What is the problem with soil erosion?Soil erosion is bad for the environment, so we are testing different ways to prevent it.Soil erosion washes away our needed soil we use to grow crops and can reveal plant roots  once it gets washed away into the ocean.Our hypothesis is that the rocks will hold back soil erosion from taking place the most. We say rocks because they weigh more and that will make the soil more compressed so it can prevent too much soil from getting washed away. 

 

 

 

 

What is Soil Erosion?

Soil erosion is the process where the top layer of soil which is known as topsoil gets washed off by wind, water, or human actions.

 

How do you know that erosion has taken place?

• The wind is dusty
• Glacial ice looks muddy
• The water looks muddy  and bits of brown rocks and soil can be found in the water

 

 

How does soil erosion happen?

 

Types of Erosion

Physical erosion

Physical erosion is a process of rocks changing their physical properties without changing their physical chemicals. They get smaller and smoother in size due to erosion.

 

Erosion by water

Water erosion is when rain, rivers, floods, lakes, and the ocean wash away soil, sand, and sediments.

 

Erosion by wind

Wind is a powerful agent of erosion. Dust, sand, and/or ash are constantly transported from one place to another due to wind.

 

Erosion by Ice

Over time, Ice in the form of glaciers, moves slowly downhill carrying tiny rocks, sand, and huge boulders. In the process, they grind the rocks scrape away the soil, and create major changes to the landscape.

 

Erosion by human actions

Human activities such as overgrazing (stocking too many animals such as sheep, cattle, or goats on farmlands), cropping, and deforestation cause soil to become loose and cause landslides.

 

Other factors of erosion

Natural factors such as climate, topography (surface features of an area), vegetation, and tectonic activity also cause erosion.

 

Reference:

https://education.nationalgeographic.org

 

 

 

How does soil erosion affect us?

• In the past 150 years, half the planet’s topsoil has been lost due to erosion. The topsoil carries a lot of nutrients. The loss of it has affected the soil quality and has hurt agriculture delivering poor quality and unhealthy crops.

• Soil erosion goes beyond the loss of fertile land. It increases pollution and sedimentation in streams.

• Sedimentation clogs the waterways and destroys the natural habitats of species such as fish and other animals.

• Degraded lands often hold on to less water which can worsen flooding and also alter the water flow.

• Erosion can change the landform and cause loss and desertification of valuable land.

 

 

How can we prevent soil erosion?

 

Plant grass and shrubs (ornamental grass, turf and shrubs)

Roots will hold soil together and the leaves will block the rain from breaking the soil into particles and getting washed away.

Mulch matting

Use a mulch mat and cover seeds and young plants to hold the vegetation

 

Lay fiber logs

Use logs or “wattles” made from fibrous materials like straw to slow water running down steep slopes. Seeds can be planted directly in a log.

 

Building retaining walls

A retaining wall at the base of a slope can block the soil from collapsing.

 

Improve drainage

Buildings should have gutters/water pipes so that they can drain excess water out of gardens effectively, during heavy rainfall so that the topsoil does not get washed away.                                            

 

Reduce watering

Using less water to water plants helps prevent too much soil erosion. Drip systems can be installed to deliver small amounts of water to plants.

 

Avoiding soil compaction

When people, animals, or machines move over soil, it gets compacted into a dense layer. This will lead to less space between soil particles. The water that runs over the compacted soil will not have proper drainage and will flow down eroding the surface soil.

Plant trees to prevent landslides

Forestation is one of the best ways to prevent soil erosion.

 

Reduce tillage

Tilling creates a top layer of compact soil. Loose soil can easily be blown off by the wind.

 

Protect weak crops with strip cropping

Crops with weak roots must be distributed and planted in strips along with erosion-resistant crops like dense grass to prevent erosion.

 

 

 

 

 

 

 

 

 

 

 

 

 

We will change the type of item we use for each bottle. We will use soil and Plant structure, soil and rocks and bare soil to check which one prevents soil erosion the best.

Independent/Manipulated Variable: Type of ground covering (bare soil, grass/plant, rocks)

 

Dependent/Responding Variable: The amount of soil/dirt collected in the mineral water bottles.

 

Controlled Variables (for each controlled variable listed, tell how you are going to control it):

 

Same sized Pop bottles (3, four litre Pop bottles)

Same sized mineral water bottles (3)

Same amount of soil

Same dimensions of the hole cut in each pop bottle 

Same height in each of the three  mineral water bottles

Same amount of water poured at the same pressure

 

We will have 3 bottles filled up with soil and different materials to prevent erosion from taking place. We will have a bucket attached to the top of the lid to collect the water from the process of soil erosion. We will see how much water has been collected in each bottle to determine which material helps prevent soil erosion the best.

Step 1: Take 3 empty 4L Pop bottles and cut an equal size rectangular hole (7cm x 25cm)on top of each of them.

 

Step 2: Take a large rectangular cardboard box and place the 3 Pop bottles at equal distance from each other and paste them on to the box to secure them. Make three holes on the side edge of the cardboard box so that the bottlenecks can protrude from them.

Step 3: Take 3 transparent mineral water bottles. Cut the top part off horizontally, so that about ¾ of the bottle remains. Make two holes on either side of the cropped mineral water bottles and hang a wire connecting one hole to the other making it look like a bucket. Hang the three mineral water bottles onto the bottlenecks of the large Pop bottles that are protruding from the cardboard box. The mineral water bottles should hang outside on the bottlenecks.

 

Step 4: Fill all 3 Pop bottles with equal amounts of garden soil.  Number the bottles. Leave the first with just bare soil.  Cover the second with grass/plants and the third with rocks.

 

Step 5: Very slowly pour equal amounts of water from the furthest end of the pop bottles. 

 

Step 6: Observe the quantity of soil and the color of the water that drains into the mineral water bottles.

 

1. When the water is being poured into the different bottles with soil, plants, and rocks we will observe the amount of water poured into each cup. The amount of water that is poured into each cup will help us figure out which material helped prevent soil erosion the most.

2. When we poured the water into the black earth soil, Topsoil and Clay soil (it is bare soil) and observed that the black and topsoil eroded easily and the colour of the water was dark brown. These two types of soil had very little difference in the colour of the water. However, the clay had the clearest water because the texture was chunky and glued together so that water did not get absorbed in. 

3. Next, we wanted to try out putting rocks on the black earth soil, and some mulch on the topsoil to see if it would make a difference when we poured the water in. The black earth had the muddiest water, the topsoil with mulch had a lighter shade of brown while the clay was the clearest out of them all. 

4. We observed that when the soil particles don't have much room to absorb water such as in clay soil the water just gushes through but does not carry much soil with it. We also observed that ground coverings such as rocks and mulch can act as a barrier for water to seep through into the soil and will minamize erosion. Certain types of soil can erode more than others depending on some of their textures.

In our earlier experiment we used the same type of soil with coverings such as artificial grass and rocks. One bottle contained bare soil with no protection on it. In this experiment we noticed that the bare soil got washed away very easily since as it had no protection to keep the soil from getting washed away. The bottle that contained the grass had the clearest water, while the one with the rocks had less muddier water. We observed that grass was the best option for minimizing soil erosion.

First we start off with putting soil in a bottle, then we put different materials to test which one best prevents erosion. Then we slowly pour equal amounts of water into each bottle. The water causes erosion to take place to wash away the soil and make its way through the barricades of the materials we used. The amount of water that passes through the plants and rocks and falls into the cup will determine which one works better for preventing erosion from washing away the top layer of soil. 

When we compared the first and second experiments we came to the conclusion that the grass was the best coverage to prevent soil erosion.

You can use soil erosion in real life when you are at a beach and you see that the water is taking up more land than it is supposed to so you could use big heavy rocks because they're the ones that stay up the best and the soil didn't go through as much as it did with the artificial grass and the Bare dirt.

Soil erosion is a natural phenomenon and it can happen anywhere. Water, wind an human actions are agents of erosion. When these agents become powerful then, the top part of the soil which carries nutrients can easily get washed off. By understanding different kinds of soil and by applying solid ground coverings we can minamize erosion.

-When we didnt have the same sized bottle

-The wire wasnt long enough to be attached to the bottle to catch the eroded water

-The quantities of ground coverings we put in the bottles may have varied

-Measuring the quantity of soil / level may have been flawed 

-Put too much water into one bottle

Sources:

https://education.nationalgeographic.org

https://www.wikihow.com

https://www.worldwildlife.org

pictures taken from shutterstock.com

We now acknowledge that soil erosion is bad for the environment because it washes away the nutrients in the soil we use to grow crops and plants and other things. It also washes leaves the roots of  the plants bare and unhealthy. Crops also turn out to be less and unhealthy.