Showing 6 results for Irrigation System
Sayed Farhad Mousavi, Behrouz Mostafazadeh, Shokrollah Absalan,
Volume 2, Issue 4 (1-1999)
Abstract
This study aims to evaluate the present management of border irrigation systems applied to wheat, alfalfa and sugar-beet farms in Boyer-Ahmad and Gachsaran cities in Kohgiloyeh and Boyer-Ahmad Province. Experimental farms included 8 alfalfa farms, 5 wheat farms and 5 sugar-beet farms. The experiments were conducted at different growth stages of plants and customary borders with prevalent dimensions, slopes, and management practices. The relationship between management allowable deficit, moisture deficit before irrigation, and infiltrated depth indicated that in most cases either “deficit irrigation” or “stress irrigation” had been applied. This type of irrigation has positive effects on water use but negative effects on supply of required soil moisture for plants. In the first to third irrigations, measured application efficiencies ranged from 40.8% to 100%, 52.2% to 100%, and 61.1% to 100%, respectively. Graphs of advance, recession, and ideal recession showed the effects of border slope and length on inflow cut time and uniformity of water distribution. Water infiltration curves showed the amount of deficit irrigation. The results showed that weak irrigation management is the result of three parameters: lack of knowledge on the part of farmers about soil moisture conditions and correct time for irrigation, weak irrigation scheduling, as well as an imbalance between available water supply and irrigation requirements which leads to wasting water and reduced irrigation efficiency.
J. Abedi Koupai, A. Bakhtiarifar,
Volume 8, Issue 3 (10-2004)
Abstract
Water crisis is an important issue in arid and semi-arid regions like Iran. The situation has been getting more worse over recent years drought. Hence, there is a growing need to utilize low quality water where freshwater is scarce. In this regard, urban wastewater is a promising source but there are concerns about the environmental and health aspects of using such water. The main problem regarding the performance of trickle irrigation system utilizing wastewater effluents is clogging of the emitters. In this study, field trials at pilot scale were carried out to investigate the hydraulic properties of emitters using two types of water including treated wastewater and groundwater. The trickle irrigation system consisted of three 16 mm lateral tubes placed at 300 mm spacing in the main tube and each lateral tube had 16 emitters at 300-mm spacing. The designed discharge of the emitters was 4 L/h. The hydraulic properties of the different commercial emitters (micro flapper, long path, turbo plus and Eurokey) were assessed at different time periods.
The results indicated that the Eurokey and long path emitters had the maximum and minimum emission uniformity, respectively, when applying wastewater. using groundwater, the Eurokey and turbo plus emitters had the maximum and minimum emission uniformity, respectively, during the initial phase of the study. However, the Eurokey and long path emitters had the maximum and minimum uniformity values, respectively, at the end of the study. The turbo plus emitters are regulated and, as a result, showed no evidence of sensitivity to pressure variations hence, they can be used on uneven lands and where the trickle irrigation system has long lateral tubes.
M.rafiy Darani, M. Bakhshoodeh, M. Zibaee,
Volume 11, Issue 40 (7-2007)
Abstract
The main objective of this study was determining the best sprinkler system and ranking total operational sprinkler systems in Isfahan province. The data was collected through 262 questionnaires completed by farmers in Feridan and Semirom cities in Isfahan province. Ranking and comparing the systems were done via criteria matrix and qualitative efficiency of objects and compromise programming. Based on the results of this study, hand-move sprinkler irrigation and then solid-set sprinkler irrigation were found to be the best systems in most of the regions. However, solid-set sprinkler irrigation was the best in some other areas. Results also showed that there were trivial differences between farmer selection in sprinkler irrigation and suitable system in the region. Also, comparison of suitable system and conventional irrigations used by farmers showed that the current systems of farmers are not usually an optimal system.
F. Fathi, M. Zibaei ,
Volume 14, Issue 53 (10-2010)
Abstract
Overexploitation of groundwater resource may result in lowering groundwater table at a faster rate due to an imbalance in the total recharge and total withdrawal. In order to make a balance between groundwater exploitation and recharge, the major remedial measures suggested are to strengthen groundwater management, adopt water demand policies, raise water use efficiency, and to increase water supply. Because there is a trade off between farmers’ income and sustainability of groundwater based farming, it is essential that a mathematical model be used to study the effects of withdrawal on farmers' income and sustainability of farm. Such a model can determine optimal crop pattern, suitable irrigation strategies and irrigation methods at different levels of available irrigation water. The relationship between farmers’ income and the withdrawal was then examined using multi-objective programming. The data were obtained from a systematic random sampling method through which 112 farmers were chosen. The percentage decrease in the profit was less than that of the withdrawal for all representative farmers, based on the results obtained from multi-objective method. For example, 8% reduction of groundwater pumping could be imposed without a serious impact on the farmers' income (farmers' income falls about 4%). Finally, the results of this study can help farmers to choose crop patterns, irrigation strategies and irrigation methods in such a way that both farmers’ income and withdrawal are simultaneously optimized and lead to a decrease in extracting groundwater compared to the current status.
H. Naghavi, M. Hosseini Nia, Sh. Karimi Googhari, M. Irandost,
Volume 16, Issue 61 (10-2012)
Abstract
Knowing about the way water is distributed in the soil is essential for designing and managing the Subsurface Drip Irrigation systems (SDI). Since carrying out experiments to recognize the form of moisture distribution in the soil is too complicated and time-consuming, using numerical simulations can be an efficient, effective substitute method to design these systems. One of these models is HYDRUS-2D, which is able to simulate the movement of water, heat and solute in saturated and unsaturated conditions in soil. This research aims to figure out the extent to which the HYDRUS-2D model is able to estimate wetting pattern in soil around a dripper. The simulations’ findings were compared to the data gathered from the field, including SDI system in different irrigation times, and 72 hours after irrigation. Moreover, the rates of error were measured for all points and distances from the dripper in all times of irrigation and also beyond that. The results indicated that the model can simulate the changes, trend similar to what happened in the soil profile. However, it estimated the rate of soil moisture with higher errors in those points in which the wetting took place, with the maximum error rate being RMSE= 0.05 per every 1.5 hours after irrigation starting point in the depth of 30 centimeters where dripper is placed. Also, with an increase in the irrigation time, and soil moisture evening which resulted from redistribution of moisture, the model resulted in better estimations. 72 hours after finishing the irrigation, the estimates were closer to real figures with an average error estimate of RMSE= 0.002.
Y. Gateazadeh, H.a. Kashkuli, D. Khodadadi Dehkordi, A. Mokhtaran, A. Assareh,
Volume 27, Issue 2 (9-2023)
Abstract
To monitor and compare the changes of salts in the soil profile around the roots of the corn plant, the plant yield, and the productivity of corn water, an Experimental was conducted in a completely randomized block of three repetitions in two crop years 2017-2018 and 2018-2019 at Ahvaz Agricultural Research Station. Experimental treatments included two subsurface drip irrigation systems with a working depth of 30 cm from the soil surface and tape irrigation and two irrigation intervals of 2 and 4 days. The results of monitoring soil solutes obtained from sampling depths (0-25, 25-50, and 75-50 cm) showed that soil salinity in the second year in both systems as a result of improving the quality of irrigation water from 3.61 dS/m to 2.01 dS/m, it was reduced by two times. The results of soil salinity monitoring showed the highest ratio of salinity reduction with a 2-day irrigation interval in both irrigation systems. The most leaching was done at the irrigation depth of 25-50 cm in the subsurface drip irrigation system and at the depth of 0-25 cm in the tape system. The highest yield of corn dry fodder was 9.13 and 7.13 tons per hectare, respectively, and the best water efficiency based on dry corn fodder at the rate of 13.74 kg/m was obtained in the strip drip irrigation system (tape) with a two-day irrigation interval and in the second crop year. Also, the results of the soil salinity measurement showed that the implementation and exploitation of the drip irrigation system can be the basis for improving the quality of the soil as the most important non-renewable resource of agriculture.
