Pakistan is basically an agricultural country and irrigation is the lifehood of agriculture. Pakistan’s agriculture is classified as irrigated agriculture with about 18 million hectares (Mha) of irrigated area contributing 90% of total agricultural produce. The area with potential for agricultural productions if water is made available for 26 Mha. Despite enormous losses in the irrigation system and reduced supplies due to prolonged drought and reduced river flow the farmers are still using highly inefficient and obsolete methods of irrigation.
Irrigations practices followed in the Balochistan Province are primitive and highly inefficient. Orchards and Fruits Farms in particular are irrigated by flooding entire fields which reduces water use efficiency to less than 40% from water source to crop use. There is immense need to save water due to severe water crises being faced by the country.
The demand of irrigation is increasing day by day due to increase in population. Chaudary and Ali 1989 expressed that overall scarcity of water, non availability of water at the right time and inefficient utilization of available water appear to be the leading factors restricting expansion in irrigated acreage and causing the gap between actual and potential yields level. At presents the irrigation water application practices are based on the traditional methods and the delivery and application efficiencies especially at the farm level are quite low.
The Indus basin irrigation system is operating at less than 40% efficiency. The shortages of irrigation water particularly during critical crop growth stages (milking and grain forming) significantly affect the crop yields. WAPDA 1995 observed that the availability of canal water supplies also significantly vary over the year and do not match wit the water requirements at various stages of crop development. Storing of surplus canal water during slack irrigation season or catching excess rainfall in a storage reservoir and subsequently using it with sprinkle and trickle irrigation will help the farms to irrigate elevated crop lands.
About 6.0mha Barani areas of the country lack any regular irrigation facilities. The reason for not having irrigation facilities is that the traditional gravity flow irrigation system is not possible due to topography, soil type, shortage of water etc. when water for irrigation is in small quantity, the more efficient use of water becomes necessary. The efficient utilization of irrigation water is possible by adapting pressurized irrigation systems such as sprinkle and trickle irrigation.
These modern irrigation technologies for the field crops and orchards can help increase water use efficiencies to 90%. Though capital intensive, the future of irrigated agriculture in Pakistan depends on adopting theses technologies for crop production as water is becoming an ever- increasing hard-to-get resources and the gap between demand and supply widens.
The term modern technology in relation to irrigation usually refers to on-farm irrigation system such as sprinkle and trickle irrigation. It can also mean the introduction of piped distribution systems for surface irrigation as well as the use of treadle pumps or the use of petrol and diesel driven pumps in areas where such technology is not used.
Sprinkle irrigation is used on approximately 5 percent of irrigated land throughout the world, the majority of which is in the developed countries. It is unlikely to replace the large areas under surface irrigation (essentially the remaining 95 percent except for a small amount of trickle irrigation.
Sprinkle is potentially less wasteful of water and uses less labor than surface irrigation. It can be adapted more easily to sandy soils subject to erosion on undulating ground, which may be costly to re-grade for surface methods. There are many types of sprinkle systems available to suit a wide variety of operating conditions. The most common for smallholders is a system using portable pipes (aluminum or plastic) supplying small rotary impact sprinklers.
The cps (center pivot system) is at the forefront which can irrigate up to 100 ha at a time. In the UK, USA, LIBYA and Kingdom of Saudi Arabia the farmers are using these system for irrigating large desert area. They are taking a lot of profit with minimum cost input. In most developing countries technicians and farmers do this very successfully in the private sectors. This technology can be very adaptable and can be used in the innovative ways when the conditions are right.
Irrigations practices followed in the Balochistan Province are primitive and highly inefficient. Orchards and Fruits Farms in particular are irrigated by flooding entire fields which reduces water use efficiency to less than 40% from water source to crop use. There is immense need to save water due to severe water crises being faced by the country.
The demand of irrigation is increasing day by day due to increase in population. Chaudary and Ali 1989 expressed that overall scarcity of water, non availability of water at the right time and inefficient utilization of available water appear to be the leading factors restricting expansion in irrigated acreage and causing the gap between actual and potential yields level. At presents the irrigation water application practices are based on the traditional methods and the delivery and application efficiencies especially at the farm level are quite low.
The Indus basin irrigation system is operating at less than 40% efficiency. The shortages of irrigation water particularly during critical crop growth stages (milking and grain forming) significantly affect the crop yields. WAPDA 1995 observed that the availability of canal water supplies also significantly vary over the year and do not match wit the water requirements at various stages of crop development. Storing of surplus canal water during slack irrigation season or catching excess rainfall in a storage reservoir and subsequently using it with sprinkle and trickle irrigation will help the farms to irrigate elevated crop lands.
About 6.0mha Barani areas of the country lack any regular irrigation facilities. The reason for not having irrigation facilities is that the traditional gravity flow irrigation system is not possible due to topography, soil type, shortage of water etc. when water for irrigation is in small quantity, the more efficient use of water becomes necessary. The efficient utilization of irrigation water is possible by adapting pressurized irrigation systems such as sprinkle and trickle irrigation.
These modern irrigation technologies for the field crops and orchards can help increase water use efficiencies to 90%. Though capital intensive, the future of irrigated agriculture in Pakistan depends on adopting theses technologies for crop production as water is becoming an ever- increasing hard-to-get resources and the gap between demand and supply widens.
The term modern technology in relation to irrigation usually refers to on-farm irrigation system such as sprinkle and trickle irrigation. It can also mean the introduction of piped distribution systems for surface irrigation as well as the use of treadle pumps or the use of petrol and diesel driven pumps in areas where such technology is not used.
Sprinkle irrigation is used on approximately 5 percent of irrigated land throughout the world, the majority of which is in the developed countries. It is unlikely to replace the large areas under surface irrigation (essentially the remaining 95 percent except for a small amount of trickle irrigation.
Sprinkle is potentially less wasteful of water and uses less labor than surface irrigation. It can be adapted more easily to sandy soils subject to erosion on undulating ground, which may be costly to re-grade for surface methods. There are many types of sprinkle systems available to suit a wide variety of operating conditions. The most common for smallholders is a system using portable pipes (aluminum or plastic) supplying small rotary impact sprinklers.
The cps (center pivot system) is at the forefront which can irrigate up to 100 ha at a time. In the UK, USA, LIBYA and Kingdom of Saudi Arabia the farmers are using these system for irrigating large desert area. They are taking a lot of profit with minimum cost input. In most developing countries technicians and farmers do this very successfully in the private sectors. This technology can be very adaptable and can be used in the innovative ways when the conditions are right.
Trickle or drip irrigation comprises a system of pipes and emitters that can deliver small frequent irrigations to individual plants. This technology can provide farmers with a method of precise control over the timing and amount of irrigation and so they can easily meet the crop water demand without wasting water. Wastage of water occurs only if the system is left running for too long or there are leaks in the pipes due to hiring unskilled persons, or the less quality materials fittings. Trickle irrigation is not yet widely used on a world scale and covers less than 0.1 percent of irrigated land.
Claims made about crop yields and water savings need to be judged with care. Sales people often imply there is a magic about trickle irrigation when they refer to substantial increases in the yield and savings in water use. There is no magic. Crops respond primarily to water and not so much to the method of application. They need the same amount of water to grow properly whether this is applied with trickle irrigation or with surface flooding methods. If the right amount of water is applied to the crop at the right time it will flourish. Similarly, water savings can only be made by reducing wastage and not by reducing the amount of water the crop needs. Ironically many farmers end up applying more water when using trickle irrigation because the system allows them to apply water more easily than with other methods.
A major technical problem with trickle irrigation is emitter and lateral blockage from sand and silt, chemical precipitation from ground and algae from surface water. Each of the problems takes the use of trickle into a level of technology and support that can be difficult to sustain in a developing country. However, on a small scale the farmer can simply go around and clean the system regularly, which can overcome these problems. On a larger this would not be practicable.
Smallholders are encouraged in adopting the trickle system in the subcontinent as the spare parts are available local. The trickle system is easily operated by switched off. The potential for making timely and adequate irrigation as well as for reducing water wastage is good and the challenge is to realize that potential.
A critical issue for smallholders is the cost of trickle irrigation. The cost may well be justified by improved crop production and hence financial returns for farmers.
The system cost is determined by crop type, row spacing and the total field area irrigated. System cost can range from US$ 1000- 3000 per ha (Cornish 1998). In addition the system require regular cleaning, skilled management for effective operation and maintenance – filters require regular cleaning, systems may require periodic flushing to prevent build-up of slime. Equipment must be regularly inspected to identify and replace damaged components.
Claims made about crop yields and water savings need to be judged with care. Sales people often imply there is a magic about trickle irrigation when they refer to substantial increases in the yield and savings in water use. There is no magic. Crops respond primarily to water and not so much to the method of application. They need the same amount of water to grow properly whether this is applied with trickle irrigation or with surface flooding methods. If the right amount of water is applied to the crop at the right time it will flourish. Similarly, water savings can only be made by reducing wastage and not by reducing the amount of water the crop needs. Ironically many farmers end up applying more water when using trickle irrigation because the system allows them to apply water more easily than with other methods.
A major technical problem with trickle irrigation is emitter and lateral blockage from sand and silt, chemical precipitation from ground and algae from surface water. Each of the problems takes the use of trickle into a level of technology and support that can be difficult to sustain in a developing country. However, on a small scale the farmer can simply go around and clean the system regularly, which can overcome these problems. On a larger this would not be practicable.
Smallholders are encouraged in adopting the trickle system in the subcontinent as the spare parts are available local. The trickle system is easily operated by switched off. The potential for making timely and adequate irrigation as well as for reducing water wastage is good and the challenge is to realize that potential.
A critical issue for smallholders is the cost of trickle irrigation. The cost may well be justified by improved crop production and hence financial returns for farmers.
The system cost is determined by crop type, row spacing and the total field area irrigated. System cost can range from US$ 1000- 3000 per ha (Cornish 1998). In addition the system require regular cleaning, skilled management for effective operation and maintenance – filters require regular cleaning, systems may require periodic flushing to prevent build-up of slime. Equipment must be regularly inspected to identify and replace damaged components.
