How do humans cause soil degradation and how does this impact food security?



  1. 0 Votes

    Cracked soil

    Soil degradation is an important environmental problem with growing consequences for food security. With more than six billion people relying on food grown on just 11 percent of the earth’s land surface today and only a mere 3 percent actually holding naturally fertile soil, soil degradation needs to be given more attention when viewed by the fact that we are destroying soil faster than ever before [1].  Studies commissioned by the United Nations Environment Program (UNEP) along with the Food and Agricultural Organizations of the United Nations (FOA) have proven soil degradation’s growing  impacts on food security and even climate change.

    Soil degradation must be looked at as a case by case study because its impacts on food security vary depending on the region and institutions set in place for each location.  It is an extensive and increasingly interconnected issue with a host of other problems such as over-population and unequal land ownership that cannot be prescribed a one size fits all solution. Let’s take a closer look at soil and the definition of soil degradation first.

    Soil is composed of living organisms and decaying organic matter mixed with pebbles, sand, clay, silt, air, water, and nutrients.  What will grow in a soil depends on its mix and amount of nutrients [2].  Healthy soil is needed to sustain life and not all is created equally; there are many factors contributing to the quality of the soil, one being humans.  Humans can both enhance and destroy the soil’s quality. 

    Soil degradation is defined as “a decline in long-term productive potential” of the soil [3].  This occurs when human activity, whether directly, or indirectly causes the soil to become less healthy by pushing production levels beyond the land’s ability to support them resulting in the land becoming less able to support plant and animal growth.  There are three ways in which a soil can degrade.  One way is through a physical, chemical or biological run-down that causes a reduction in plant health by depleting soil nutrients or reducing plant growth.  Soil can also degrade by a reduction in mass and volume through erosion; this reduces the physical size of the soil’s ecosystem.  The third way is due to soil chemicals such as soluble salts or industrial chemicals accumulating to levels that effect plant growth detrimentally [4]. 

    Clearing and burning of steep slopes and the erosion caused by it

    These three processes are both created and exacerbated by human activity, most commonly through agricultural production.  Inappropriate land-use practices can lead to erosion, chemical contamination, compaction, salinity, and in extreme cases stop plant growth altogether [4].  A common form of soil degradation seen in developing and developed countries alike is compaction.  This commonly occurs with heavy farming machinery that compacts the earth as it rolls over it.  This leads to roots not being able to penetrate the ground and because water cannot drain into the earth, it runs off and creates water erosion [1]. 

    There is much more concern in many parts of the developing world over other forms of soil degradation which include human-induced erosion and desertification.  This is most exemplified by China’s Loess Plateau which contributes to one of the world’s highest erosion rates [1].  Wind erosion occurs when trees are cut or livestock are allowed to overgraze, this makes it easier for the wind to blow away nutrient-rich topsoil.  Further, too much fertilizer or pesticides can acidify or pollute the soil while too little causes plants to leach nutrients from the soil.  Poor irrigation systems can also lead to salinity that dries out the soils, eventually making it incapable of producing [2]. 

    Ethiopia 2008. Cattle, looking for food

    The connection between food security and soil is now more than ever being realized.  In the past couple years, food shortages have been caused partially by the decreasing quantity and quality of the world’s soil leading to riots in Asia, Africa, and Latin America [1]. Since agricultural production is an important source of income for much of the world’s rural poor, the quality of their soil has a major impact on their capacity to achieve food security [5].  In addition to this, most agricultural land in developing countries fall outside the category of high-quality land, making the already marginal and over-exploited land even more so [3]. 

    Hungry Hands

    With poor soil quality, people lose the physical access to food because soil degradation limits the food production; this is aggravated by many poor people’s inability to migrate to better land.  Soil can directly affect food security through yields produced.  When the process of soil degradation sets in, farmers receive lower and lower yields each year until eventually their soil becomes obsolete and new land must be cleared.  This vicious cycle recurs throughout the developing world leading to other environmental problems such as deforestation. 

    As the issue of soil degradation and its growing consequences in countless areas such as world poverty and deforestation are increasingly realized, people will begin to realize that much of our environmental and social woes can be traced back to such basic levels as how we treat the soils we walk on.

    life in dry soil







  2. 0 Votes

    In a bit of a shorter answer, humans remove groundcover and other sources of plants that prevent erosion. Erosion causes the valuable nutrients to wash away from the soil, which results in soil that is much more difficult to grow healthy plants in, inlcuding fruits and vegetables.

    I hope this helped!

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