WASAMED Second International Workshop Thematic Network ¨ IRRIGATION SYSTEMS PERFORMANCE ¨ Tunisia, 25 - 28 June 2004 Country Report Cyprus I. Papadopoulos, C. Metochis and Dora ChimonidouAgricultural Research Institute, Nicosia, CY
In Cyprus, WATER is the mostimportant resource and a prerequisite for progress Its scarcity has acted as a limiting constraint for the development of agriculture and for other economic activities such as tourism
Eastern Mediterranean is characterized by low rainfall, concentrated during the winter months, and a long, warm and practically rainless period
Origin of water 57% of irrigation water is provided from Government Irrigation Schemes. The sources are, surface water, groundwater and reclaimed water. Irrigation outside Government Projects is satisfied by groundwater. Surface Water: Although the capacity of all the main dams is 274 MCM, the average annual amount of water available for use is about 102 MCM (during the dry year of 2000 the contribution to irrigation of all dams was only 28 MCM). Of the 102 MCM, 82 are used for irrigation within Government Projects, 15 for domestic use and 5 for ecological areas.
Groundwater extraction is about 127 MCM per year. Such figure does not mean the safe yield of the aquifers, which is much lower. Of this amount, 100 MCM are used for agriculture (26 MCM within the Government Irrigation Schemes and 74 MCM outside Government Projects). Springs contribute very little, amounting to 3.5 MCM per year, for domestic use of the mountainous villages. Desalination units at present contribute up to 33 MCM per year. Treated sewage effluent: Presently, about 3 MCM is used, of which 2 MCM for agriculture and the rest for landscape irrigation.
Measures • To overcome water scarcity, • measures had to be taken • in order toincrease the • available quantities of water • and to improve irrigation • management. • Emphasis was given on dam construction. The total water storage capacity increased from 6 million m3 in 1960 to about 300 million, corresponding to 50% of the mean annual rivers flow. • Concerning the improvement of irrigation management, the main effort was to introduce modern methods of water application, in order to increase water use efficiency.
Main advantages of modern irrigation systems • Significant water saving due to high irrigation efficiency. • Increased yields as a result of proper management. • Using drippers or minisprinklers, enables any other operation to be practiced even during water applications. • Utilization of soils with steeper slopes, unsuitable for irrigation with the conventional irrigation methods. • Poor quality (saline) water can be used due to frequent water application. • Limited labour is required due to automation (automatic metering valves, time switches, computers, etc).
Problems and drawbacks • Relatively high installation investment, ranging between 2200 and 7000 US$/ha. • Toxicity problems associated mainly with high sodium or chloride concentration in the irrigation water. In such cases low angle minisprinklers or, preferably, the drip irrigation system must be used. • Emitter clogging by suspended matter, chemical precipitates and biological slimes, particularly with drip irrigation. Various filters are installed (for impurities), water pH is adjusted to 6-7 by injection of acid (to avoid chemical precipitation) and chlorine is added into the system (to control biological growth).
Modern irrigation systems have been used in Cyprus agriculture for the last 30 years. Due to the relatively high installation cost, the drip method was initially used for irrigation of high value crops, such as greenhouse vegetables and flowers. At a later stage installation cost was reduced, and the use of drippers, minisprinklers and low capacity sprinklers was expanded for irrigating trees and field vegetables.
Proper hydraulic design of irrigation systems, offered free of charge by the Ministry, coupled by a subsidy of the installation cost, resulted in a rapid expansion of the new irrigation systems. The farmers have extensively adopted modern irrigation systems. It is estimated that currently over 95% of the total irrigated land of the country is being served by modern irrigation methods.
Selection of irrigation method The new technology introduced is continuously tested in order to evaluate the different systems under local conditions and select the appropriate irrigation method for each cultivation. • For densely spaced field vegetables (potatoes, carrots, beans, etc) the permanent low capacity sprinkler system is recommended for irrigation. In case, however, of limited financial resources the portable sprinkler system can be used instead, although it requires more labour. • Drip irrigation is the only applicable method for irrigation of row vegetables (greenhouses, low-tunnels and in the open field), spaced at a relatively great distance on the row and between rows.
For irrigation of permanent tree plantations both drippers and minisprinklers can be successfully used. Among permanent plantations, drippers are mainly recommended for banana, grapes and several other crops, like aromatic plants. With the improved irrigation systems and proper scheduling of irrigation, based on experimental work of the Agricultural Research Institute, the overall water use efficiency at farmers level increased to above 80%. The introduction of modern • irrigation systems resulted • in the increase of production • and improvement of yield • quality.
New trends Concerning greenhouses, particular attention is given to hydroponic culture on artificial substrates. Chemigation and fertigation are also other developments of major importance. The microclimatic conditions in the greenhouse are controlled in order to prevent fungal diseases of vegetables. The most significant trend has been towards greater control and automation, using programmable computer-based systems.
Advantages of using the • new greenhouse technology • Growth of crops can be easily controlled. • Avoiding soil born diseases and better root aeration. • Avoiding cultural practices (i.e. weed control). • Less energy requirement for warming up the root system. • Improving labour working conditions. • Use of areas where soils are not suitable for cultivation. • Saving of water and fertilizers from deep percolation. • Higher water use efficiency, increased yields and quality improvement.
CONCLUSIONS Water is by far the most precious resource in Cyprus. The quality of life and almost all economic activities depend upon the presence of an economic water supply. The present water situation is not sustainable, in spite of the impressive progress made in the last four decades. Much has been done but still a lot remains in the realm of water resources development and management. The continuous target is to ensure sustainability of the water sector of the island.
AGRICULTURAL RESEARCH INSTITUTE-CYPRUS