Soil erosion can be controlled by ploughing across contorous line , reforestation , thin strips of grasses , terrace farming and techniques.

Steps to control soil erosion in hilly areas:

1. Terracing:
- Terracing involves creating steps or flat areas on the slopes of hills to reduce the speed of flowing water and prevent soil erosion.
- This method helps in retaining water in the soil and allows it to percolate slowly, reducing the chances of erosion.

2. Contour ploughing:
- Contour ploughing is a farming practice where the ploughing is done parallel to the contours of the hilly areas.
- This method helps to create ridges and furrows, which act as barriers to water flow, preventing it from gaining excessive speed and causing erosion.

3. Planting vegetation:
- Planting trees, shrubs, and grasses on the slopes of hills helps to control soil erosion.
- The roots of these plants bind the soil particles together, making it difficult for them to be washed away by water.
- Vegetation also helps to slow down the flow of water, allowing it to infiltrate into the soil.

4. Mulching:
- Mulching involves covering the soil surface with organic materials like straw, leaves, or grass clippings.
- This protective layer acts as a barrier against the impact of raindrops, reducing the chances of soil erosion.
- Mulching also helps in retaining moisture in the soil, preventing it from drying out and becoming susceptible to erosion.

5. Retaining walls:
- Building retaining walls along the slopes of hills can help in preventing soil erosion.
- These walls act as barriers, holding the soil in place and preventing it from being washed away.
- Retaining walls can be made using various materials such as stone, concrete, or gabions (wire mesh filled with stones).

6. Construction of check dams:
- Check dams are small barriers built across the flow of water in hilly areas.
- These dams help to slow down the speed of water and store it temporarily, allowing it to percolate into the soil.
- Check dams also help in trapping sediments and preventing them from being carried away by water, reducing soil erosion.

7. Proper drainage system:
- Implementing a well-designed drainage system in hilly areas can help in controlling soil erosion.
- This system includes constructing channels, ditches, and gullies to divert excess water away from the slopes, preventing erosion.

8. Avoid overgrazing:
- Overgrazing by livestock can lead to the removal of vegetation, exposing the soil to erosion.
- Implementing proper grazing management techniques, such as rotational grazing and maintaining proper stocking rates, can help in preventing soil erosion.

9. Soil conservation practices:
- Practices like crop rotation, contour bunding, and strip cropping can help in conserving soil and reducing erosion.
- These practices involve strategically planning the cultivation of different crops and creating barriers to water flow to minimize erosion.

Overall, a combination of these techniques can effectively control soil erosion in hilly areas, preserving the fertility of the soil and ensuring sustainable land management.