Reclamation of Salt Effected Soils and management of saline soils
Reclamation of Salt Effected Soils:
Introduction of canal irrigation accelerated the appearance of salt in those places where they had existed at some depth in the soil profile. The gestation period between canal irrigation and appearance of water logging and salinity was rather small. While canal irrigation may salinize the soil through rise in water table well water irrigation usually cause salt building due to poor quality of water. While incomplete weathering of constituent soil mineral ensure a steady source of salts. The inadequate rainfall favors their deposition in the surface layers in dry lands. a recent estimate shows that about 10- M ha. Soil is affected by salinity and alkalinity.
Removal of excess salts from the saline soils accomplished by simple leaching provided good quality water is available for the purpose and water table is either reasonably deep or there is procision of subsurface drainage. In dry lands with saline ground water or where salinity is associated with water logging, immediate reclamation may not be possible the best alternative is to sow such lands with salt tolerate crops. Like Atripex, Laptochola.
Management of Coastal Saline Soils:
Technology for management of these soils needs both Government and community participation: The technology include provision of embankment with one way sluice gate to prevent the ingress of sea water into land, at the same time draing the excess rain water from inlands in to the sea provision for the rain water storage from the late monsoon rains for irrigation in the winter season and provision for surface and subsurface open drains with pumps, clever ever necessary.
Desetifiaction and Arid Soils:
the arid zone of India occupies about 12% of the geographical area and is best with desertification hazards due to very high human and live stock pressure. For rangeland improvement following technologies are suggested.
1. Contour furrow (60 cm wide and 22 cm deep) on range lands at a distance of 8 – 10 meter across the slope for moisture conservation.
2. Inter row water harvesting in which 30 – cm. wide ditches alternated with 70 cm wide raised beds are prepared.
3. Planting of improved grasses like Cenchrus Ciliaris for high forage yields on sandy soils with 250 mm, annual rainfall.
4. Introduction of Stylosanthes hamates after lands leveling for improvement of productive of grasslands.
5. Following Agri- pasture system.
6. Introduction of forage trees like Acacia Senegal, Acacia nilotica.
Management of Water Resources:
considering the fact that 80 -90 % of the developed water resources are diverted towards irrigated agriculture. Its efficient management is of crucial importance. The efficiency of different irrigation projects vary from 14- 40 % conveyance losses vary from 22- 50 % depending upon the location and management level. Following sustainable recommendation have been evolved for efficient for efficient use of irrigation water.
1. On farm water management technology pipes/ or prefabricated channel to prevent seepage losses.
2. Scientific scheduling of irrigation both for adequate or deficient water supplies.
3. Furrow, alternate furrow, skips furrow irrigation. For all row crops.
4. Introduction of sprinkler and drip irrigation system in water scarcity areas.
5. Conjunctive use of surface and ground water and canal and tank water to solve drainage problems.
6. Provision of drainage facilities in canal and in tank command area for increasing the productive of crops.
7. Adopting proper cropping system in place of continues low land paddy.
8. Integrated watershed development tio use rainwater, soil water, ground water and runoff water efficiently.
8. Rechardng ground water during rainy season through season through basis, recharge wells diversions of water to store on lands and by construction of check dams and percolation ponds.
It is better strategy to increase irrigated area than to increase irrigation intensity, inadequate control over irrigation water; poor timing and allocation of irrigation water are serious limitation in efficient management of water for irrigation projects.