Question

Give reasons for the following.

Canal irrigation leads to the land around it becoming unproductive.

Answer 1

1. Seepage from unlined canals continuously drains massive amounts of water into adjacent fields, causing the subsurface water table to rise dramatically.
2. Widespread waterlogging occurs when the higher water table saturates the soil pores, entirely cutting off the oxygen supply to crop roots.
3. Capillary action transports dissolved subterranean minerals and toxic salts from deep underground to the upper layers of the soil.
4. Land salinisation is a serious environmental issue caused by intense sun evaporation, which leaves thick, toxic salt crusts on the surface.
5. Altered chemical soil balance causes the land to become extremely alkaline or acidic, permanently diminishing soil fertility and making it unsuitable for future cultivation.