, framed within Horizon Europe, promotes applied science and practical solutions to achieve healthy soils by 2030. Among its key drivers are more than 100 Living Labs (co-creation and field testing) and Lighthouses (large-scale demonstrations), which facilitate the transition from theory to practice with farmers, technicians, researchers, and civil society working together. collaborative manner..
- Citizen involvement: Active participation is sought to accelerate the adoption of solutions.
- Interdisciplinary approach: Agronomy, ecology, economics, and social sciences are combined to integrate answers.
- Adaptability and transferability: methods that can be scaled and replicated in diverse contexts.
Five key reasons to take care of the soil
- It feeds and sustains life: It integrates minerals, water, air and organic matter, and closes the nutrient cycle that allows the production of food, fiber, fuels and compounds of sanitary interest.
- It is finite on a human scale: Its formation is slow and erosion can wipe it out in a single season; bad practices deplete nutrients and accelerate degradation.
- Mitigate climate change: It is a great carbon sink; keeping it healthy helps retain CO2 and reduce greenhouse gas emissions.
- It is a living system: It harbors a huge fraction of the planet's biodiversity —microorganisms, fungi, invertebrates— essential for fertility.
- Managing it well pays off: Sustainable management is much less expensive than restoration when functions have already been lost.
World Soil Day: meaning, objectives and origin
World Soil Day highlights the fact that soil health is closely linked to our nutrition and balanced diets. Campaigns like "Soils, Origin of Food" emphasize that healthy soils produce healthier and more nutritious crops, and that nutrient loss threatens our ability to sustainably grow our food supply. food safety and long-term sustainability.
In another edition, the theme "Caring for soils: measure, monitor, manage" underscored the need for monitoring and data-driven decision-making. It has been celebrated on December 5th since 2014, an initiative of the FAO and the UN, a date that coincides with the birthday of King Bhumibol Adulyadej of Thailand, one of the main proponents of the idea. Its roots, however, go back to 2002, when the IUSS proposed the event within the framework of the Global Soil Partnership. good practice.
Soil governance requires action at all levels, from government to citizens, a principle enshrined in the World Soil Charter and supported by the FAO. It is no surprise that soil is among the priority issues for sustainable development and that its importance has been recognized through initiatives such as the International Year of Soils.
Even digital outreach is adapting to the times: informational pages that promote education and awareness incorporate privacy notices and cookie usage guidelines, while sharing resources, documentaries, and technical materials that help to make better decisions on soil management.
Practices that work on the ground
Conservation tillage minimizes soil profile disturbance, reduces organic matter oxidation, and improves infiltration. This reduces erosion, retains more water, and protects the soil. soil carbonIt's not a one-size-fits-all solution, but it is a trend with positive results in multiple crops and climates. More details on specific techniques can be found in articles about... conservation tillage.
Crop rotation diversifies root systems, disrupts pest and disease cycles, and better distributes nutrient uptake. Combining grasses, legumes, and other plant families promotes resilience and helps prevent yield stagnation. A well-designed rotation optimizes the use of nitrogen and phosphorus and reduces dependence on external inputs.
Vegetation cover, whether spontaneous or sown, protects the surface from the impact of rain, nourishes the biota with living roots, and contributes organic matter as it decomposes. Its presence improves soil structure and water retention capacity, while also buffering the soil. thermal extremes that damage the roots.
Organic fertilization—compost, well-managed manure, or humic amendments—nourishes the soil microbiota and provides organic acids that facilitate nutrient availability. In contrast to the indiscriminate use of synthetic fertilizers, the organic approach rebalances soil chemistry, according to the [organization/source missing]. microbial activity and improves the physical quality of the arable land. A good practice is to integrate systems such as the vermicompost on the farm to obtain high-quality fertilizers.
Agroforestry integrates trees and crops or pastures to provide shade, diversify income, sequester carbon, and contribute leaf litter that enriches the soil. This combination mitigates erosion, increases organic matter, and generates synergies that translate into productive resilience facing droughts and storms.
Clean energy and co-benefits: biodigesters on the farm
An innovative lever is biogas from livestock or agricultural waste. Biodigesters transform this waste into energy and a biofertilizer rich in organic matter and available nutrients. Applied to the soil, this effluent improves water retention, stimulates microbial life, and allows for a reduction in the dose of [unspecified fertilizer]. synthetic fertilizers without penalizing performance.
Closing the loop is not just agronomic: capturing methane that would otherwise go into the atmosphere reduces the farm's climate footprint. Field experiences with commercial biodigesters—for example, installations by companies like Sistema.bio—have documented improvements in fertility, performance increases and more efficient waste management, with fewer odors and less pressure on waterways.
For these solutions to take off, they should be accompanied by training, tailored financing, and technical exchange networks among producers. The integration of biogas, crop rotations, cover crops, and biocontrol creates a coherent agronomic package that improves the soil while providing economic stability to the operation.
Looking at the big picture, soil is much more than an inert support: it's the silent factory that nourishes 95% of our food, a crucial carbon sink, and home to a quarter of biodiversity. Caring for it involves measuring, monitoring, and managing it wisely; it means investing in crop rotations, cover crops, conservation tillage, organic fertilizers, beneficial microbes, and, where appropriate, biodigesters. With policy frameworks like those in Europe, awareness campaigns, and on-the-ground projects, real opportunities are opening up to stop the degradationto restore functions and ensure that future generations have fertile soil and healthy food.
