(a) Distinguish between irrigation and drainage (b) State and explain four systems of irrigation and two of drainage.

Answer Details

a) Irrigation and drainage are two distinct processes in agriculture. Irrigation is the process of applying water to plants through various methods to supplement natural rainfall and ensure optimal plant growth and yield. On the other hand, drainage is the process of removing excess water from the soil or land to prevent waterlogging, soil salinity, and other problems that can lead to poor plant growth.

b) There are several systems of irrigation and drainage, and some of them are:

Systems of Irrigation:

1. Flood Irrigation: In this system, water is allowed to flood the entire field, and it is left to infiltrate the soil by gravity. It is a traditional and less efficient method of irrigation.
2. Sprinkler Irrigation: This system involves the use of sprinklers to distribute water on the plant leaves or over the field. Water is delivered to the plants in a spray-like manner, which simulates rainfall. It is suitable for areas with high temperatures and low humidity.
3. Drip Irrigation: In this system, water is applied slowly and directly to the root zone of plants. Water is delivered to the plants through a network of pipes and emitters that release water in droplets. It is a highly efficient irrigation method that saves water and energy.
4. Center Pivot Irrigation: This is a mechanized irrigation system that involves the use of a large sprinkler that rotates around a pivot point. Water is sprayed over the field as the sprinkler moves in a circular pattern. It is ideal for large, flat fields.

Systems of Drainage:

1. Surface Drainage: This system involves the use of surface channels or ditches to remove excess water from the land surface. It is useful in flat areas with poor drainage.
2. Subsurface Drainage: In this system, pipes or drain tiles are installed beneath the soil surface to remove excess water from the soil profile. It is useful in areas with high water tables and heavy soils that are prone to waterlogging.

In summary, irrigation involves the application of water to plants, while drainage involves the removal of excess water from the soil. Flood, sprinkler, drip, and center pivot irrigation are some of the systems of irrigation, while surface and subsurface drainage are some of the systems of drainage.