Did you know that it takes a staggering 1,000 years to produce just 2-3 centimeters of topsoil? Yet, this precious layer, crucial for life as we know it, is disappearing at an alarming rate. Soil degradation — the silent crisis beneath our feet — affects nearly a third of the Earth’s land area, impacting food production, water quality, and even the air we breathe.

As we tread on this fragile foundation, understanding soil degradation is not just about the ground below but about the future of our planet. Let’s understand this often overlooked but critical environmental challenge and discover the story of the world beneath our shoes.

What is Soil Degradation?

The loss of a soil’s fundamental physical, chemical, and/or biological properties due to anthropogenic or natural processes is known as soil degradation. This leads to the reduction or eradication of key ecosystem services.

Usually employed for agricultural, industrial, or urban purposes, soil degradation is the loss in soil quality brought on by incorrect usage or inadequate management. It is a significant issue for the environment. The foundation of all terrestrial life is soil, which is a key natural resource. Our well-being depends on healthy soil.

Global food security is at risk due to soil degradation, which causes 36–75 billion tonnes of yearly land loss and freshwater shortages. For the ecosystem to stay diversified and viable, the soil is a fundamental component that must be healthy. Environmental change and anthropogenic effects are potential threats to soil fertility survival.

A reduction in soil fertility, unfavorable changes in alkalinity, acidity, or salinity, excessive floods, the use of hazardous soil contaminants, erosion, and a decline in the structural integrity of the soil are instances of soil degradation.

Each year, these factors cause a substantial amount of soil quality degradation. Thus, excessive soil degradation has both short-term and long-term effects that negatively influence the ecosystem globally.

Soil Acidity 

When the pH of the soil is lower than a neutral pH (less than 7), the condition is known as soil acidity. The hydrogen (H+) ion concentration is used to express the pH of the soil. It serves as a gauge of how actively H+ interacts with the soil’s constituents, the nutrients in the soil solution (water), and the plants that are growing there.

When a soil profile is leached, soil acidification can occur naturally; however, certain agricultural techniques and acid precipitation, sometimes known as acid rain, can speed up the process.

In the majority of areas across the globe, soil acidity is quickly becoming a concern. Acidic soils produce production issues by reducing the availability of some crucial plant nutrients and increasing the availability of poisonous components in the soil solution, such as manganese and aluminium. These are also the main factors in acidic soils’ poor crop performance and failure.

Below 5.5 on the pH scale, which measures how acidic the soil is. Aluminium concentration may be high enough to restrict or prevent root growth (the lower the pH, the more acidic the soil). Plants are stunted, show signs of nutritional insufficiency, and are unable to absorb water and nutrients as a result (especially those for phosphorus). Manganese in toxic amounts prevents the aerial plant parts from growing normally, which stunts, discolours, and reduces yields.

Soil Salinity 

In the upcoming years, soil salinity is anticipated to have a more significant and widespread impact on the planet. Salinity in water resources also rises as a result of rising soil salinization. Fertile land becomes unproductive due to soil salinity, which eventually causes economic loss. A reduction in soil salinity is closely correlated with soil irrigation.

The most severe issue that hinders plant development is soil salinity. It has been shown that the strongest inhibitors to plant development are soil salinity and boron toxicity. Under salt stress, the majority of plants do not completely express their genetic potential for growth, development, and yield, which causes a decline in their economic and commercial worth.

Salinity is a problem for the quality of soil and water, particularly in arid and semiarid regions where the need for water for irrigation and agriculture is growing daily. Arid and semiarid zones are those where there is not enough precipitation to remove excess sodium ions and salts from the rhizosphere. The majority of saline soils include very insoluble calcium salts and calcites.

The country has 6.74 million acres of salt-affected land. According to estimates, an additional 10% of land becomes salinized annually, and by 2050, around 50% of the world’s arable land will be contaminated by salt. Twelve states and one Union Territory have 44% of their land covered by saline soils, whereas eleven states have 47% of their land covered by sodic soils.

Read More: Measuring soil salinity

Soil Desertification 

Land deterioration in arid, semi-arid, and dry sub-humid regions, collectively known as drylands, is referred to as desertification and is caused by a variety of reasons, including climate changes and human activity.

The term “desertification” does not mean that current deserts are growing larger. It happens as a result of dryland ecosystems’ high susceptibility to overexploitation and unsuitable land use, which account for over one-third of the world’s land area. The productivity of the land can be negatively impacted by poverty, political unrest, deforestation, excessive grazing, and poor irrigation techniques.

Over the past few decades, certain dryland areas have seen a rise in the breadth and severity of desertification. In certain dryland areas, desertification has already decreased biodiversity and agricultural output, and revenue.

The proliferation of invasive plants has resulted in losses in ecosystem services in many dryland areas, while over-extraction is contributing to groundwater depletion. Unsustainable land management has decreased human well-being in drylands and elsewhere, especially when paired with droughts. It has also increased the frequency of dust storms.

Read More: Desertification Global Status

Soil Erosion 

Soil erosion is the natural process of topsoil erosion that occurs when physical forces like wind and water carry away the soil from a field.

Topsoil erosion is occurring at an alarming rate. As a result, there is ongoing topsoil loss, ecological harm, soil collapse, etc. The soil fragments are loosened or washed away during this process in valleys, seas, rivers, streams, or far-off areas. Due to human activities like agriculture and forestry, this has gotten worse.

Soil detachment, movement, and deposition are three separate processes that occur during erosion, whether it is caused by water, wind, or tillage. Topsoil, which is rich in organic matter, fertility, and soil life, is either moved “off-site” to fill up drainage channels or moved “on-site” where it accumulates over time. The contamination of nearby waterways, marshes, and lakes is a result of soil erosion, which also lowers the yield of agriculture.

The amount and quality of soil ecosystems and arable land are both decreased by soil erosion. Unchecked, severe soil erosion can lead to the destruction of food crops, have a detrimental effect on community resilience and livelihoods, and even change ecosystems by lowering biodiversity above, within, and below the topsoil.

Also Read: Floods and Land Erosion: Causes, Effects and Measures