Theory question 104
Irrigation and Drainage(a)(i) Explain the term surface drainage. (ii) List three disadvantages of surface drainage.
(b)(i) Define irrigation (ii) State two aims of irrigation (iii) List five problems associated with irrigation.
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(a)(i) Surface drainage is removal of excess water from the land surface through open ditches, channels or furrows
(ii) Any three: ditches take up farmland; hinder movement of machines; need frequent clearing (weeds, silt); cause erosion of channel banks; breeding sites for mosquitoes and snails
(b)(i) Irrigation is the artificial application of water to land for crop production
(ii) Any two: supply water when rain is not enough; allow all-year/dry-season farming; increase yields; soften soil for tillage; leach out salts
(iii) Any five: salinity; waterlogging; high cost; water-borne diseases; erosion; leaching of nutrients; weed growth; scarcity of water; need for skilled labour
Answer each sub-part separately.