It is well established fact that irrigation water is the most critical factor in crop production and its efficient use enhances productivity of other non-water inputs as well. The Punjab is facing severe shortage of irrigation water for many years and on the other hand, there is inefficient use of available resources. The same is resulting in much lower agricultural productivity from highly productive resource base of the province. High efficiency irrigation systems (HEIS) have been found water and nutrient efficient and most appropriate option to address various crop production issues.
Types of HEIS
Drip, bubbler, conventional sprinkler, rain-gun, center pivot etc. are together referred to as high efficiency irrigation systems (HEISs) which use pipes for conveyance of water from the source to points of use. In drip or trickle irrigation, water is provided to individual plants by means of small emitters in the form of droplets. Bubbler irrigation is very similar to trickle irrigation except that the water is delivered to the plants through micro sprinklers mounted on small spikes. In rain-gun irrigation systems, water is pumped at high pressure through a piped system and sprayed over the field.
Drip Irrigation System
Drip irrigation also called as trickle/micro irrigation is the most efficient technology that makes highly effective use of water, fertilizers, and nutrients. Its main principle is to apply water and other inputs slowly, regularly, and frequently as close to the plant roots as possible through emitters installed on plastic pipes laid out in the field. Regular and timely availability of nutrients throughout the plant growth period as per exact requirements and maintenance of favorable soil moisture conditions facilitate to maximize crop productivity. Drip irrigation technology is best suited for orchards and high value row crops such as cotton, maize, sugarcane, vegetables etc. It has become the most valued innovation, which optimizes use of water and fertilizers by enhancing the irrigation efficiency as much as 95 percent.
Sprinkler Irrigation System
The sprinkler system is the overhead irrigation whereby water is sprayed on the soil/crop somewhat like rain. A typical sprinkling unit comprises of an electric or diesel pumping unit, a portable or buried main pipeline with hydrants at predetermined intervals, and one or more sprinkler units attached to hydrants or hose. Sprinkler systems are classified into various types on the basis of their spray pattern and mobility/portability
Schematic Diagram of Pressurized Irrigation System
Basic field layout of High Efficiency (pressurized) Irrigation System is shown below:
Cost Sharing Arrangements
The government subsidizes 60 percent of total system cost for installation of HEIS on upto 15 acres while the remaining costs are contributed by the beneficiary farmers. In addition, government provides 60 percent of scheme cost for construction of water storage pond, if needed, on the basis of site specific technical requirements.
An impact assessment study was carried out by PIPIP Monitoring and Evaluation Consultants during 2018 for its evaluation, which reveals following impacts at the farm level
- Water Saving : 50 percent
- Crop yield enhancement : 20–100 percent
- Fertilizer use reduction : 40 percent
- Orchards maturing earlier : on-two years
- Early picking of vegetables : 10–15 days
- Value addition : Improved produce quality
- Increase in net farm income per acre per annum : PKR 75,000
- EIRR : 35.1 %