In canal areas there is tendency of farmers to over irrigate, following are the other causes of excess use of water.
- Tendency of the cultivator to over irrigation of his fields.
- Water is not charged on volumetric basis and hence there is no incentive to use it economically.
- No attention is paid beyond distributory outlets to breaches in the bunds and water flowing out, because there is no penalty for such breaches.
- Watercourses beyond distributory outlets are not given proper grade and water runs too fast causing soil erosion, wastage of water and water logging.
Excess water cause water logging conditions, soil may be ill drained and causes following harmful effects.
- In low lying areas excess water if cannot be carried away as surface runoff causes water logged condition which affects aeration and soil temperature.
- The fine texture soils due to poor permeability the water cannot move downward fast enough and accumulates on the surface, obstructing aeration. In sandy soil if heavy irrigation is given the water will rapidly percolate down and will be wasted.
- The water table may be high and the additional water accumulates and chokes the air spaces and saturates the surface and sub-soil.
- Many toxic salts affecting water absorption by roots and causes damage to crops.
- Agricultural operation viz. inter cultivation cannot be carried out properly.
- Weeds, which compete for nutrients, space and light, grow rapidly and interfere, crop growth and cultural operations.
- Due to excess water soil structure get affected.
Ag.
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