A. M. Battikhi

Comparison between the efficiencies of surface and pressurized irrigation systems in Jordan

A study was carried out to determine the efficiencies of water use in irrigation in the Jordan Valley Project. The study aimed to evaluate, the overall or project efficiency (Ep) which includes: the irrigation system efficiency, being the combined conveyance and distribution efficiency (Es); and the field application efficiency (Ea). Evaluation of these efficiencies includes the comparison of open canals with surface irrigation versus pressurized pipes with sprinkler or drip irrigation systems. Data was collected from different sources to achieve the above mentioned purposes, beside the field experiments which were carried out specially for this study.It was found that the overall or project efficiency (Ep) for open surface canal with surface irrigation under citrus was 53%. While it was 42% under vegetables. Whereas Ep for pressurized pipe systems was 68%, and 70% for sprinkler and drip irrigation methods, respectively.The Es for an open canal, (King Abdullah Canal, KAC) was 65%. While it was 77% for pressurized pipe projects during 1989–1991. Concerning the Ea, it was found to be equal to 82% and 64%, for surface irrigation on citrus and vegetables, respectively. Whereas it was 88% for citrus under sprinkler, and 91% for vegetables under drip irrigation. These values for the field application efficiency are acceptable according to Finkle (1982). The low Es value for the canal is due, mainly, to high evaporation and seepage, unreported deliveries, and unavoidable measurement losses. Whereas, in pressurized pipe projects, it is due to the unreported deliveries, unavoidable measurement losses, and leakage.

Irrigation scheduling and cantaloupe yield model for the Jordan Valley

Abstract A crop yield and soil water management simulation model (CRPSM) developed at Utah State University was modified and calibrated using data from a trickle irrigation experiment with different mulched treatments on cantaloupe ( Cucumis melo L.) in the Jordan Valley. The soil water budget model was adapted to the field conditions through input describing rooting depth, field capacity, wilting point and wet soil surface air-drying characteristics. Observed field crop growth progress was used for the models phenology clock. Calibration of the yield model was accomplished by adjusting model parameters to obtain a reasonable match between model and field yields. Simulated possible irrigation schedules were tested using different options provided by the model. By using 1.5 cm per irrigation for a total of 44 to 47 irrigations and starting the first instead of the last of April, simulated yields were about double what was actually obtained in the field. This indicates that the date of first irrigation as well as total water applied is important for maximizing yield. Plants in the field were apparently subjected to water stress prior to late April when irrigation was initiated. The use of the CRPSM model could reduce the number of plots needed in further field experimentation since the less successful possibilities could be identified by simulation. Thus, field efforts can be concentrated on treatments most likely to provide higher yields with improved irrigation management.

Impacts of Treated Wastewater Reuse on Some Soil Properties and Production ofGladiolus communis

Two experiments, one in Open Field (OF) and the other inside a Greenhouse (GH), were conducted at Al-Jubeha Agricultural Research Station –The University of Jordan, to study the effect of Treated Wastewater (TWW) on soil chemical and physical properties. It was also intended to find the effect of TWW on spike quality of gladiolus. Five water treatments were used for both experiments, T1:100% Potable Water (PW); T2:100%TWW; T3:25%PW +75%TWW; T4:50%PW+50%TWW; and T5:75%PW+25%TWW. The design for both experiments was Randomized Complete Block Design (RCBD). The results in both experiments showed high accumulation of salts in soils for all treatments with the highest accumulation values in soil T2. Soil organic matter (OM) and N were reduced after planting for all treatments in the GH treatments, but OM remained almost the same in the OF treatments. There was an increase in Zn, Pb, and Cu microelements in soils for all treatments. Soil physical properties such as aggregate stability was reduced for all treatments significantly after planting by about 40% for the GH treatments, and nonsignificantly by about 3-12% for the OF treatments. Soil water retention curve and pore size distribution did not significantly change after planting for the soil for all treatments in both experiments. Plant properties, from both experiments, were affected by TWW irrigation. Parameters such as: spike length, spike diameter, corm size, number of florets per spike, and the number of cormels per corm were found to be affected by water treatments. It gave the worst quality for plants that irrigated with 100% TWW for both experiments. Based on results obtained from both experiments, it was found that soils were affected negatively by TWW irrigation for their chemical and physical properties. Use of TWW when mixed with some PW for irrigation of non-edible plants such as cut flowers gave better results than using PW alone.