Soil Degradation and Erosion

Defined as the “loss of land’s physical, chemical, biological, and ecological qualities due to either natural or human-caused disturbances,” soil degradation is one of the largest and most dangerous environmental threats to humanity. Soil degradation could take form in many ways; some of which include soil erosion, compaction, salinisation, desertification, pollution, etc. Such problems could affect agricultural productivity, and by extension, food security across the globe. 

Soil Erosion

Soil erosion is the most frequent cause of soil degradation and is often caused by weathering. Soil erosion leads to an average loss of 75 billion tons of soil a year, which amounts to around 400 billion US dollars annually. 

Topsoil, the surface layer of soil, is often the most nutritious and precious part of soil. Unfortunately, this is also the layer that is easily taken away by winds or water-run off during heavy rain falls. In ions, particularly semi-arid regions, heavy winds may lead to erosion and desertification, leading to damaged top soils, affecting local crop harvests. 

You might have guessed that climate change is also largely responsible for the increasing common occurrence of soil erosion. The abnormal rainfall and extreme climate conditions caused by climate change often further increases the weathering and physical threat that the field surface has to resist against. 

Monocropping is a type of farming technique where only one crop species is repeatedly planted over multiple strips of land. Since the same crop often requires the same type of nutrients, this may lead to the depletion of the nutrient, which could result in land degradation and soil erosion. 

Additionally, conventional tillage of soil using manual tilling or moldboard plowing could lead to loose soils, leading to a loss of topsoil to winds and weathering. Overgrazing, also known as a phenomenon known as The Tragedy of the Commons, is an example of poor pasture management which destroys grass and soon, topsoil cover, which is often associated with long term depletion of topsoil nutrients. A bad case of soil erosion and land degradation may take up to decades to recover even with intervention.

Soil Salinization

Soil salinization is another example of soil degradation. As suggested by its name, soil salinization refers to an excessive accumulation of salts in the soil. This phenomenon occurs due to inadequate watering and high evaporation rates or poor drainage. There are protein pumps that line the cellular membrane of plant roots, these proton pumps actively pump salts and ions into the plant roots through the apoplast or symplast route, allowing the roots to passively absorb water as a result of osmosis. 

Soil salinization could increase the salt concentration in plant roots, creating a further osmotic gradient between the roots and the soil, causing a shriveling in plant cells also known as plasmolysis. Soil salinization is often harder to mitigate or prevent when compared to soil erosion since salt content is not visible to the eye unless practical damage has been dealt to plants. Unfortunately, at that time, the salinization could already slow crop growth and render the soil unsuitable for further cultivation of crops.

How to Fix Soil Degradation 

Although soil degradation could potentially take a long time to fully fix, there are fortunately many preventive measures that could be taken to ensure your soil remains in good condition. Practicing no-till or reduced tillage techniques could lower the soil’s vulnerability to erosion and weathering by letting the soil naturally sit. Another method is to practice crop rotation by alternating the crop type grown in your soils by the season. Such techniques could help ensure that there isn’t a singular nutrient in soils that are depleted, at the same time providing a range of different nutrients from the plants to the soil. Happy farming!

Works Cited

https://eos.com/blog/soil-degradation/

https://eos.com/blog/soil-erosion/