Soil erosion is a kind of soil degradation that occurs naturally on all land. However, it is usually heavily influenced by human activity. Soil erosion’s natural causes are typically similar to the causes for other types of erosion: mainly water, wind, ice, and gravity.
The most devastating effects of soil erosion are the degradation of fertile land and water pollution and all the negative effects that come with them. For these reasons, learning how to prevent soil erosion is crucial for any community.
Causes of Soil Erosion
The first step in reducing soil erosion is to properly understand the causes behind it. It is usually caused by several factors working together, both natural and man-made. It is difficult to pinpoint the exact causes for each situation, so all potential factors have to be taken into consideration.
Usually, the natural causes of soil erosion cannot be fully eliminated, only contained. One cause of soil damage is from the massive amounts of water dropped by heavy rains. This deluge sweeps away the top part of the soil, which contains important nutrients, thus decreasing the quality of the soil. Wind is another major natural cause of erosion, as it tends to lift and transport light and sandy soils, decreasing land quality.
The most significant man-made factor of soil erosion is heavy farming. Overworking the land for long periods of time will greatly affect the land’s structure and deplete it of nutrients. Tilling especially damages the soil. So how does no-till farming reduce soil erosion? It does so simply by keeping a constant land structure. Vegetation is, however, needed to avoid soil erosion, so a complete lack of plants and crops is also a contributing factor, as is the deforestation of a piece of land. In his book, “The Political Economy of Soil Erosion in Developing Countries,” geographer and environmentalist Piers Blaikie argues that most man-made factors of soil erosion are caused by mismanagement and lack of funds in developing countries.
Soil Erosion Solutions
Soil erosion prevention is vital for the well-being of a community and can be achieved by following a series of steps. Most ways of preventing soil erosion rely on eliminating the causes or limiting the natural events that lead to the erosion of land. Prevention is done with the help of ecotechnology, which is using technology and knowledge to better manage human interaction with nature.
The lack of vegetation on a piece of land is a major cause of soil erosion, as factors such as heavy rains or strong winds will do significantly more damage to bare soil. That is why using plants to prevent soil erosion is an efficient move. Vegetation not only keeps the soil in place, thanks to the plants’ roots, but also provides the soil with valuable nutrients from fallen leaves, fruit, or animal droppings. The result is a portion of land that is able to withstand the effects of wind and water, therefore preventing degradation.
For areas in which planting vegetation is not an option or is only in the initial phases, adding rocks and mulch is a good way of controlling soil erosion. The effects are similar to those that come from vegetation, meaning the soil will be heavier and less likely to be displaced by rain or wind. Keeping a fertile topsoil means that plants will start to grow, even from beneath the rocks or mulch, further strengthening the land.
Steep slopes present extra challenges for preventing soil erosion, as another natural factor, gravity, joins rain and wind in causing damage. In this case, the solution is to use a soil erosion mat, which is basically a nonbiodegradable soil erosion control blanket that is placed over the seeds or young plants. This blanket holds the top part of the soil in place, even when it is threatened by multiple natural causes of erosion. If soil erosion mats can’t keep massive amounts of water from carrying mud downhill, putting down fiber logs will block the water and keep it on the soil.
Properly draining water from the soil is another major part of fixing soil erosion. If the land is not properly drained, it will only take a heavy rainfall for water to build up and wash away nutrient-rich topsoil. Watering of plants must be kept to a minimum and constantly adjusted, depending on the amount of rain that falls in a particular period of time. Ideally, irrigation and underground drainage systems will be put in place for efficient water management.
Among the soil erosion prevention techniques, avoiding soil compaction is one of the most important. The constant movement of people, cattle, or machines on a particular piece of land will press down the soil, making it harder and denser. Since compacting reduces space between dirt particles, water is not able to drain through; instead, it carries the soil downhill. Compacted soil also makes it harder for plants to push through, reducing the vegetation needed for healthy soil. Creating walking paths and keeping machines and cattle off the land will help to prevent soil erosion.
How Does Terracing Prevent Soil Erosion?
Terracing is a very effective method to stop soil erosion on sloped plains. Basically, it means cutting the sloped land and forming many receding flat surfaces that resemble steps. Historically, terracing has been used with great success throughout the world and is still used today, mostly in Southeast Asia, the Mediterranean, Africa, and South America. It also is used on islands with steep slopes and allows farming in places that would not have been accessible otherwise.
The reasons for why terracing works are mostly related to the flow of the water that comes from rains. First, the speed at which the water circulates downhill is greatly reduced, preventing it from taking off the top part of the soil. Another upside is that since the water travels more slowly, more of it will be absorbed by the land. This feeds the plants and prevents downhill floods. However, for terracing to work, the system has to be not only well-designed but also properly managed. According to the book, “Terracing for Soil and Water Conservation” by Claude L. Hamilton, inadequate tillage practices or overcropping can make terraces fail only a few years after they have been put to use.
Soil erosion is and has always been a major problem for humanity. Damaged land will not only prevent the growth of rich crops but will also enable other natural calamities, such as major floods caused by the land not absorbing the water. Although soil erosion is partly inevitable due to its natural causes, good farming practices and soil management techniques will help control and prevent it.
List of sources:
The Political Economy of Soil Erosion in Developing Countries, Piers Blaikie
Terracing for Soil and Water Conservation, Claude L. Hamilton
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