GRADE 8 Agriculture CONSERVING AGRICULTURAL ENVIRONMENT – Soil conservation measures Notes
CONSERVING AGRICULTURAL ENVIRONMENT
Subtopic: Soil conservation measures
Audience: Kenyan learners (age ~13). This page explains easy, useful ways farmers and schools can protect soil so crops grow well now and in the future.
Why conserve soil? 🌱
- Soil gives plants water and food. If soil washes away or loses nutrients, crops fail.
- Soil conservation keeps farms productive, saves money and protects rivers and lakes from silt.
- Good soil helps feed families and keeps Kenyan landscapes healthy (highlands, rangelands, riverbanks).
Common causes of soil loss in Kenya
- Heavy rains on steep slopes (e.g. Rift Valley, highlands) causing runoff.
- Deforestation and removing vegetation cover.
- Overgrazing by livestock.
- Poor farming methods (ploughing up and down a slope, leaving soil bare).
Important soil conservation measures (simple and used in Kenya)
Plant and plough along the contour lines (level lines) of a slope. This slows water and reduces soil washing away. On steep slopes, stone or earthen terraces (fanya juu / fanya chini) are built — common in Kenyan highlands.
Plant trees and shrubs with crops. Roots hold soil. Shade reduces evaporation. Use species like Faidherbia (when suitable) and local shrubs. Contour hedgerows (lines of grass or shrubs) form barriers to stop runoff.
Grow cover crops (legumes like desmodium or cowpeas) or use crop residues as mulch. These protect soil from rain and add organic matter.
Change the crops grown in a field each season (e.g., maize then beans). This keeps soil healthy and reduces pests. Intercropping (two crops together) uses space well and keeps soil covered.
Add compost, farmyard manure, or plant residues. This improves soil structure and holds water. Do not burn crop residues.
Fix gullies quickly by planting vetiver grass, building small stone or log check dams and replanting vegetation. This prevents large soil loss.
Plant rows of trees or shrubs to block strong winds that blow topsoil away in dry areas.
Simple diagrams (visuals)
_________
| crop |_____
|_______| |
| crop |_____| <-- terraces hold soil and water
|_______|
How students and schools can help
- Start a school garden using mulching, compost, and crop rotation.
- Plant trees (fruit or native species) along boundaries as windbreaks.
- Join community projects to repair gullies and build terraces.
- Teach others: create posters that explain why soil matters.
Quick do's and don'ts ✅❌
- Cover soil with plants or mulch.
- Use contour planting on slopes.
- Add compost and manure regularly.
- Leave fields bare between seasons.
- Overgraze the same area without rest.
- Burn crop residues (it kills soil life).
Short review questions
- Name two soil conservation methods used on slopes in Kenya.
- Why are cover crops good for the soil?
- What can your school do to help stop soil erosion?
Sources: Common Kenyan farming practices and conservation ideas used by smallholder farmers and school projects.