Water Supply, Irrigation and Drainage: Drainage - Form 1 Agriculture Note

• Drainage
  • Importance of Drainage as a Method of Land Reclamation
  • Methods of Drainage
• Water Pollution
  • Agricultural Practices Which Pollute Water
  • Methods of Preventing Water Pollution

Drainage

- This is a method of removing excess water or lowering the water table from a marshy water-logged land.

- It is also a method of land reclamation.

Importance of Drainage as a Method of Land Reclamation

• To increase soil aeration.
• To raise soil temperature.
• To increase microbial activities in the soil.
• To reduce toxic substances from the soil.
• To increase soil volume for exploitation by plant roots.

Methods of Drainage

• Use of open ditches.
• Use of underground drain pipes.
• French drains.
• Cambered beds.
• Pumping out water from the soil.
• Planting tree species which absorb a lot of water for example eucalyptus.

Water Pollution

• This is the process by which harmful substances get into the water.
• The harmful substance is referred to as a pollutant.

Agricultural Practices Which Pollute Water Include:

• Use of inorganic fertilizers.
• Use of pesticides.
• Poor cultivation practices such as over cultivation, cultivating along the river banks.
• Overgrazing which leads to erosion of soil thus causing siltation in water sources.

Methods of Preventing Water Pollution

• Soil conservation measures which minimize soil losses through erosion.
• Fencing off the water sources.
• Adopting organic farming practices for example controlling pests and weed using non-chemical techniques.
• Planting grass along river banks to minimize siltation in rivers.
• Proper disposal of empty chemical containers.