|Author:||Moutonnet, P. ; Heng, L. K.|
|Book Group Author:||NA|
Water is a scarce resource in Mediterranean countries. The optimal water requirement per capita is estimated to be around 1,700 m3/year; however, in many countries in West Asia, the available water is less than 500 m3/capita/year. The situation will deteriorate further during the next two decades as populations increase. Agriculture is the biggest consumer. About 80% of the renewable water resources are used for irrigation. Traditional methods such as furrow and surface irrigation are highly inefficient: only a third of the applied water is transpired by the crop. Clearly, there is great need to improve irrigation management. Recognizing the potential usefulness of nuclear techniques in fertigation studies, the IAEA implemented a Regional Technical-Cooperation Project from 1995 to 1998 with scientists in eight participating countries: Cyprus, Iran, Jordan, Lebanon, Saudi Arabia, Syria, Turkey, and the United Arab Emirates. The main objective was to examine water balance and fertigation practices, using nuclear techniques - soil moisture neutron probe and 15N-labelled fertilizers - with a view to improving crop production in arid and semi-arid zones. The objectives were to compare conventional fertilization methods with N-fertigation, by (1) evaluating the recovery of fertilizer N applied, (2) evaluating water use efficiency and estimating crop water requirements, and (3) evaluating potential nitrate pollution. To achieve these objectives, field experiments were included the following treatments: (1) Ns=N applied to the soil surface by furrow irrigation at the locally recommended rate, (2) N0=control, no N application, with drip irrigation, (3) N1=N applied by fertigation at 50% of the locally recommended rate, (4) N2=N applied by means of fertigation at 100% of the locally recommended rate, and (5) N3=N applied by means of fertigation at 150% of the locally recommended rate. At least four sets of data were collected for each of the countries involved. Crops included: tomato, pepper, potato, cotton, lettuce, garlic, and cucumber. Results clearly showed the superior efficiency of fertigation in terms of water use, fertilizer-N recovery, and crop yields. Summarized data show that fertigation is an efficient technique for conserving water and fertilizer N, and for increasing crop production. On average: (1) 42% of irrigation water was saved under drip irrigation, (2) there was a 42% increase in yield for fertigation compared with traditional fertilizer and water-management practices, (3) there was a 79% increase in efficiency of use of irrigation water based on crop yield.
arid zones, cotton, crop yield, cucumbers, fertigation,furrow irrigation, garlic, groundwater pollution, irrigation, irrigationwater, leaching, lettuces, moisture meters, neutron scattering, nitrate,nitrogen fertilizers, plant nutrition, plant water relations, pollutedwater, potatoes, semiarid zones, soil water content, techniques,tomatoes, trickle irrigation, use efficiency, water balance, waterconservation, water management, water quality, water requirements, wateruse efficiency, Cyprus, Iran, Jordan, Lebanon, Saudi Arabia, Syria,Turkey, United Arab Emirates, Allium sativum, Capsicum, Cucumis sativus,Gossypium, Lactuca sativa, Lycopersicon esculentum, Solanum tuberosum,Allium, Alliaceae, Liliaceae, Liliales, monocotyledons, angiosperms,Spermatophyta, plants, eukaryotes, Solanaceae, Solanales, dicotyledons,Cucumis, Cucurbitaceae, Violales, Malvaceae, Malvales, Lactuca,Asteraceae, Asterales, Lycopersicon, Solanum, West Asia, Asia,Mediterranean Region, Middle East, Develo