We were taught that plants help prevent soil erosion from a young age, but our science classes didn’t always go into depth about its mechanics. Even if we don’t fully understand how it works, it’s easy to see firsthand. When driving down the highway on a windy day, the dust blows like crazy across barren ground compared to areas covered in plants.
In order to talk about how plants help prevent soil erosion, let’s first talk a bit about what soil erosion is and why it’s a problem.
Soil erosion is the loss of topsoil over time. It is a gradual process where different agents move the upper soil layer to a new location. This is problematic because it removes the nutrient-rich planting layer, impacting soil fertility. When the soil settles in its new location, it also tends to cause environmental problems such as sedimentation in streams, rivers, and lakes and surface and groundwater pollution.
While there are numerous causes of soil erosion, water and wind are the key players. Water is the primary cause of erosion. Raindrops or water flowing across the soil surface pick up and move soil particles to a different location, continuously removing the layer of topsoil. Strong winds do something similar, blowing soil as dust to other spots.
Both processes are inevitable, but there are ways to minimize soil loss. This is where plants become so beneficial.
So let’s answer the question, how do plants prevent soil erosion? Just like erosion happens in different ways, by various forces, there are numerous ways plants help prevent it.
- An extensive root system put out by the plants weaves through to the soil like a net. This gives the ground the structural strength needed to hold it in position and keep it from moving.
- As rain falls, leaves on vegetation take the brunt of the rain’s force. Instead of hitting the ground hard, displacing soil, rain droplets hit the plants first. The foliage absorbs the water’s energy, causing it to trickle to the ground or fall much more gently.
- Plants cover the soil surface, acting as a thick barrier. When the wind blows, they take the brunt of the velocity, slowing down the air current. This robs the wind of its natural energy. When the wind reaches the ground, it isn’t strong enough to pick up soil particles.
- Plants cast shade over the ground, reducing evaporation rates, and keeping more moisture in the soil. Wet soil particles are heavier than dry ones, so the soil is less apt to be blown away due to strong winds.
- Microorganisms build colonies in the soil around plant roots. As they feed on organic matter, they release “sticky” organic compounds. Roots also naturally exude similar compounds. These compounds work like glue, binding the soil particles together, making them harder to move.
When we grow groundcover like grass on a hillside it is the plant and it’s root system that the holds the soil in place which in turn prevents nutrient loss to wind and water.
Before we dig deeper let’s define soil next.
What Is Soil vs Ordinary Dirt
In order to understand anything related to soil erosion, it is really important to actually understand what soil is. Soil is generally defined as the upper layer of the crust, that has been formed by the breaking down of rocks over a period of millions and millions of years under the influence of the natural forces of weathering and erosion, and is ultimately the result of all of these forces plus the biotic factor consisting of living plants, animals, fungi, bacteria etc as well as their wastes and remains.
To put it a little more simply, soil is the upper layer of the crust which contains humus and on which plants and animals survive and thrive.
The Interdependence of Plants and Soil
Plant and soil together constitute the flora part of our ecosystem. Honestly, it’s pretty evident that plants can’t live without soil. Plants not only exist on soil, but they draw a lot of things from the soil. For example, plants draw water from the soil that they need to perform photosynthesis on a daily basis. Plants also draw a lot of nutrients from the soil such as Nitrogen, Phosphorous, Potassium and so on.
Again, while plants do take all of these, they also support the soil. The root of the plant actually hold the soil in one place. You must have read or even seen that soil at barren places gets eroded pretty easily. This is so because there are no roots actually holding it. When there are plants present on the soil, the roots go deep inside it and they hold it all together. Also, the plants discard a lot of things such as leaves, fruits, and even die after a certain point, only to be decomposed by bacteria to add to the overall nutrient level of the soil.
Thus, we can easily see that plants and soil have a special relation between them. Both of them depend on one another, and actually help one another in the long run! Still wondering about How do Plants Prevent Soil Erosion? Well hold on, we will be getting to it soon enough!
Soil Erosion and its types
Soil erosion is defined as the removal of the upper covering of the crust (or the soil) from its proper location. It must be noted that erosion only deals with the removal, it may or may not be deposited elsewhere, but that’s part of the deposition process.
Naturally, soil erosion can happen because of several factors. Based on these, it has been divided into various types, such as:
Soil is mostly eroded under the influence of water, though wind often plays a major role too. Flowing water as well as rainwater has a serious impact on soil that’s left open, and can easily erode it away. This process is known as Water Erosion. Depending on the specifics, it can be of three types:
- Sheet Erosion: When the overall upper layer of soil comes off like a sheet, it is known as sheet erosion. The overall surface is eroded away in a more or less uniform way, and so it might be a little hard to notice, because it happens gradually and uniformly.
- Bank Erosion: As is obvious from the name, this specific kind of erosion is noticed at the riverbanks. The flowing river often erodes away its own banks, which ultimately can be noticed by the increase in the width of the river overtime.
- Rill Erosion/Channel Erosion: Channel erosion can occur on steep land or on land that slopes more gently. Because there are always irregularities in a field, water finds hollows in which to settle and low-lying channels through which to run. As the soil from these channels is washed away, channels or miniature dongas are formed in the field.
As I remarked earlier, soil might also be eroded under the influence of wind. While this rarer and takes a much longer time with regular soil, it can be shown in a much simpler manner with the example of the formation of sand dunes. These are formed when winds blow sand from one place and deposit them at an entirely different place, which might be far away from their actual position!
Factors Determining Soil Erosion
Soil erosion is not subject to only the rate of erosion or the nature of the erosive forces. There are several factors that actually determine the level of Soil Erosion, and these might be briefly summed up in the following points:
- Slope: The Slope of the land is a deciding factor for Soil Erosion. Naturally, if the land has a steep slope, it favors erosion since gravity also tries to move it away. So, that’s one of the positions where it might be a little harder for you to actually be able to grow even Grass. If you’re interested in knowing how you might be able to do so, click here for our article on how to grow grass on a steep hill.
- Soil Texture: Soil Texture is another important factor. The Soil can be Sandy, Clayey, or Loamy and each of these have a different impact on the rate of erosion. So, knowing the soil type is essential to knowing the actual rate of erosion as well!
- Vegetation Cover: As we are discussing in this article, Vegetation cover actually helps check soil erosion. So, that’s an important thing that decides exactly how much soil erosion would be over a certain area. Naturally, places that are barren would face a greater level of soil erosion.
- Shifting cultivation: Practicing Shifting Cultivation is really harmful because it makes the soil exposed. So, that’s something that must always be avoided, because places where it is practiced face a really high level of soil erosion.
How Do Plants Stop Soil Erosion?
Plants, as we remarked earlier, are entirely dependent on the soil. Not only do they just live on the soil, they actually push their roots deep inside it to tap into the water and mineral content underground- something that they need to survive and grow.
While plants put these roots inside for actually tapping on to its essential resources, it actually ends up holding the soil together. The network of roots laid out by plants and trees actually hold the soil in its own place, and prevents it from getting washed away.
In case of strong winds, the plants also act as a cover that does not let the wind directly touch the soil, and thus the soil is saved. Even when it comes to flowing water, the plants hold the soil tightly enough to prevent the water from actually eroding the soil.
So, in the long run, it can safely be said that the extensive network of roots laid down by the plants actually holds the soil in position, and gives it the structural strength it needs to stay in the right place, and not be moved by the natural agents of erosion. And thus, the plants do really prevent soil erosion!
What are some of the other methods to prevent Soil Erosion?
Naturally, soil erosion isn’t something we want, especially us lawn-owners. After all, we worked so hard to prepare the soil for our plants! So, while we can’t do anything specific that would ensure that it’s prevented, we can take several precautions. Some of the main things that you might want to do are as follows:
- Windbreaks is a really great idea. As I said earlier, wind erosion might be really prominent for specific areas. For such cases, windbreaks become a really good idea because they would be able to save your soil to a great extent.
- Avoiding Overgrazing: Overgrazing is a major problem in a lot of the areas because the people simply don’t know about soil erosion. Overgrazing has been identified as a leading factor owing to which soil erosion is becoming more and more evident. So, avoiding it seems like one of the best ideas to go for!
- Avoiding Overwatering: Overwatering also makes the soil prone to erosion. So, if you want to check soil erosion, you must check on overwatering as well. We realize how easy it is to overwater your lawn, and we are here to help find out the exact amount of water you should use. Please click here to read our article on how long you might want to water your plants.
- Prevention of Shifting Cultivation: Preventing Shifting cultivation is also absolutely necessary to actually minimize soil erosion. This is one of those cases where man takes a direct and active part in promoting soil erosion, and is comparatively easier to control than the natural forces, and we must try our best to do so.
It is almost impossible to stress enough on how serious of an issue Soil Erosion is. Quoting Scientific American:
The economic cost of soil erosion is estimated to be several billion dollars every year for the U.S.
This alone can give us an idea about how serious this problem is even in only the U.S. Even besides these estimates, the loss it might cause for the average lawn-owner like you and me is immense, because we put in all our hard work all throughout the year to get the dream-lush lawn!
So, planting the right trees and following the few steps we mentioned earlier are the best ideas to actually control soil erosion in the long run. It is hoped that people would realize what’s wrong, and that they would actually realize their responsibility towards the planet and its environment and work together to lay the foundation for a safer and a better future for not only man, but for all the living beings that inhabit the earth.