Soil and Water Conservation: notes

Erosion

• Erosion: soil carried away by water or wind.
• Types: sheet erosion removes a thin layer evenly; rill erosion makes small channels; gully erosion makes deep channels; wind erosion blows dry topsoil.
• Causes: bare ground, overgrazing, ploughing up and down a slope, cutting trees.

Control

• Contour ridges: ridges across the slope that slow runoff.
• Terraces: flat steps cut into steep land.
• Mulching: a cover of dry plant material that protects soil and keeps moisture.
• Strip cropping and cover crops: keep the ground covered.
• Gullies: block with stones and brushwood, then plant grass.

Irrigation

• Flood: water covers the field. Uses a lot of water.
• Furrow: water runs in small channels between rows.
• Sprinkler: water falls like rain.
• Drip: water drips at the plant root. Saves the most water.