This article defines the term ‘irrigation’ and briefly explains its importance with reference to Pakistan. In addition, it also suggests solutions to the problems related to irrigation i.e. waterlogging and salinity in the country.
What does the term ‘irrigation’ refer to?
The term ‘Irrigation’ refers to the artificial supply of water to plants i.e. crops, trees, the man-managed grazing places. More simply, it refers to a temporary supply of water to fields, gardens, etc. for crop farming, tree growing, etc.
What is the importance of irrigation in Pakistan?
Pakistan is an agricultural country. Agriculture provides the largest share of total employment and raw material to different industries. It is the largest source of foreign exchange earnings. It also constitutes the largest share of the total GDP of the country. As the most important sector of the economy, agriculture depends upon irrigation. Because there is scanty rainfall in the country which occurs in the monsoon season. The little rainfall is of less use as it occurs randomly at different times and quantities, thus not suitable for the cultivation of crops. The river and underground water is used for agriculture through different methods e.g. canals, dams, lift and barrage irrigation. Hence irrigation is very important in Pakistan.
Causes of waterlogging and salinity
What is waterlogging?
The term waterlogging refers to an increase in the level of underground water due to continuous seepage of water from perennial canals and fields. This results in the saturation of soil with water making it unfit for crop cultivation and plant growth. Plant roots to a greater o lesser under the soil require air which is prevented to get in because of the presence of water.
What is the problem of salinity?
The underground water that reaches the earth’s surface because of waterlogging also brings different chlorides dissolved in it. This salt is deposited on the surface of the soil as a result of evaporation of this water as it exposes to the sun. This deposition of salt on the surface of the earth is called salinity. An amount of the salt is also brought by irrigation water. The deposition of salt does not allow the growth of plants thus making the soil unfit for crop cultivation.
The deposition of salt inland has adversely affected agricultural production. This problem affects 0.10(1) million acres of land every year. Crops cannot be grown inland with the deposition of salt. This problem reduces cultivable land.
Remedies to overcome waterlogging and salinity
Farmers can adopt the following methods of remedy to get rid of the menace of waterlogging and salinity. They can also be helpful to reclaim land damaged by this agricultural problem.
Installation of Tube wells
Installation of tube wells can help reduce the level of the water table of underground water. A farmer can achieve two important purposes by installing a tube well. Firstly it will bring a reduction in the water table/level of underground water. Secondly, It will provide much-needed water for irrigation and cultivation of crops.
Proper drainage system
As discussed above, one of the causes of waterlogging is the seepage of standing water on the fields into the ground. This seepage of water causes an increase in the water table. By introducing an effective drainage system to drain excess or standing water on the fields can help avoid the seepage of water and waterlogging.
Flushing out the salt
Flushing out the salt is one of the remedies to do away with salinity. Providing extra water during irrigation can flush out soluble salts from the surface of the field. Doing it several times will bring a reduction in the deposition of salt on the field thus making it fit for crop farming. This has been one of the ways to reclaim the salinity hit land in Pakistan.
Repair of canal banks
Water in perennial canals gets leaked from the canal banks and seeps into the ground to cause waterlogging. Regular and periodic repair and effective management of perennial canals can help avoid the problem.