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Soil erosion and degradation: a global problem – Effects (Part 2)

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The consequences of soil erosion are primarily centered on reduced agricultural productivity, as well as soil quality. But also, water ways may be blocked, and it may affect water quality. This means, most of the environmental problems the world face today, arises from soil erosion.

Particularly, the effects of soil erosion go beyond the loss of fertile land. In other words, it has led to increased pollution and sedimentation in streams and rivers, clogging these waterways and causing declines in fish and other species. And degraded lands are also often less able to hold onto water, which can worsen flooding.

So, the effects of soil degradation include:

  1. Loss of arable land: Lands used for crop production have been substantially affected by soil erosion. Soil erosion eats away the top soil which is the fertile layer of the land and also the component that supports the soil’s essential microorganisms and organic matter. In this view, soil erosion has severely threatened the productivity of fertile cropping areas as they are continually degraded. Because of soil erosion, most of the soil characteristics that support agriculture have been lost, causing ecological collapse and mass starvation.
  1. Water Pollution and Clogging of Waterways: Soils eroded from agricultural lands, carry pesticides, heavy metals, and fertilizers which are washed into streams and major water ways. This leads to water pollution and damage to marine and freshwater habitats. Accumulated sediments can also cause clogging of water ways and raises the water level leading to flooding.
  1. Increased flooding: Land is commonly altered from its natural landscape when it rids its physical composition from soil degradation. In other words, soil degradation takes away the soil’s natural capability of holding water thus contributing to more and more cases of flooding.
  1. Drought and Aridity: Drought and aridity are problems highly influenced and amplified by soil degradation. As much as it’s a concern associated with natural environments in arid and semi-arid areas, the UN recognizes the fact that drought and aridity are anthropogenic induced factors especially as an outcome of soil degradation. Hence, the contributing factors to soil quality decline such as overgrazing, poor tillage methods, and deforestation are also the leading causes of desertification characterized by droughts and arid conditions.
  1. Destruction of Infrastructure: Soil erosion can affect infrastructural projects such as dams, drainages, and embankments, reducing their operational lifetime and efficiency. Also, the silt up can support plant life that can, in turn, cause cracks and weaken the structures. Soil erosion from surface water runoff often causes serious damage to roads and tracks, especially if stabilizing techniques are not used.
  1. Desertification: Soil erosion is also responsible for desertification. It gradually transforms a habitable land into deserts. The transformations are worsened by the destructive use of the land and deforestation that leaves the soil naked and open to erosion. This usually leads to loss of biodiversity, alteration of ecosystems, land degradation, and huge economic losses.

Finally, we all understand that the erosion of the soil is a very serious issue, especially in our days. That is why we need to take action and prevent the unpleasant effects.

Dipla Aikaterini (Arid Zone Afforestation)

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Soil erosion and degradation: a global problem – Causes (Part 1)

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Soil degradation, defined as lowering and losing of soil functions, is becoming more and more serious worldwide in recent decades, and poses a threat to agricultural production and terrestrial ecosystem.

Particularly, soil degradation simply means the decline in soil quality, which comes about due to aspects such as improper land use, agriculture and pasture, urban or industrial purposes. It involves the decline of the soil’s physical, biological and chemical state. In other words, it is a process that leads to decline in the fertility or future productive capacity of soil, as a result of human activity.

It is well known that all soils undergo soil erosion, but some are more vulnerable than others, due to human activities and other natural causal factors. The severity of soil erosion is also dependent on the soil type and the presence of vegetation cover.

Here are few of the major causes of soil degradation:

  1. Physical factors: There are several physical factors contributing to soil degradation, distinguished by the manners in which they change the natural composition and structure of the soil.  Rainfall, surface runoff, floods, wind erosion, tillage, and mass movements result in the loss of fertile top spoil thereby declining soil quality. All these physical factors produces different types of soil erosion (mainly water and wind erosion) and soil detachment actions, and their resultant physical forces eventually changes the composition and structure of the soil by wearing away the soil’s top layer as well as organic matter.
  1. Chemical factors: The reduction of soil nutrients because of alkalinity or acidity or water logging, are all categorized under the chemical components of soil degradation. In the broadest sense, it comprises alterations in the soil’s chemical property that determine nutrient availability.
  1. Biological factors: Biological factors refer to the human and plant activities that tend to reduce the quality of soil.  Some bacteria and fungi overgrowth in an area can highly impact the microbial activity of the soil through bio-chemical reactions, which reduces crop yield and the suitability of soil productivity capacity. Also, human activities such as poor farming practices may also deplete soil nutrients thus diminishing soil fertility.
  1. Deforestation: Deforestation causes soil degradation on the account of exposing soil minerals by removing trees and crop cover, which support the availability of humus and litter layers on the surface of the soil. When trees are removed by logging, infiltration rates become elevated and the soil remains bare and exposed to erosion and the buildup of toxicities.
  1. Improper cultivation practices: There are certain agricultural practices that are environmentally unsustainable and at the same time, they are the single biggest contributor to the worldwide increase in soil quality decline. For example, due to shortage of land, increase of population and economic pressure, the farmers have adopted intensive cropping patterns of commercial crops in place of more balanced cereal-legume rotations.
  1. Misuse and Extensive cultivation: The excessive use and the misuse of pesticides and chemical fertilizers kill organisms that assist in binding the soil together. In other words, it increases the rate of soil degradation by destroying the soil’s biological activity and builds up of toxicities through incorrect fertilizer use. We all know that due to tremendous population increase, the use of land is increasing day by day.
  1. Overgrazing: The rates of soil erosion and the loss of soil nutrients as well as the top soil, are highly contributed by overgrazing. Overgrazing destroys surface crop cover and breaks down soil particles, increasing the rates of soil erosion. As a result, soil quality and agricultural productivity is greatly affected.
  1. Industrial and Mining activities: Soil is chiefly polluted by industrial and mining activities. For example, mining destroys crop cover and releases a myriad of toxic chemicals such as mercury into the soil thereby poisoning it and rendering it unproductive for any other purpose. Industrial activities, on the other hand, release toxic effluents and material wastes into the atmosphere, land, rivers, and ground water that eventually pollute the soil and as such, it impacts on soil quality. Altogether, industrial and mining activities degrade the soil’s physical, chemical and biological properties.
  1. Roads and Urbanization: Urbanization severely affects the erosion process. Land denudation by removing vegetation cover, changing drainage patterns, soil compaction during construction and then covering the land by impermeable layers of concrete or asphalt, all of them contribute to increased surface runoff and increased wind speeds.

Finally, taking into consideration all the above, we understand that soil erosion is a continuous process and may occur either at a relatively unnoticed rate or an alarming rate contributing to copious loss of the topsoil. So, we have to be careful and avoid all the above problems.

Dipla Aikaterini (Arid Zone Afforestation)

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