First off, erosion and weathering are not the same things. They are often confused with each other because they often occur at the same time. Physical weathering is when a rock gets broken down either by wind or rain or something else.
Erosion, in broad terms, is the moving of soil, dissolved material, and/or broken rock particles from the site of the original location to someplace else. It is not a good thing even if it’s a natural occurrence, mostly.
People can cause or increase the potential of this natural occurrence. In addition to moving rock particles and soil, debris and chemicals can also be moved by erosion causing buildups in low areas.
Some effects of erosion are flooding, poor water quality, poor soil quality, and loss of landmass.
There are many erosion types in farming that fall under two main categories: water and wind. Examples of erosion in these areas are listed below.
1. Rill Erosion
This is the most common form of water erosion seen by farmers.
Whenever you see deep yet narrow channels carved into the ground by runoff, especially around your garden or house, these are rills.
Unless they’re filled in, they can become a hazard.
2. Raindrop or Splash Erosion
Rain comes in many forms from a light sprinkle to a heavy downpour.
When the raindrops hit the ground directly, it hits with enough force to break the soil apart, and then, it is washed away with the rainwater.
3. Gully Erosion
This is another type of water disintegration that is caused by highly concentrated runoff that cuts deep grooves into the ground and can’t be filled in like Rills can be.
Many start as small drainage areas like rills and grow as the runoff surges and collapses the sides of the original groove. Deserts are full of gullies.
4. Sheet Erosion
This is caused when wind or water strips away large portions of topsoil from an area all at once.
Anything loose can be swept away with the soil, but the loose soil is the one thing we don’t want to lose.
5. Linear Erosion
This is a form of water runoff that causes scratches or gouges in the soil. If not prevented, they can develop into more severe forms of erosion.
6. Mass Movement aka Landslide
Landslides are caused by water undermining the integrity of slopes causing them to be washed away by the water.
This happens during heavy rains and flooding, sometimes at the same time. Landslides can be formed of just rock, rock, and soil or, in severe cases, entire mountainsides.
7. Streambed Erosion
Erosion of stream beds happens when the sides of the stream collapse due to heavy rains and/or flooding.
Usually, the banks of the streams have very little vegetation or rock so the soil is easily stripped away.
8. Tunnel Erosion
There are times when water hits the ground so hard it drills a hole into the earth and then follows gravity underground, creating a tunnel.
It can also follow the interiors of burrows and old drainage pipes. As more water flows into the tunnel and then floods over it, it causes the tunnel to collapse.
All the soil and rock are then swept away with the water.
This type of erosion is caused by the wind. It’s the stripping away of soil/sand to expose underlying rock, roots, and anything else under loose soil.
Unlike sheet, deflation can happen in small areas and is only caused by the wind.
This is another type that is caused by wind. Soil/sand is left wherever it falls once the wind dies down.
Accumulation can create dunes, build up areas along the edges of fields, and fill up small streams and other water sources. This kind of buildup is not necessarily beneficial.
This is caused by droughts when overgrazed land is subjected to a decent wind.
The lack of ground cover allows the wind to sweep away all loose soil creating a barren spot in an otherwise verdant area.
12. Glacial Erosion
Everyone knows a glacier is one big moving mountain, or hill, of solid ice. Only it’s not just ice. As glaciers thaw and freeze, they move.
As they move, they dig into the ground. They take along with them loose soil and even rock. They are said to have carved the coastal area of many islands in the north.
13. Tillage Erosion
Tilling the soil creates deep grooves in the ground and breaks up the soil. While this is a good thing, to a degree, too much tilling can cause loss of soil.
This loss comes not only from wind and rain but from people. It can be carried off on the tiller, on your boots, and by simply clearing out rows for planting.
14. Floodplain Erosion
Floodplains are the main paths floods take stripping everything along the way. They tend to start as small streams or gullies that erode sideways instead of down into the ground.
They take up miles of space and tend to follow gravity down any kind of grading, no matter how shallow.
15. Coastal Erosion
Erosion of coastlines is caused by wave action. Even the smallest of waves can eat away the soil and loose rock of a coastline drastically changing its shape over time.
During major storms and hurricanes, waves can cause massive landslides and flooding making drastic changes in the coastline.
Prevention of Water Erosion in Farming
The washing away of soil by water is the most common form of erosion in agriculture.
What is soil erosion? It’s the movement of soil from one place to another, usually not where it’s wanted.
The effects of it can be very detrimental. Infertile soil and flooding are the two most damaging, but all effects can be reduced. The following list highlights how to prevent soil erosion in farming where water damage is concerned.
- Plant trees – planting trees native to the area provides roots and leaves to protect areas of loose soil. Leaves keep rain from falling so hard on the ground. Roots hold soil together.
- Plant ground cover – native grasses and low growing shrubs provide stability to soil and protect it from direct rainfall.
- Build retaining walls – build these on slops out of brick, stone, or treated wood as long as it runs along the contour of the ground with just enough slope to keep it from pooling at its center.
- Use mulch – mulch adds weight to soil. Mulch mats can also protect young plants and seedlings on slopes. Another form is logs, made from any kind of fibrous material like straw. Using stakes, you place these on slopes to slow down runoff.
- Use drip irrigation – watering your lawn/garden is like raining on it. Traditional watering methods can cause erosion just like rain. By using drip irrigation, water is delivered in small doses and is able to sink into the ground.
- Reduce/Avoid soil compaction – heavily compacted soil can cause run-off because the water can’t sink into the soil. Compaction is usually caused by walking over the same area all the time. The same goes for heavy machinery use. Establishing set paths for walking and machinery will lessen compaction and prevent erosion.
Prevention of Wind Erosion in Farming
Erosion by wind occurs when vegetation is depleted and the earth is left bare to the forces of the wind.
Below are a few ways to prevent wind erosion in farming.
- Plant vegetation – cultivate the land with either cash or cover crops.
- Cover the soil – spread manure or mulch over bare soil.
- Avoid overgrazing – do not allow animals to eat away grass that holds the soil together. Spots of bare soil when animals are grazing is a sure sign of overgrazing.
- Prevent water erosion – heavy showers or overwatering can leave the soil bare which becomes vulnerable to gusty winds when it is dry.
As you can see, erosion mainly has natural causes, but even so in most cases, we humans can help prevent it and lessen its impact on our landscape.