Theory question 103
Irrigation and Drainage(a) Define the term Irrigation.
(b) List six sources of water for irrigation.
(c) Give three reasons why irrigation schemes are necessary in Nigeria.
(d) State two similarities and three differences between sprinkler and surface irrigation.
Show the model answer
(a) Irrigation is the artificial supply of water to soil for crop growth
(b) Any six: rivers; streams; lakes; dams/reservoirs; wells/boreholes; ponds; springs; rain-water harvesting tanks
(c) Any three: rainfall is seasonal and unreliable, especially in the north; allows dry-season (all-year) cropping; increases yields; allows early planting; supports crops with high water needs (rice, vegetables); food security
(d) Similarities: both are artificial ways of applying water to crops; both need a water source (and often a pump) and planning/management
Differences: surface is cheaper, sprinkler expensive; surface needs level or gently sloping land, sprinkler suits any slope; surface wastes more water, sprinkler uses water efficiently; sprinkler needs pressure/pumps and pipes, surface uses gravity channels; surface may cause waterlogging and salinity
Answer every part; differences are best in a table.