ارزیابی عملکرد سیستم آبیاری بارانی عقربه ای در کرج

Irrigation systems may or may not be well designed and properly used. Therefore, it is necessary to study these systems to provide direction to management in deciding whether to continue existing practices or to improve upon them. The major objective of this study is to determine the evaluation factors of center-pivot irrigation system and factors which usually affect irrigation performance. A solution. for the improvement of irrigation water use will be presented and design and management problems, will also be mentioned. To achieve the objectives of this study, the characteristics of the soil and the growing plant (seed corn) along with design parameters were determined. The system was designed on the basis of soil and the growing plant characteristics in the 500-ha farm of Ministry of Agriculture (located in the North East of Meshkinabad, Karaj) having a silty loam texture. Then, it was examined with respect to the existing conditions. Four radial rows of catch containers spacing 6 meters were set up and then field data for performance evaluation of system were determined. The evaluation factors were calculated on the basis of field data analysis. The results obtained are as follows: During the growing season, the average PELQ, AELQ and DU for the center-pivot system were about 79, 75.8 and 84 percent, respectively. Analysis of evaluation factors indicated that the system is not efficient DU and PELQ values were not high enough for the system because it was not properly designed for the existing conditions. Al the same time, it seems that the difference between PELQ and AELQ values are meaningful which may indicate management difficulties.