POPULARITY AND BENEFITS OF DRIP IRRIGATION

M.R. CHAUDHRY
Dec 17 - 30, 2007

In many countries of the Mediterranean especially those which fall in the arid climate zone with high rates of population growth, urbanization and industrialization water has become a scarce resource. Water availability for agriculture has thus become a big issue for these countries.

In the Mediterranean area, irrigation accounts for 72 percent of the total water withdrawals. In the southern Mediterranean countries, nearly 90 percent of the available water resources are allocated for irrigation. The limited water and high population growth is a major constraint for further agricultural and social economic development. Most of the developing countries are depending on agriculture for their economic as well industrial development as is the case of Pakistan where more than 70 percent of the industrial sector depends upon agricultural products as raw material to run the industrial units like textile mills, ghee/oil mills, flour mills and ginning factories.

The primary constraints for achieving food security are the low yield per unit area, increasing population and negligible scope for increasing the area of land for cultivation. In such a situation, the available option is intensification and diversification from the use of modern technologies, especially in seeds, fertilizers, irrigation, maximization of agricultural production, post harvest processing, storage, marketing and development of new technologies by research.

Some time ago water was considered as the free gift in most of the countries of the world. It has become a scarce commodity now and is a major threat for food production and food security. Different strategies were evolved and tried to ensure productive use of water, with optimum yield, constructing reservoirs for harvesting excess water especially in monsoonal regions and conserving water by better irrigation management practices such as drip irrigation.

Agriculture sector in Pakistan continues to be the single largest sector, which is the mainstay of 66 percent of the population of 162.5 million people. It accounts for 20.9 percent of the GDP and employs 43.4 percent of Pakistan's total workforce.

Drip irrigation: In revamping irrigation system, drip irrigation has been found to be the most effective technology. The principle of drip or micro irrigation is to deliver water to the root zone as the crop needs. This system is no less valid for fertilizers. The combination of irrigation water with fertilizer, known as "fertigation" is the obvious solution to get maximum benefits. Micro-irrigation is, therefore, meant to increase water use efficiency and its adoption is increasing.

In Israel these technologies have been tried, tested and perfected. There the micro irrigation area has increased from 10,000 hectares in 1975 to 104,000 hectares in 1999. It has far excelled by now. According to the estimate of FAO about 30,000 hectares in the Near East Region or 1.4 percent of the total area is under drip irrigation. In the Asia Pacific region this method is gaining popularity. In Sri Lanka many crops like banana, vegetables, flori-culture and other crops including coconut etc. are drip irrigated. Among the advantages, all nutrients are applied in soluble form and are readily available to the roots of the plants, thus increasing water and fertilizers use efficiency and reducing the labour cost. There is significant scope for increasing food production through this technology.

Drip irrigation is the most efficient method of irrigation. While efficiency of sprinkler system is around 75-85 percent, efficiency of drip irrigation system is 90 percent or higher. In drip irrigation much less water is wasted in irrigation.

In the backdrop of growing shortage of water for irrigation, drip irrigation is an efficient technique to improve irrigation efficiency, saving water and protecting the land from becoming saline and water-logged as against flood irrigation, which has otherwise been causing salinity and water-logging. This system has great importance in arid and semi-arid regions of the country such as Balochistan, Cholistan and Thal in Punjab and Thar areas of Sindh.

The government has already launched Rs.75 billion subsidized drip irrigation program for the next five years with a determination to improve irrigation efficiency. Reportedly drip irrigation at Nuclear Institute for Agriculture and Biology (NIAB) has proven quite successful and impressive. It provides a useful demonstration site for the education of extension workers, farmers and policy makers. A scientist at NIAB claims:

"We installed a model drip irrigation system that was used to irrigate cotton and the experiment was highly successful. The cotton yield with drip irrigation ranged from 1,520 to 1,680 kilograms per acre as compared to 960 kilograms per acre by using traditional flood irrigation method". He said that the government was so enthralled and enthused by the results that it has asked NIAB to develop a project proposal to spread this irrigation system in all the four provinces of Pakistan, covering a total area of 1,000 acres. In Faisalabad district, the scientists were able to grow cotton on an area of 7 acres with extraordinary yields by using as little water as possible. He hoped that the proposal prepared and submitted before the Planning Commission of Pakistan will be approved by the Commission.

Irrigation and agriculture experts are of the considered opinion that drip irrigation is most suitable in Pakistan with scarcity of water, low crop yield as compared to other neighboring countries and irrigation water wastage being high. Under the Subsidized Drip Irrigation Program, the traditional flood irrigation, which is wasteful and harmful to the soil in the long run, will be replaced by this innovative and effective method. Ehsan Qazi, an agricultural scientist at Lahore, regarding drip irrigation system is of the view: "Water directly reaches the roots, where it is actually needed. There is little wastage of water due to evaporation or seepage as usually happens in the case our traditional flood irrigation system". According to him, water saving can be as high as 70 percent.

Pakistan has also sought for the help of Japanese government to double the efficiency in irrigation water use, with the help of drip irrigation technology to the extent of 90 percent. The government's endeavor is to ensure that at least 300,000 acres of land will be brought under drip irrigation this year for which federal and provincial governments would be providing 80 percent subsidy on drip irrigation equipment.

Farmers should be encouraged, motivated and trained for the adoption of efficient water use technology such as sprinkler and drip irrigation. The experience of Israel, India and Iran are available for us to follow.