Grade 6 Agriculture Conserving Our Environment – Soil Erosion Control Notes
Soil Erosion Control
Conserving Our Environment — Agriculture (for age 11)
Soil erosion happens when wind or rain washes away the top layer of soil. Good soil is important for growing food. In Kenya, especially in places like the highlands and Rift Valley, farmers use smart ways to stop soil from washing away during the long rains (March–May) and short rains (Oct–Dec).
Why it matters
- Soil gives plants nutrients and water.
- When soil is lost, crops grow poorly and food becomes less.
- Eroded soil can block rivers and make floods worse.
Good to know (Kenya)
- Many small farms on slopes need soil protection.
- Vetiver and napier grass are used on contours to stop runoff.
- Planting trees and cover crops keeps soil healthy.
Simple ways to control soil erosion
- Contour farming: Plant along the curved lines of a slope (contours) so water runs along them and does not wash soil away.
- Terraces and stone walls: Make flat steps on steep land so water slows down. Small stone terraces are common on Kenyan hills.
- Grass strips and vetiver hedges: Plant tall, strong grasses across the slope to catch soil and slow water.
- Mulching: Cover the soil with crop residue, leaves or wood chips to protect soil from raindrops.
- Cover crops: Grow plants like legumes during off-season to protect soil and add nitrogen.
- Agroforestry / Tree planting: Grow trees with crops — tree roots hold the soil and trees give fruit or firewood.
- Avoid overgrazing: Keep animals from eating all the grass. Leave grass to protect soil.
- Gully control: Build small check dams, plant grass, and put stones to stop gullies from getting bigger.
How plants help
Roots hold soil together. Leaves and straw slow rain. Together they protect farms and rivers.
Easy activity — Make a contour line on your school garden
- Find a gentle slope on the school garden.
- Make an A-frame level: use three sticks tied to make an A and hang a string with a small weight in the middle (or use a bottle of water as a level).
- Walk sideways across the slope. Mark places where the string shows level — these points are on the same contour.
- Dig a shallow furrow along the marked points, plant grass or vegetables in the furrow. The furrow will slow water and stop soil from washing away.
What you can do at home
- Plant trees and fruit seedlings (mango, avocado, native trees).
- Keep a compost pile and use compost as mulch.
- Build small terraces or plant napier/vetiver grass on slopes.
School project idea
Create a demonstration plot: one half protected (contours, grass, mulch), the other unprotected. Measure how much soil is lost after rain. Discuss results in class.
Key words
- Erosion: Soil being moved by water or wind.
- Topsoil: The top layer of soil where plants grow best.
- Mulch: Leaves, straw or wood chips that cover soil.
- Contour: A line across a slope that is the same height.
- Terrace: A flat step built into a slope.
Quick fun visual
Mini quiz — try it!
- What does mulch do?
Answer
It covers soil to protect it from rain and keeps moisture in. - Name one grass used in Kenya to stop erosion.
Answer
Vetiver or napier grass. - Why plant trees with crops?
Answer
Tree roots hold soil, give shade, and some give fruit or wood.
Remember: Small changes on farms and in our homes help protect soil, keep rivers clean, and make sure we have food for the future.
Try one idea this week and tell your class what you saw after the next rain!