Soil Ecosystem Services

Last updated: July 26, 2026 Русский Español

When we talk about soils, most people first think of agriculture—that soils provide us with bread, vegetables, and fruits. And indeed, about 98% of humanity's food comes from soil fertility (Valkov et al., 2004). But reducing the importance of soils solely to food production means overlooking the grand role they play in sustaining all life on Earth. In this lecture, we need to understand why soils are so important for society as a whole, how they relate to our well‑being, and why their protection is a matter of human survival.

1. What Are Ecosystem Services?

Before discussing what soils actually do for us, we need to introduce the key concept that underpins this entire lecture—ecosystem services.

Consider a simple fact: when you drink clean tap water, breathe fresh air, or simply enjoy the sight of a green forest, you receive these benefits for free, without thinking about who or how provided them. Ecosystems work for us constantly, without days off or payment. This is precisely what ecosystem services are—the benefits that people obtain from nature.

The most authoritative document on this topic, the Millennium Ecosystem Assessment (2005), defines ecosystem services as the benefits people obtain from ecosystems. Research shows that the value of these services provided by the Earth's ecosystems is estimated at tens of trillions of dollars annually—comparable to the combined gross national product of all countries in the world (Weil and Brady, 2017).

Scientists distinguish four main categories of ecosystem services (Millennium Ecosystem Assessment, 2005; Weil and Brady, 2017):

1. Provisioning services – what we directly obtain from nature: food, fresh water, timber, medicinal plants, fuel. These are the services we usually think of as "benefits from nature".

2. Regulating services – processes that manage the state of the environment: water purification, climate regulation, flood protection, waste decomposition, pest control. We often do not notice these services until they are disrupted.

3. Supporting services – the foundation for all other services: nutrient cycling, soil formation, photosynthesis, primary biomass production. Without these processes, the other services could not exist.

4. Cultural services – intangible benefits: spiritual enrichment, recreation, aesthetic enjoyment, educational and scientific value, cultural heritage.

Soils are one of the most important components of the biosphere, involved in providing all four categories of services. Many of these services are referred to as soil ecosystem functions—the specific roles that soils play in ecosystems and society.

American soil scientist Ray R. Weil and co‑authors identify six key ecological roles that soils perform (Weil and Brady, 2017):

1. Medium for plant growth – soils provide physical support, water, air, and nutrients for plants.

2. Regulation of water regime – soils manage water flow, purification, storage, and distribution.

3. Natural waste recycling system – soils decompose organic residues, returning their elements to the cycle.

4. Habitat for organisms – soils are home to a vast number of living beings.

5. Regulation of atmospheric composition – soils exchange gases with the atmosphere, participating in the carbon cycle.

6. Engineering medium – soils serve as material and foundation for construction.

Note: of these six roles, only the first is directly related to agriculture. The rest are functions that soils perform for the biosphere as a whole. This is what we will study in this lecture.

2. Supporting Services

Supporting services are those ecosystem functions that enable the existence of all other service categories. In a sense, they can be called the "foundation" of ecosystem well‑being. For soils, these fundamental processes are, first, element cycling (biogeochemical cycles), and second, soil formation itself. Without these processes, there would be no fertile lands, no clean water, and no stable climate on the planet.

2.1. Element Cycling

All life on Earth depends on continuous exchange of matter between living organisms, the atmosphere, waters, and the lithosphere. Soil occupies a central place in this exchange: it is simultaneously an accumulator, a transformer, and a source of chemical elements for the biota. This function of soils was noted at the dawn of soil science. V. V. Dokuchaev and his followers emphasised that soil is the result of the interaction between living and non‑living nature, and it is in the soil that the biological (small) and geological (large) cycles converge (Valkov et al., 2004; Mukha et al., 2003).

Geological and Biological Cycles

In nature, two interconnected cycles of matter are distinguished (Mukha et al., 2003).

Geological (large) cycle – the set of processes of crust formation, rock weathering, transport and deposition of mineral masses. It operates on geological time scales (millions of years) and leads to the formation of sedimentary rocks, minerals, and relief.

Biological (small) cycle – the cyclic use of chemical elements by living organisms. Plants extract mineral elements from soil and water, build their tissues from them, and after death return these elements to the soil, where they become available again for new generations of plants (Mukha et al., 2003). The small cycle takes years, decades, and centuries.

Soil is where both cycles meet and interact. It is in the soil that weathering products of rocks (geological cycle) mix with organic matter (biological cycle) to form a unique body—bio‑inert in the terminology of V. I. Vernadsky (Valkov et al., 2004). In soil, there is a constant exchange of elements among solid, liquid, gas, and living phases.

This is particularly evident in the carbon, nitrogen, phosphorus, and sulfur cycles—elements that are the basis of life.

Carbon Cycle

Carbon is the main element of organic matter. Its cycle in nature is largely determined by soil activity. Plants absorb carbon dioxide from the atmosphere, fix carbon through photosynthesis, and build their tissues from it. Part of this carbon returns to the soil with leaf litter, dying roots, and root exudates.

In the soil, organic residues are decomposed by soil microorganisms and invertebrates. As a result of organic carbon mineralisation, CO₂ is released, which returns to the atmosphere (Weil and Brady, 2017; Scheffer et al., 2018). This process is called "soil respiration" and is an important indicator of biological activity.

However, not all carbon entering the soil is rapidly mineralised. Some of it is transformed into stable humus substances that can persist in the soil for hundreds and thousands of years. Thus, soils act as a carbon sink, removing carbon from the atmosphere for long periods. We will discuss this further in the section on regulating services.

It is important to emphasise that the carbon cycle is closely linked to climate: increasing atmospheric CO₂ concentration intensifies the greenhouse effect, while the ability of soils to accumulate carbon can serve as a natural mitigation mechanism (Baldock and Broos, 2012).

Nitrogen Cycle

Nitrogen is one of the key plant nutrients. Most of it in soils is in organic form—in humus, proteins, amino acids, nucleic acids. Only a small fraction of nitrogen is present in mineral forms—nitrates (NO₃⁻) and ammonium (NH₄⁺), which are available to plants (Valkov et al., 2004).

Nitrogen enters the soil through several pathways:

with atmospheric precipitation (fixed nitrogen as ammonia and nitrates);
through biological fixation of atmospheric nitrogen by symbiotic bacteria (rhizobia of legumes) and free‑living nitrogen fixers;
with plant and animal residues;
with mineral fertilisers.

Mineralisation of organic nitrogen occurs through ammonification (conversion of organic compounds to ammonia) and nitrification (oxidation of ammonium to nitrates). Ammonium ions are actively adsorbed by the soil exchange complex, while nitrates are easily leached from the soil, making them available to plants but also posing a risk of groundwater contamination (Valkov et al., 2004).

On the other hand, nitrogen can be lost from the soil to the atmosphere through denitrification—the reduction of nitrates to molecular nitrogen, which occurs under anaerobic conditions. Thus, soil is not only a source but also a regulator of atmospheric nitrogen content.

The linkage between carbon and nitrogen cycles is expressed through the C:N ratio in organic matter. The narrower this ratio (i.e., the more nitrogen relative to carbon), the faster mineralisation proceeds and the more nitrogen is released for plants. On average, the C:N ratio for soil organic matter is about 10–12:1 (Baldock and Broos, 2012; Weil and Brady, 2017).

Phosphorus Cycle

Phosphorus is another critical element for all living organisms, present in ATP, nucleic acids, and membrane phospholipids. Unlike carbon and nitrogen, there is no atmospheric phase for phosphorus; its cycle is mainly confined to the lithosphere and biosphere.

The main source of phosphorus in soils is the minerals apatite and phosphorite contained in rocks. Upon weathering, they release phosphorus as orthophosphate ions (H₂PO₄⁻, HPO₄²⁻). However, the solubility of these ions is low, and most phosphorus in soil is in the form of sparingly soluble salts—calcium phosphates in alkaline soils and iron and aluminium phosphates in acidic soils (Valkov et al., 2004).

Phosphorus is actively taken up by plants and accumulates in the upper, humus‑rich horizons of soils. In organic form, it is represented by phytin, nucleic acids, and phospholipids. Mineralisation of organic phosphorus occurs with the participation of enzymes—phosphatases secreted by microorganisms and plant roots (Valkov et al., 2004). Thus, the phosphorus cycle is strongly dependent on soil biological activity.

Since phosphorus is hardly transported by water in soluble form over long distances, its reserves in soil can be quickly depleted under intensive agriculture unless replenished by fertilisers. Soils therefore serve as the main reservoir of phosphorus for terrestrial ecosystems.

Sulfur Cycle

Sulfur is another essential element, found in amino acids (cysteine, methionine), vitamins, and coenzymes. The main forms of sulfur in soils are organic (in proteins, amino acids) and mineral (sulphates SO₄²⁻, sulphides, elemental sulfur). Sulfur enters through atmospheric precipitation, weathering of sulphide minerals, and decomposition of organic residues (Baldock and Broos, 2012; Weil and Brady, 2017).

An important feature of the sulfur cycle is its dual nature: under oxidising conditions, sulphates predominate, which are readily soluble and available to plants; under reducing conditions (in waterlogged soils), sulphides dominate, which can be toxic and contribute to the formation of hydrogen sulphide.

Soils regulate not only sulfur availability to plants but also its release into the atmosphere as volatile compounds (hydrogen sulphide, dimethyl sulphide), affecting precipitation acidity and climatic processes (Baldock and Broos, 2012).

Integration of Cycles in the Soil System

The peculiarity of soil as a natural body is that all these cycles occur simultaneously and interconnectedly in the same space—in pores, on the surface of colloidal particles, in biofilms (Weil and Brady, 2017). For example, decomposition of organic matter (carbon cycle) simultaneously releases nitrogen, phosphorus, and sulfur into plant‑available forms. Microorganisms involved in mineralisation use carbon as an energy source and need nitrogen, phosphorus, and sulfur for building their bodies. Thus, the ratios of these elements in the substrate determine the intensity and direction of processes.

It is in the soil that a dynamic equilibrium is maintained between the immobilisation of elements in organic matter and their release into mineral forms. Thanks to this, plants receive nutrients not episodically but continuously, in a rhythm matching their physiological needs. This ability of soils to self‑regulate element cycling is one of the most important supporting ecosystem services.

2.2. Soil Formation

The second fundamental supporting service is the continuous creation and renewal of the soil itself. Soil formation is a process that goes on constantly, but so slowly that its results become noticeable only on the scale of centuries and millennia. This slowness makes soil practically a non‑renewable resource on the human timescale.

Factors of Soil Formation

The foundation of the modern understanding of soil formation was laid by V. V. Dokuchaev and developed by H. Jenny (Jenny, 1941). According to their concept, soil is a function of five factors:

1. Parent material – the substrate from which soil forms. This can be unconsolidated sediment (alluvium, loess, moraine) or weathering crust of hard rocks. The composition of the parent material determines the mineralogical and granulometric composition of the future soil and its chemical properties.

2. Climate – determines the water and temperature regimes, which in turn affect the rate of chemical reactions, biological activity, and the direction of soil processes. For example, in humid conditions, leaching and podzolisation prevail, while in arid conditions, carbonate accumulation and salinisation dominate (Scheffer et al., 2018).

3. Organisms (vegetation, animals, microorganisms) – the main biotic factor. Plants supply organic matter; root systems loosen and chemically transform the rock; microorganisms and soil animals participate in organic matter processing, humus formation, and structure creation (Weil and Brady, 2017).

4. Relief – redistributes moisture and heat in the landscape. On slopes, water runs off, causing erosion and reducing leaching; in depressions, water stagnates, creating hydromorphic conditions (Scheffer et al., 2018).

5. Time – the duration of the other factors' action. Soil formation is a very slow process; thousands or tens of thousands of years are required to form a differentiated profile.

In modern interpretations, especially with the concept of the Anthropocene, human activity is added to these factors, as humans increasingly alter soils through agriculture, melioration, pollution, and urbanisation (Richter and Tugel, 2012). Thus, the soil formation formula becomes (Scheffer et al., 2018; Richter and Tugel, 2012):

\text{Soil} = f(\text{parent material}, \text{climate}, \text{relief}, \text{organisms}, \text{humans}, \text{time})

Elementary Soil Processes

The interaction of these factors triggers a series of elementary soil processes, which can be grouped into four categories (after Simonson, 1959, cited in Richter and Tugel, 2012):

Additions – input into the soil of organic material (litter, root exudates), mineral particles (dust, sediments), and solutions;
Losses – removal of substances from the soil by erosion, leaching, mineralisation, and gas emissions;
Transformations – chemical and biological changes of matter within the soil: mineral destruction, synthesis of secondary minerals, humification, oxidation‑reduction;
Translocations – movement of substances within the soil profile with water (eluviation, illuviation), bioturbation, cryoturbation, mixing.

These processes occur simultaneously and with different intensities in different horizons. Their result is the formation of the soil profile—a sequence of genetic horizons differing in colour, structure, chemical composition, and other characteristics (Valkov et al., 2004; Mukha et al., 2003).

Organic Matter and Humification

A special place in soil formation is occupied by the transformation of plant and animal residues into humus. Humification is a complex biochemical process resulting in the formation of specific organic compounds unique to soils: humic acids, fulvic acids, and humins (Valkov et al., 2004). Humus gives soil its characteristic dark colour, determines its cation exchange capacity, water‑holding capacity, and structural state.

Modern theories of humification (M. M. Kononova, L. N. Alexandrova, D. S. Orlov) distinguish several stages of this process (Valkov et al., 2004):

1. Decomposition of primary organic compounds (cellulose, lignin, proteins) by microbial enzymes;

2. Oxidative transformation of decomposition products to form reactive aromatic structures;

3. Condensation of these structures with amino acids and other nitrogenous components into high‑molecular humic acids;

4. Gradual mineralisation of part of the humic substances and simultaneous renewal through new inputs.

Humic substances play a central role in all other supporting and regulating functions of soils: they improve structure, increase water‑holding capacity, provide cation exchange capacity, serve as a source of slowly released nutrients, and store carbon (Baldock and Broos, 2012; Weil and Brady, 2017).

Soil Formation as an Ecosystem Service

From the perspective of ecosystem services, soil formation is the process of creating and maintaining a habitat for all terrestrial organisms. Without it, there would be no fertile soils, and hence no sustainable vegetation or the entire food chain, including humans.

However, soil formation is extremely slow. According to various estimates, it takes 100 to 400 years to form 1 cm of humus horizon in temperate climates (Scheffer et al., 2018). This means that soil losses due to erosion or unsustainable use cannot be compensated naturally in the foreseeable future. Soil is therefore a non‑renewable resource on the human timescale.

This is precisely why maintaining the natural course of soil formation is a key task of sustainable land use. In agriculture, humans can accelerate some stages of soil formation (e.g., by adding organic matter), but cannot replace the entire complex of processes occurring in natural soil. Understanding this limitation underpins modern approaches to soil health and protection.

Anthropogenic Influence on Soil Formation

In recent centuries, humans have become a powerful factor in soil formation. Ploughing, fertilisation and amelioration, land reclamation, urbanisation, and pollution all change the rate and direction of soil‑forming processes (Richter and Tugel, 2012). As a result, anthropogenically transformed soils (agrozems, urbanised soils, reclaimed soils) are formed, with their own specific horizons and properties (Mukha et al., 2003).

On the one hand, agricultural use can improve some soil properties (e.g., increase humus content with proper management). On the other hand, it often leads to degradation: loss of organic matter, compaction, salinisation, erosion. Globally, anthropogenic soil degradation today exceeds natural soil formation, posing a threat to food security and ecosystem stability (Richter and Tugel, 2012; Weil and Brady, 2017).

Thus, the supporting service of soil formation now requires conscious management: we must not only use fertility but also support the processes of its restoration, otherwise we risk losing this priceless natural asset forever.

In the next section, we will move to regulating services—how soils manage flows of water, carbon, pollutants, and thereby maintain the environmental quality that directly affects human and ecosystem health.

3. Regulating Services

Regulating services are those processes that soils perform to manage flows of matter and energy in the environment. Unlike supporting services (which create the foundation for life) or provisioning services (which give us specific products), regulating services are the natural work of soils in maintaining ecosystem homeostasis and habitat quality. We often do not notice them until they are disrupted. But these functions make possible the existence of human settlements, clean water, and stable climate.

We will consider four main regulating services that soils perform: water filtration and purification, chemical and biological buffering, carbon sequestration, and hydrological regulation.

3.1. Filtration and Purification of Water

This is perhaps the most intuitively understood regulating function of soils. Every time it rains, snow melts, or we water our gardens, water percolates through the soil. In this process, it undergoes profound purification. Soil is a natural, self‑renewing filter that has been working without our involvement for millions of years.

Filtration Mechanisms

Water purification in soil occurs through a combination of physical, chemical, and biological mechanisms (Valkov et al., 2004; Weil and Brady, 2017):

1. Mechanical filtration. Soil acts as a "sieve": large pores retain suspended particles, sand grains, and organic residues, while smaller pores retain finer colloidal particles. This process is called mechanical absorption capacity. It is particularly evident in river floodplains during floods, when water leaves a thin layer of alluvium on the soil surface (Valkov et al., 2004).

2. Physical adsorption. Soil colloids (clay minerals and humus) have a huge specific surface area. On the surface of these colloids, not only ions but also whole molecules, including organic pollutants, can be retained. Surfactants concentrate at the phase interface, being removed from the solution (Valkov et al., 2004).

3. Chemical precipitation. In the soil solution, chemical reactions can occur leading to the formation of sparingly soluble compounds that precipitate. For example, phosphates bind with calcium, iron, or aluminium ions; heavy metals form insoluble hydroxides or carbonates (Valkov et al., 2004).

4. Ion exchange. The soil exchange complex can exchange cations with the solution, replacing them with others. Thus, as water percolates through soil, excess cations (e.g., heavy metals) are removed, while exchangeable cations (calcium, magnesium, potassium) enter the solution. This regulates the salt composition of water (Valkov et al., 2004).

5. Biological purification. Soil microorganisms and plant roots actively absorb and transform various organic and inorganic substances. Bacteria and fungi break down complex organic molecules (pesticides, petroleum products, phenols) into simple non‑toxic compounds. This process is called biological absorption capacity and is highly selective—different microbial species specialise on different pollutants (Valkov et al., 2004; Weil and Brady, 2017).

Importance for Water Quality

Thanks to these mechanisms, water that passes through the soil becomes significantly cleaner. This process enables the use of groundwater as a source of drinking water (Weil and Brady, 2017). Ancient peoples already noticed that water filtered through the earth becomes fresh: the Roman poet Lucretius wrote that sea water, passing through the "thickness of the earth", leaves behind "bitter parts" and becomes sweet (Valkov et al., 2004).

The filtering function of soils is especially important in wastewater treatment systems. Artificial filtration fields used in small settlements are essentially soil systems through which wastewater is passed. In the soil, biological purification occurs through the work of microorganisms and physicochemical processes (Valkov et al., 2004).

However, the filtration capacity of soils is not unlimited. When permissible loads are exceeded (e.g., through excessive fertiliser or pollutant application), the soil fails to cope, and contaminants reach groundwater. Therefore, protecting soils from pollution simultaneously protects water resources.

Filtration and Erosion

Erosion—the destruction of the soil cover by water or wind—sharply reduces filtration capacity. Water no longer infiltrates deeply but runs off over the surface, carrying soil particles away. This creates a vicious circle: erosion worsens filtration, and reduced filtration intensifies erosion.

Therefore, protecting soils from erosion is also protecting water resources from pollution by suspended solids and chemicals (Richter and Tugel, 2012; Weil and Brady, 2017).

3.2. Chemical and Biological Buffering

Buffering is the ability of a system to resist changes in its properties under external impacts. Soils possess a unique buffering capacity that manifests at several levels.

Chemical Buffering (with respect to pH)

Soil contains many substances capable of binding or neutralising hydrogen ions (acids) and hydroxide ions (alkalis). This is seen in the ability of soil to keep pH within relatively stable limits despite inputs of acid rain, fertilisers, or other substances (Valkov et al., 2004; Weil and Brady, 2017).

The main components providing pH buffering are:

Calcium and magnesium carbonates (CaCO₃, MgCO₃) – strong buffers acting in alkaline and neutral ranges. They neutralise acids with CO₂ release:

$$CaCO_3 + 2H^+ \rightarrow Ca^{2+} + H_2O + CO_2$$

Thanks to this, carbonate‑rich soils are resistant to acidification (Valkov et al., 2004).

Humic substances – contain carboxyl (-COOH) and phenolic (-OH) groups that can dissociate to release H⁺ (in acidic media) or bind H⁺ (in alkaline media). The cation exchange capacity of humus is 400–800 meq/100 g (Valkov et al., 2004), making it a powerful buffer.

Clay minerals – especially layered silicates (montmorillonite, vermiculite), which undergo cation exchange and can bind both H⁺ and basic cations, regulating solution pH.

The buffer capacity of soils depends on their composition. Soils rich in humus and clay minerals (chernozems, soddy soils) have high buffering, whereas sandy soils with low organic matter have low buffering.

Buffering against Pollutants

Soils can bind and inactivate many toxic substances:

Heavy metals (lead, cadmium, copper, zinc) can be strongly adsorbed by organic and clay colloids, becoming less available. This prevents their uptake by plants and leaching to groundwater (Valkov et al., 2004).

Organic pollutants (pesticides, petroleum products, phenols) are adsorbed on organic matter and can be degraded by microorganisms. However, this process may be slow, and some contaminants remain in soil for long periods (Richter and Tugel, 2012).

Biological Buffering

The soil community of organisms can adapt to changing conditions. Under moderate pollution or pH changes, some microbial species die off, but others, more tolerant, take their place, continuing the functions of decomposition and transformation of substances. This makes the soil ecosystem more resilient to stress than many other ecosystems (Weil and Brady, 2017).

However, biological buffering has its limits. Under severe or prolonged impact, the microbial community structure can collapse, and the soil loses its self‑purification functions. This is one sign of soil degradation.

3.3. Carbon Sequestration (Storage)

This service, as we briefly mentioned, has gained particular relevance today due to global climate change. Soils are the largest terrestrial reservoir of organic carbon, and changes in its stocks can significantly affect atmospheric CO₂ concentration (Baldock and Broos, 2012).

Scale of Carbon Storage in Soils

Estimates indicate that the world's soils contain 1200 to 1550 Pg of carbon in the upper metre and 2300 to 2450 Pg in the layer up to 2–3 m (Baldock and Broos, 2012). These figures are impressive: soils hold 2–3 times more carbon than the atmosphere (about 760 Pg) and 4–5 times more than plant biomass (about 560 Pg).

Carbon enters the soil mainly through plant residues: fallen leaves, dead roots, root exudates. During decomposition by microorganisms, most of this carbon returns to the atmosphere as CO₂ ("soil respiration"). But some organic carbon becomes "entombed" in the soil for long periods—this is called stable organic carbon (Baldock and Broos, 2012).

Forms and Stability of Soil Carbon

Organic carbon in soils can be divided into several pools according to turnover time (Baldock and Broos, 2012; Weil and Brady, 2017):

Labile carbon (fast‑turnover) – simple sugars, organic acids, fresh plant residues. Half‑life ranges from days to several years. This pool is most active in microbial nutrition and determines current soil biological activity.

Moderately stable carbon – products of partial decomposition, humic substances of medium condensation. Turnover time – decades. This pool is important for maintaining soil structure and water‑physical properties.

Stable (recalcitrant) carbon – highly condensed humic substances, as well as black carbon (charcoal, soot, graphite). Turnover time – hundreds to thousands of years. Black carbon is particularly resistant to decomposition; it is formed during fires and can account for up to 60% of organic carbon in some soils (Baldock and Broos, 2012).

Mechanisms of Carbon Stabilisation in Soils

Why does some organic carbon not decompose but persist in soil for centuries? Scientists distinguish three main stabilisation mechanisms (Baldock and Broos, 2012; Weil and Brady, 2017):

1. Chemical recalcitrance – some organic structures (lignin, waxes, resins, black carbon) are very resistant to enzymatic decomposition due to the complexity of their bonds. However, this mechanism is often overestimated: many "recalcitrant" substances are still degraded by microorganisms given time and suitable conditions.

2. Physical protection – organic matter can be "hidden" inside aggregates (micro‑ and macroaggregates), in fine pores where microorganisms or their enzymes cannot penetrate. According to the hierarchical model of soil structure (Tisdall and Oades, 1982), small aggregates (< 20 µm) form from organic and inorganic colloids, and organic matter inside them is practically inaccessible to decomposition (Ghezzehei, 2012).

3. Chemical binding with minerals – organic substances can adsorb onto the surface of clay particles, iron and aluminium oxides, forming strong organo‑mineral complexes. These complexes protect organic matter from enzymatic attack. This stabilisation is especially pronounced in soils rich in amorphous Al and Fe oxides (e.g., Andisols), where organic carbon can persist for very long periods (Baldock and Broos, 2012).

Significance for Climate Regulation

Managing soil carbon stocks is one of the key approaches to combating climate change. If soil organic carbon were increased by 0.4% annually, it could offset a significant portion of anthropogenic CO₂ emissions (the "4 per 1000" initiative). However, it is important to remember that the potential of soils to accumulate carbon is limited: for each soil type there is a carbon saturation limit determined by its physical and chemical properties (Baldock and Broos, 2012).

Thus, carbon sequestration is not an infinite resource, but a very important regulating mechanism. Proper land use (minimising tillage, applying organic fertilisers, maintaining plant cover) can significantly increase soil carbon content and thereby mitigate climate change.

3.4. Hydrological Regulation

This service is manifested in the ability of soils to manage water flows in landscapes—from the moment precipitation falls until it enters rivers and groundwater. Soils determine how much water infiltrates, how much is stored, how much evaporates, and how much becomes surface runoff. This affects plant water supply, flood risk, and groundwater recharge.

Infiltration and Filtration

Infiltration is the process of water entering the soil from the surface. It depends on soil permeability—the ability to transmit water through its pore system (Valkov et al., 2004). Permeability depends on:

Granulometric composition: sandy soils have high permeability (up to 1000 mm/h and above), clayey soils have low (less than 30 mm/h). Loamy soils are intermediate (Valkov et al., 2004).
Structural condition: well‑aggregated soils (granular, crumb) have a system of large pores through which water quickly moves downward; structureless soils (massive, compact) have poor permeability and often develop surface crusts hindering infiltration (Ghezzehei, 2012; Weil and Brady, 2017).
Moisture content: wet soil transmits water more slowly than dry soil because some pores are already filled with water.

High permeability is beneficial for ecosystems: water infiltrates quickly, recharging groundwater and preventing surface runoff. However, if the soil is too sandy, water may percolate too deeply and become unavailable to plants.

Filtration is the movement of water within the soil profile after infiltration is complete, when all pores are filled with water. Filtration determines how much water reaches the lower horizons and, ultimately, groundwater (Valkov et al., 2004). Under natural conditions, a significant portion of precipitation filters through the soil, recharging aquifers.

Water‑Holding Capacity

Soil can retain a certain amount of water, which can then be used by plants. This capacity is called water‑holding capacity and is quantitatively expressed through several hydrological constants (Valkov et al., 2004):

Total water‑holding capacity (TWC) – the maximum amount of water that soil can retain when all pores are completely filled. This state corresponds to full saturation, when water begins to drain by gravity.

Field capacity (FC) – the amount of water remaining in the soil after gravitational water has drained. This is the water most available to plants. Field capacity varies from 5–10% in sands to 55% in heavy clays (Valkov et al., 2004).

Wilting point (WP) – the minimum moisture content at which plants still do not wilt. This water is held in the soil with such force that roots cannot extract it. Wilting point depends on colloid content: the more colloids, the higher the wilting point (from 2–3% in sands to 15–20% in clays) (Valkov et al., 2004).

Available water capacity – water in the range between FC and WP. This is the water available to plants and determines their drought resistance (Valkov et al., 2004).

Interestingly, organic matter in soil increases water‑holding capacity. Humus is a hydrophilic colloid capable of absorbing water 15–20 times its own weight (Weil and Brady, 2017). Therefore, humus‑rich soils (chernozems, soddy soils) retain moisture better and withstand dry periods more easily.

Protection against Droughts and Floods

The regulating function of soils in hydrological regimes operates at the landscape level:

Flood protection. Soils with high infiltration capacity quickly absorb rainwater and snowmelt, slowing runoff and reducing flood peaks. Forests and grasslands perform this role particularly well: their soils are well structured and permeated with roots, promoting rapid infiltration. In contrast, disturbed soils (deeply ploughed arable land, compacted urban soils) lose this ability, and water runs off the surface, causing floods (Ghezzehei, 2012).

Drought protection. Soils with high water‑holding capacity store moisture during wet periods and release it to plants during dry periods. Deep, humus‑rich soils can hold enough water to sustain vegetation for several months without rain. This is especially important for forests, perennial pastures, and arid regions (Weil and Brady, 2017).

Capillary Rise and Moisture Redistribution

Another important aspect is the ability of water to rise upward through capillaries from the water table. The height of capillary rise in clayey soils can reach 2–6 metres, while in sandy soils it is only 40–60 cm (Valkov et al., 2004). Capillary‑supported water forms a capillary fringe above the aquifer and serves as a source of moisture for plants during dry periods. However, in arid conditions, capillary rise can lead to salt accumulation in upper horizons if the groundwater level is close to the surface and evaporation is intense.

3.5. Interconnection of Regulating Functions

All the described regulating services are closely interconnected. Water filtration improves groundwater quality and simultaneously promotes leaching of salts from the root zone. Accumulation of organic matter increases water‑holding capacity and aggregation, which in turn enhances infiltration and reduces erosion. And well‑structured soil with high humus content better buffers pH and binds pollutants.

Thus, the regulating services of soils are inextricably linked and reinforce each other. Maintaining or improving one of them usually has positive effects on the others. Conversely, soil degradation (e.g., loss of humus) simultaneously weakens filtration, reduces buffering, decreases carbon sequestration capacity, and disrupts hydrological regimes. This means that sustainable soil management must be holistic, aimed at preserving the entire set of functions, not just individual properties.

In the next section, we will move to provisioning services—those that directly provide us with food, feed, and raw materials. But it is important to remember that these provisioning services are possible only thanks to the supporting and regulating functions we have just examined. Without them, fertility would be short‑lived and agriculture unsustainable.

4. Provisioning Services

Provisioning ecosystem services are the tangible goods that we directly extract from nature. In the case of soils, these services are the most obvious and perhaps the most familiar to our perception. Yet here too, beneath apparent simplicity, lies profound complexity, and the goal of this lecture is to show how exactly soils provide these benefits and why their quality depends on the state of all other ecosystem functions.

4.1. The Basis of Food Production

The main provisioning service of soils is creating conditions for growing plants that serve as food for humans and animals. About 98% of food is obtained by humanity thanks to soil fertility (Valkov et al., 2004; Weil and Brady, 2017). This means that practically all our food—from bread to meat, from vegetables to dairy products—has soil as its ultimate source. Livestock products also depend on soil, because animal feed consists of plants grown on soils (Scheffer et al., 2018).

What exactly does soil provide for food production?

Physical Environment for Roots

For plants, soil is not just a source of nutrition but also support. Root systems anchor in the soil, allowing plants to maintain an upright position, resist winds and precipitation. In addition, soil provides roots with access to water and air, since roots respire by absorbing oxygen from soil pores (Weil and Brady, 2017).

Soil structure, discussed in the supporting services section, plays a decisive role here. Loose, aggregated soil allows roots to penetrate deeply, exploring large volumes to obtain water and nutrients. Conversely, compacted soils with bulk density above 1.4–1.6 g/cm³ become an impassable barrier for the roots of most crop plants (Valkov et al., 2004; Ghezzehei, 2012).

Water Supply to Plants

Soil is the reservoir from which plants draw water throughout the growing season. The ideal state for most crops is when soil pores are filled roughly equally with water and air (about 25% each by volume), corresponding to a moisture content of about 60% of field capacity (Weil and Brady, 2017; Valkov et al., 2004).

It is important to understand that not all water in the soil is available to plants. As mentioned, we distinguish:

Gravitational water – drains quickly downward and is rarely used by plants;
Capillary water – held in capillaries and is the main available form of moisture;
Film (loosely bound) water – available, but its movement is very slow;
Hygroscopic (tightly bound) water – unavailable to plants, as it is held by molecular forces on colloidal particle surfaces (Valkov et al., 2004).

The wilting point (WP) is the critical threshold below which plants can no longer extract water and begin to wilt. It varies among crops and soils (see Table 1 in Valkov et al., 2004). The more colloids (clay, humus) in the soil, the higher the wilting point, but also the higher the field capacity, so the total available water reserve is greater.

Nutrient Elements

Soil is the main source of 14 of the 17 elements required for plant growth (Weil and Brady, 2017). These are macronutrients (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur) and micronutrients (iron, manganese, zinc, copper, molybdenum, boron, chlorine, cobalt, nickel).

According to Valkov et al. (2004), the distribution of elements in forms in soil resembles a person's financial assets (analogy from Weil and Brady, 2017): most elements are "locked" in the structural framework of minerals and organic matter (long‑term investments), a smaller part is in exchangeable form on colloidal particles (short‑term investments), and only a tiny fraction is directly in the soil solution (cash). The task of the soil system is to continually replenish the pool of "cash" (available to roots) from the "short‑term" and "long‑term" reserves.

This is precisely soil fertility—the ability to continuously supply plants with nutrients in the required quantities and proportions (Valkov et al., 2004; Mukha et al., 2003). Fertility is the main thing that distinguishes soil from barren rock. It is not a constant property; it is dynamic, depending on the balance between mineralisation (release of elements from organic matter) and immobilisation (fixation of elements in microbial biomass and humus).

Link between Fertility and Other Soil Functions

The provisioning service of food production is unthinkable without supporting and regulating services. Without element cycling, there would be no nutrients; without buffering, pH would quickly exceed crop tolerance; without water‑holding capacity, plants would die in the first dry spell; without filtration, roots would suffer from toxicants. Thus, fertility is the integrated result of the entire soil system's work.

4.2. Production of Biomass for Non‑food Purposes

Soils are a source not only of food but also of vast amounts of biomass for other human needs (Weil and Brady, 2017; Scheffer et al., 2018).

Fibres

Cotton, flax, hemp, jute—all these fibre crops are obtained from plants grown on soils. Besides food crops, soils are used for producing textiles (cotton is one of the world's major crops by area), ropes, burlap, and technical fabrics. Fibre quality depends not only on plant variety but also on soil properties: adequate moisture, availability of potassium and nitrogen directly affect fibre length and strength (Weil and Brady, 2017).

Timber

Forests are soil ecosystems. Timber remains one of the main construction materials, sources of cellulose, paper, and fuel. Forest growth is largely determined by forest soil quality (water regime, nutrient availability, acidity). Moreover, forests themselves regulate soil processes (Weil and Brady, 2017).

Biofuels and Bioplastics

With technological development and depletion of fossil fuels, soils become sources of raw material for biofuels (ethanol from corn and sugarcane, biodiesel from soy and rapeseed, biogas from crop residues) and biodegradable plastics (from corn starch, plant‑based polymers) (Weil and Brady, 2017). These products can replace non‑renewable resources, but this raises a serious dilemma: use soils for food production or for industrial crops. This is an environmental and ethical challenge already facing the global community.

Medicinal Resources

Many pharmaceuticals have soil origins. Apart from direct use of medicinal plants, most antibiotics (penicillin, tetracycline, streptomycin, erythromycin, and many others) are produced by soil microorganisms—bacteria of the genus Streptomyces, actinomycetes, fungi (Weil and Brady, 2017). These microorganisms produce antibiotics as a defence against competitors in their natural environment, and humans use them to treat infections.

Soils remain the most important source for discovering new bioactive compounds. Every year, new species of microorganisms are discovered in soils that produce previously unknown antibiotics, antitumour agents, and immunomodulators (Weil and Brady, 2017; Valkov et al., 2004). Soil biodiversity is essentially a genetic reserve for future pharmacology.

4.3. Provisioning Services and Human Health

The provisioning function of soils directly affects human health not only through the quantity and quality of food but also through the micronutrient content of food (White, 2006; Weil and Brady, 2017).

Zinc deficiency in soils – a widespread phenomenon (about half of the world's agricultural soils are zinc‑deficient). This leads to zinc deficiency in plants and consequently in human diets, causing immune disorders, stunted growth, skin and hair problems (Weil and Brady, 2017).

Selenium deficiency in soils – leads to diseases such as Keshan disease (heart muscle damage), especially in some regions of China where soils are extremely low in selenium (Weil and Brady, 2017).

Iodine deficiency in soils – causes endemic goitre in humans and animals. Iodine enters plants from soils, and in regions with low soil iodine, people historically suffer from iodine deficiency (Weil and Brady, 2017).

Thus, soils are not only a "factory" of food but also a regulator of food quality, and hence of national health. Agrochemical methods (application of micronutrients, fortified fertilisers) can correct these deficiencies, but the best approach is to preserve and enhance natural fertility through organic matter, which binds and retains micronutrients in plant‑available forms (Weil and Brady, 2017).

4.4. Soil as a Means of Production

In the agricultural context, soil is the main means of production (Mukha et al., 2003). It is simultaneously an object of labour (it is tilled, fertilised, and treated) and an instrument of labour (used as a medium for growing plants). Unlike a machine or tractor, soil does not wear out under proper use; on the contrary, it can improve its properties. However, under improper management, it degrades, and restoration requires enormous costs and time.

Soil is an irreplaceable and non‑renewable resource (Scheffer et al., 2018; Valkov et al., 2004):

Irreplaceable means that no other substrate can replace soil on a planetary scale for food production. Hydroponics and aeroponics can be used locally, but for global feeding of 9 billion people they are unrealistic.
Non‑renewable means that the rates of natural soil formation (1 cm per 100–400 years) are incomparable with the rates of soil loss due to erosion, degradation, and urbanisation (Scheffer et al., 2018). According to FAO estimates, about one‑third of the world's agricultural soils have been lost to erosion and degradation over the past 50 years, and this trend continues (Weil and Brady, 2017).

4.5. Sustainability of Provisioning Services

Provisioning services are the most obvious, but also the most vulnerable. Intensive use can lead to soil depletion if other functions (element cycling, organic matter accumulation, structure maintenance) are not sustained. This is why the concept of sustainable agriculture assumes that yields must be taken within the limits that allow soil to restore fertility (White, 2006; Richter and Tugel, 2012).

Key threats to provisioning services:

Erosion – removes the top, most fertile soil layer, which takes centuries to restore (Weil and Brady, 2017; Scheffer et al., 2018).
Loss of organic matter – due to intensive tillage, monocultures, and lack of organic returns (Baldock and Broos, 2012).
Salinisation – under irrigation in arid conditions (Valkov et al., 2004; Weil and Brady, 2017).
Contamination with heavy metals and pesticides – impairs product quality and reduces biological activity (Valkov et al., 2004).
Compaction – caused by heavy machinery, limiting root penetration and water movement (Ghezzehei, 2012).

Thus, provisioning services are not an autonomous benefit; they depend on supporting and regulating functions. Their preservation requires a holistic approach to soil management that considers all aspects of ecosystem services. This is the subject of the modern concept of soil health, which we will address in the following modules.

5. Cultural Services

We now turn to the last but by no means secondary category of soil ecosystem services—cultural services. Unlike provisioning (food, biomass) and regulating (water purification, carbon storage), cultural services represent intangible benefits that soils provide to people. They concern our perception, our values, our history, and our connection to nature. Often, these services shape a person's sense of belonging to a place, a sense of homeland, and they make soil not just a natural resource but part of the cultural landscape.

5.1. Definition of Cultural Services

According to the Millennium Ecosystem Assessment (2005), cultural services are the non‑material benefits people obtain from ecosystems through spiritual enrichment, cognitive development, recreation, aesthetic experiences, and cultural heritage. Applied to soils, this means that the soil cover influences:

cultural identity and sense of place;
historical memory (archaeological sites, buried horizons);
aesthetic perception of landscapes;
recreational opportunities (gardens, parks, natural areas);
educational and scientific value (studying soils as natural archives).

As Valkov et al. (2004) emphasise, soil is not only a natural body but also "land" in a broader sense—the territory on which human history unfolds, cities are built, and cultural monuments are preserved. In Russian, as in many other languages, there is a distinction between "почва" (soil, solum) and "земля" (land). Land is not just the surface layer; it is landscapes, settlements, fields, forests, water bodies—the entire geographical environment in which humans live (Valkov et al., 2004). And soil is its foundation.

5.2. Historical and Cultural Heritage: Soil as an Archive

One of the most important cultural functions of soils is their role as a natural archive of Earth's and humanity's history. Soil horizons form slowly, and they "record" past events: climate changes, fires, floods, volcanic eruptions, the activity of ancient civilisations.

Archaeological value of soils. Artefacts are preserved in soils—pottery fragments, stone tools, animal bones, charcoal from ancient fires, building remains. Because soils have buffering and sorption properties, they can preserve these objects for millennia. Artefacts are particularly well preserved under anaerobic conditions (peatlands, illuvial horizons) or in dry alkaline soils (e.g., loess deposits) (Valkov et al., 2004; Richter and Tugel, 2012).

Study of buried soils (palaeosols) allows reconstruction of climate changes, past landscapes, and migration routes of peoples. For example, the ratio of humic to fulvic acids in buried soils can indicate vegetation and humidity in different geological eras (Baldock and Broos, 2012). Thus, soils serve as "historical chronicles" that can be read by specialists.

Cultural layers. In cities and ancient settlements, so‑called cultural layers are formed—anthropogenically modified soils and deposits containing residues of human activity. They can reach several metres in thickness and contain information about daily life, technologies, and economies of past epochs. Studying cultural layers is a fundamental method of archaeology (Richter and Tugel, 2012).

Soil as a carrier of identity. Historically, soil quality and use determined the development of civilisations. Numerous examples attest to this: fertile chernozems underpinned the power of agricultural cultures, while soil depletion led to the decline of entire civilisations (e.g., in the Middle East). Therefore, soil is inextricably linked to the history of peoples and cultures.

5.3. Aesthetic Value and Landscape Formation

Soils play a huge role in shaping the external appearance of landscapes—their aesthetics. Soil colours (chernozems, red soils, yellow soils, podzols, grey soils) are not just diagnostic traits but also elements of visual perception of nature. The diversity of soils creates a mosaic of fields, forests, steppes, inspiring artists, poets, and ordinary people admiring the scenery.

Soils also determine the type of vegetation: where forests, where steppes, where meadows. Vegetation, in turn, shapes the landscape's appearance. Thus, soils are the foundation of nature's aesthetic diversity (Weil and Brady, 2017).

In garden and park design, soils are the basis for creating parks, gardens, squares, and flower beds. Soil properties (fertility, structure, water‑holding capacity) directly affect plant selection and landscaping success. Well‑cultivated soil pleases the eye with a riot of colours and plant forms, while degraded soil looks like wasteland.

5.4. Spiritual and Social Significance: "Mother Earth"

In many cultures, soil (land) has a deep symbolic meaning. It is not just a substrate but Mother Earth, the source of life and fertility. For Slavs, as for many other peoples, "Mother Moist Earth" is an image of strength, fertility, and protection. Earth is what gives birth to bread, provides shelter, receives the bodies of the deceased.

In this sense, the concept of "native land" unites the physical and spiritual: birthplace, ancestors, culture, language—all are tied to a particular territory and its soils (Valkov et al., 2004). Loss of soil, its degradation, is not only an economic problem but also a loss of cultural identity. It is no coincidence that in many languages the words for "earth" and "country" share the same root (e.g., English land, German Land, Russian "земля" means both soil, country, and planet).

5.5. Recreational and Educational Functions

Soils underlie recreational areas: parks, beaches, sports fields, nature reserves. Soil quality determines opportunities for outdoor recreation—hiking, picnics, sports. For example, turf soils must be well drained, have sufficient firmness and elasticity for sports grounds (Weil and Brady, 2017).

Soils also serve as objects of educational activities. Soil pits, soil museums, and training grounds allow students and schoolchildren to study soil structure, properties, and processes. Understanding soil patterns is an important part of ecological and geographical education (Scheffer et al., 2018). Furthermore, gardening and horticulture are not only ways to obtain food but also forms of educational and therapeutic activity, especially in urban environments.

5.6. Scientific Value

Soils are objects of study for many sciences: pedology, geography, ecology, geology, climatology, archaeology, and even forensics (Weil and Brady, 2017). Soils provide information about past climates (palaeoclimatology), the rates and directions of geomorphological processes, and biological evolution.

In recent decades, research on soil carbon and its role in the global cycle has acquired enormous importance—this is now not only a scientific but also a political and economic task. Soil has become an object of international monitoring, giving its study particular value (Baldock and Broos, 2012).

5.7. Interconnection of Cultural Services with Other Functions

Cultural services are inseparably linked with other ecosystem services. Aesthetic appreciation of landscapes is impossible without fertile soils that support vegetation. Spiritual connection to native land is closely tied to traditional agriculture, which depends on soil health. The archaeological value of soil directly depends on its preservation and undisturbed state, which in turn is determined by regulating functions (protection from erosion, structural stability).

Thus, loss of soil functions (erosion, pollution, humus loss) leads not only to reduced productivity and water quality deterioration but also to impoverishment of humanity's cultural and spiritual experience. Therefore, soil protection is not only an agronomic or ecological task but also a task of preserving culture and historical memory.

5.8. Examples of Cultural Services in the Modern World

Rural and urban parks. Well‑kept parks with fertile soils become centres of recreation and aesthetic enjoyment for millions of people.

Soil museums and nature reserves. In various countries, soil museums are created where monoliths of the main soil types are displayed. Reserves preserve reference soils for scientific research and educational tourism.

Soil "brands". Some varieties of wine, cheese, vegetables are known for the special properties of the soils on which they are grown (terroir). This is a combination of provisioning (product) and cultural (regional identity, gastronomic heritage) functions.

Reclamation of disturbed lands. Restoration of soils after mining, construction, or pollution is not only a return to productivity but also restoration of the aesthetic and recreational potential of the land (Richter and Tugel, 2012).

Summary of the Cultural Services Section

Cultural services of soils are the facet that often remains in the shadow of economic activity, yet they make soil not just a resource but a part of human existence. Soil is:

A historical archive, preserving memory of the past;
A basis for landscape aesthetics, a source of inspiration and beauty;
A symbol of homeland, spiritual connection to place;
An object of education and science, allowing us to understand the world;
A foundation for recreation, providing rest and health.

Understanding the cultural services of soils helps us see that soil loss is not only economic damage but also destruction of cultural codes, loss of historical roots. Therefore, soil protection must be considered a priority not only for agricultural but also for cultural, spiritual, and social development.

In the final section of the lecture—"Why Society Depends on Soils"—we will summarise all categories of ecosystem services and show how they are interrelated and why soil conservation is a critical condition for a sustainable future for humanity.

6. Why Society Depends on Soils

We come to the main question of this entire lecture. After a detailed examination of the four categories of soil ecosystem services—supporting, regulating, provisioning, and cultural—we can answer it with complete certainty. Soils are important not only for agriculture because they are the foundation of the entire biosphere and human civilisation. Society's dependence on soils is multifaceted and extends far beyond food security. Let us explore why this is so.

6.1. Soil — The Basis of Food Security and Health

This is, of course, the most obvious and most studied connection. As already mentioned, about 98% of humanity's food comes from soil fertility (Valkov et al., 2004; Weil and Brady, 2017). But behind this figure lies more than just "food". Soils determine:

Food quantity. Soil fertility directly affects crop yields. Degraded soils produce low yields, threatening global food security (Weil and Brady, 2017; Scheffer et al., 2018).
Food quality. The micronutrient content in plants (zinc, selenium, iodine, iron) depends on their availability in soils. Soil micronutrient deficiency leads to "hidden hunger"—deficiencies of vitamins and minerals in human diets, which are causes of many diseases (Weil and Brady, 2017; White, 2006).
Food safety. Soils can accumulate toxic substances (heavy metals, pesticides, radionuclides), which then enter plants and food chains. Soil pollution is a threat to human health (Valkov et al., 2004; Weil and Brady, 2017).

Thus, providing the population with quality and safe food directly depends on the state of soils.

6.2. Soil — The Main Regulator of Water Resources

Water is the second most important resource for human life. Here, the role of soils cannot be overstated. Soils determine:

Water quality. Soils filter water, removing pollutants—suspended solids, toxins, and pathogenic microorganisms. It is thanks to soils that groundwater remains clean and drinkable (Weil and Brady, 2017; Valkov et al., 2004).
Water quantity. Soils store moisture during wet periods and release it during dry periods, smoothing fluctuations in river flow and preventing droughts and floods. Forest and grassland soils act as natural sponges, regulating the hydrological regime of landscapes (Ghezzehei, 2012).
Water availability for plants. Soil water‑holding capacity determines whether plants (and therefore crops and natural vegetation) can survive dry periods (Valkov et al., 2004).

Soil degradation (erosion, compaction, humus loss) leads to deterioration of water quality, increased floods and droughts, causing enormous economic and social damage.

6.3. Soil — A Key Factor in Climate Regulation

In the era of global warming, the role of soils in the carbon cycle becomes critical. Soils are the largest terrestrial carbon reservoir, storing 2–3 times more carbon than the atmosphere (Baldock and Broos, 2012).

Carbon sequestration. Under proper management (restoring organic matter, minimum tillage, returning crop residues), soils can absorb significant amounts of CO₂ from the atmosphere, mitigating the greenhouse effect (Baldock and Broos, 2012).
Greenhouse gas emissions. Under degradation (ploughing of virgin lands, draining peatlands, excessive fertiliser application), soils instead release large amounts of CO₂, methane (CH₄), and nitrous oxide (N₂O)—potent greenhouse gases (Scheffer et al., 2018).

Thus, sustainable soil management can become one of the key tools in combating climate change. Conversely, neglecting soil condition exacerbates the climate crisis.

6.4. Soil — Habitat for Enormous Biodiversity

Soils are one of the most species‑rich habitats on Earth. One gram of fertile soil can contain up to 10 billion microorganisms belonging to thousands of species (Scheffer et al., 2018; Weil and Brady, 2017). And most of these species have not even been described by science.

Microorganisms. Bacteria, actinomycetes, fungi, algae—they ensure nutrient cycling, decompose organic matter, suppress pathogens, produce antibiotics and other bioactive compounds. Soil microbiota is the "invisible army" working to sustain life (Weil and Brady, 2017).
Invertebrates. Earthworms, insects, nematodes, mites, centipedes—they participate in fragmentation of organic residues, structure formation, and soil aeration. Their diversity and abundance directly determine fertility (Valkov et al., 2004).
Vertebrates. Small mammals (moles, voles, ground squirrels), reptiles, amphibians also inhabit the soil or use it for shelter.

Loss of soil biodiversity is an irreplaceable loss of genetic capital that could become a source of new medicines, biotechnological solutions, and resilient crop varieties.

6.5. Soil — An Economic Asset and Means of Production

Soil is not only a natural resource but also a huge economic capital. The value of ecosystem services provided by soils is estimated in trillions of dollars per year (Millennium Ecosystem Assessment, 2005; Weil and Brady, 2017).

Agricultural production. The global turnover of agricultural products directly depends on soil fertility. Loss of fertility costs billions of dollars in annual losses and remediation costs.
Construction and engineering. Soils serve as foundations for buildings, roads, and bridges. Engineering properties of soils (bearing capacity, deformation resistance) determine construction safety and costs (Weil and Brady, 2017).
Raw materials. Sand, gravel, clay, peat, building materials are extracted from soils. Some soil types (e.g., bentonite clays) are used in industry as sorbents, fillers, components of drilling fluids (Valkov et al., 2004).
Tourism and recreation. Soils are the basis of landscape diversity attractive to tourists. Agricultural and natural landscapes, parks, and reserves create recreational value of lands.

The economic value of soils is often underestimated because many of their functions (water purification, carbon storage, biodiversity support) have no market prices. Yet their loss costs society far more than any investment in soil protection and restoration.

6.6. Soil — Keeper of Historical and Cultural Memory

We have already discussed this sufficiently in the cultural services section. However, it is worth emphasising once again:

Archaeological heritage. Ancient settlements, burials, and tools are preserved in soils. Study of soil profiles and cultural layers allows reconstruction of human history (Richter and Tugel, 2012).
Cultural identity. For every people, "native land" is not just a geographical territory but a spiritual connection to ancestors, birthplace, and traditions. Loss of soil cover (erosion, salinisation, pollution) is a loss of cultural roots.
Educational and scientific value. Soils are objects of study for many disciplines, from geography to biotechnology. Understanding soils fosters ecological awareness and a culture of natural resource use (Scheffer et al., 2018).

6.7. Soil — A Factor in Social Stability and Security

At first glance, the link between soils and social stability may seem unobvious, but it is very deep.

Food conflicts. Food shortages due to soil degradation cause social unrest, migration, and conflicts. Already today, in several regions of the world, soil degradation leads to food crises and forced displacements (Weil and Brady, 2017).
Employment. In developing countries, up to 70% of the population is employed in agriculture, which directly depends on soils. Loss of fertility means loss of livelihoods for millions of families.
International tensions. Competition for fertile land and water resources can exacerbate interstate relations, especially in regions with high demographic pressure and limited territories.
Migration. Soil degradation is one of the drivers of environmental migration. People leave lands that are no longer suitable for life, putting pressure on other regions.

Thus, soil health is directly linked to the socio‑economic stability of states and regions (Richter and Tugel, 2012).

6.8. Interconnection of All Services: A Systemic View

We have considered different categories of services separately, but in reality they are inseparably linked. Soil is a single system, and changing one property (e.g., loss of humus) simultaneously weakens several functions:

Decline in fertility (provisioning) → lower yields.
Deterioration of structure → reduced permeability and water‑holding capacity (hydrological regulation).
Loss of organic matter → reduced buffering and filtration (regulating services).
Weakening of biological activity → slowed element cycling (supporting services).
Reduced aesthetic and recreational value → loss of cultural services.

Conversely, improvement of one property (e.g., increasing organic matter content) positively affects all other functions. Therefore, sustainable soil management must be holistic, aimed at preserving and enhancing the full spectrum of ecosystem services, not just increasing yields.

6.9. What Does This Mean for the Future?

Recognition of the multifaceted role of soils in society should lead to changes in land‑use approaches.

1. Priority to soil protection. Soil is a non‑renewable resource on the human timescale. Preserving existing soils (protection from erosion, pollution, compaction) should become a paramount state task.

2. Investment in restoration. Restoration of degraded soils (reclamation, liming, gypsum application, organic amendments) requires significant expenditure, but these costs are many times offset by the restoration of ecosystem services and preservation of land productivity (Richter and Tugel, 2012).

3. Adaptive agriculture. Agriculture must be based on principles of maintaining and improving soil health, not on maximum exploitation of fertility. This means a shift to minimum tillage, crop rotations, use of organic fertilisers, and maintenance of plant cover (Baldock and Broos, 2012; White, 2006).

4. Interdisciplinary approach. Soil study should unite efforts of pedologists, agronomists, ecologists, economists, sociologists, historians, and representatives of other sciences. Only such a comprehensive approach can reveal all aspects of society's dependence on soils and develop effective management strategies.

References

Baldock, J.A., Broos, K. (2012). ‘Soil Organic Matter’, in Huang, P.Ming., Li, Y., Sumner, M.E. (ed.) Handbook of Soil Sciences Properties and Processes. Boca Raton, FL: CRC Press, pp. 11-1:11-52.
Ghezzehei, T.A. (2012). ‘Soil Structure’, in Huang, P.Ming., Li, Y., Sumner, M.E. (ed.) Handbook of Soil Sciences Properties and Processes. Boca Raton, FL: CRC Press, pp. 2-1:2-17.
Richter, D.deB. Jr., Tugel, A.J. (2012). ‘Soil Change in the Anthropocene: Bridging Pedology, Land Use and Soil Management’, in Huang, P.Ming., Li, Y., Sumner, M.E. (ed.) Handbook of Soil Sciences Properties and Processes. Boca Raton, FL: CRC Press, pp. 38-1:38-15.
Scheffer, F., Schachtschabel, P. (2018). ‘Einleitung: Böden – die Haut der Erde’, in Amelung, W., Blume, H., Fleige, H., Horn, R., Kandeler, E., Kögel-Knabner, I., Kretzschmar, R., Stahr, K., Wilke, B. (ed.) Scheffer Schachtschabel Lehrbuch der Bodenkunde. Deutschland: Springer-Verlag, pp. 1-10.
Turk, J.K., Chadwick, O.A., Graham, R.C. (2012). ‘Pedogenic Processes’, in Huang, P.Ming., Li, Y., Sumner, M.E. (ed.) Handbook of Soil Sciences Properties and Processes. Boca Raton, FL: CRC Press, pp. 30-1:30-29.
Weil, R.R., Brady, N.C. (2017). ‘The Soils Around Us’, in The Nature and Properties of Soils. Essex, UK: Pearson Education, pp. 19-50.
White, R.E. (2006). ‘Soil Quality and Sustainable Land Management’, in Principles and Practice of Soil Science. The Soil as a Natural Resource. Malden, MA: Blackwell Publishing, pp. 333-347.
Вальков, В.Ф., Казеев, К.Ш., Колесников, С.И. (2004). ‘Состав и свойства почв [Soil composition and properties]’, in Почвоведение [Soil science]. Москва - Ростов-на-Дону: МарТ, pp. 9-170.
Муха, В.Д., Картамышев, Н.И., Муха, Д.В. (2003). ‘Почва как многофазная полидисперсная система [Soil as a Multiphase Polydisperse System]’, in Агропочвоведение [Agropedology]. Москва: КолосС, pp. 29-40.