Science · Class 7
Soil
Soil profile, types, moisture, and soil conservation.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Soil forms by weathering of rocks over thousands of years. This chapter covers soil profile horizons, types (sandy, clayey, loamy), percolation, moisture, and soil conservation methods.
Soil Profile
- O-horizon: humus and organic matter
- A-horizon (topsoil): minerals + humus — most fertile
- B-horizon: minerals leached down
- Bedrock: parent rock
Soil Types
- Sandy: large particles, high percolation, low water retention
- Clayey: tiny particles, sticky, poor drainage
- Loamy: best for crops — sand + clay + humus balance
Soil Conservation
- Crop rotation, terrace farming, shelter belts
- Avoid overgrazing and deforestation
- Mulching retains moisture
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Percolation
Which soil type has highest percolation rate?
- 1Sandy — large spaces between particles
- 2Water drains quickly
- 3Clayey has lowest percolation
Answer
Sandy soil
Soil erosion
How do trees prevent soil erosion?
- 1Roots bind soil particles
- 2Canopy reduces rain impact
- 3Leaf litter adds humus
Answer
Root network holds soil
Key Points to Remember
- ✓ Humus makes soil fertile and dark
- ✓ Earthworms are friends of farmers
- ✓ Soil is a precious natural resource
Exam Tips
- • Draw soil profile with horizons labelled
- • Compare sandy, clayey, loamy soil
- • List soil conservation practices
Practice MCQs — Soil
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Topsoil is richest in: