2g & 2h - Soil Erosion & Conservation

What is soil erosion

the process where the top fertile layer (horizon A/topsoil) is lost. Therefore, due to soil erosion, the soil becomes less fertile

What two things can lead to soil erosion

• natural processes

• poor farming methods

Is soil erosion a concern in Malta? Why?

Yes, because in the past 50 years there has been accelerated soil erosion

What are the physical causes of soil erosion

1. Winds: The topsoil along with the organic matter is carried away by strong winds

2. Water: When it rains, soil gets washed away

3. Lack of vegetation: increases soil erosion because there are no roots to hold the soil in place and no plant cover to provide shelter for the soil from wind and rain.

Human causes of soil erosion

1. Deforestation: no leaves to protect soil from rainfall & no roots to hold the soil in place, making it easy for it to be blown or washed away.

2. Ploughing up and down a slope increases soil erosion because water flows downhill more quickly, washing away large amounts of the fertile topsoil.

3. Overgrazing: Too many animals kept in one area which eat all the vegetation and the rest dies off. This causes a lack of vegetation, therefore soil erosion

4. Soil exhaustion: Soil is overused by the growing of too many crops, leading it to eventually become rather infertile so crops can no longer grow. This leads to a lack of vegetation, therefore soil erosion.

5. Collapsed rubble walls lead to soil erosion because they no longer hold the soil in place, allowing rainwater to wash away the fertile topsoil.

6. Urbanisation in rural areas leads to soil loss because vegetation is removed and land is built on, leaving soil exposed to erosion or covered by buildings and roads.

7. Habitat destruction through human activities leads to soil erosion because it removes vegetation from the soil.

How do farmers protect their fields from soil erosion?

• Afforestation (planting more trees) - like Forests 2000

• Controlled grazing (restrict amount of animals on a field)

• Crop rotation - Crop rotation replaces nutrients in the soil, helping it stay fertile and healthy + vegetation = no soil erosion

• Contour ploughing (opposite of up and down ploughing. This slows down rainwater moving down the slope which carries soil with it.

• Terrace fields & Rubble walls (built at the edge of each field and help keep soil on place and let excess water drain through the wall, preventing soil erosion)

• Irrigation methods: drip & sprinkler - deliver water to plants, helping them grow and & prevent surface runoff.

What are the SDGs (sustainable development goals) that are related to soil.

• SDG 11 - Sustainable Cities & Communities (Soil conservation helps cities grow, making sure there is enough food for everyone & also create green spaces making cities healthier and more enjoyable)

• SDG 13 - Climate Action (healthy soil acts as a carbon sink, therefore taking care of soil reduces carbon emissions, which are a great contributor to climate change)

• SDG 15 - Life on Land (Healthy soil protects habitats for plants and animals, supporting biodiversity and the sustainable use of land.)