Showing 17 results for Drip Irrigation
Behrouz Mostafazadeh, Sayed-Farhad Mousavi, Mohammad Hossain Sharif-Bayanolhagh,
Volume 2, Issue 3 (10-1998)
Abstract
To determine the effects of field slope, emitter discharge, irrigation water volume and soil texture on soil moisture profile and soil surface wetted shape from a point source, field data were collected on three different soil types, three emitter discharges (4, 8, and 12 lph), four slopes (0, 2, 5, and 10%), and five irrigation water volumes (10, 20, 30, 40, and 50 liters) with three replications. The results showed that the surface-wetted area increases as the emitter discharge increases. The surface-wetted area decreased with a corresponding increase in emitter discharge in experimental fields with light-textured soils. In experimental fields with heavy textured soils and slopes greater than 5%, the changes in surface-wetted area due to the emitter discharge increases, were higher compared to slopes of less than 5%. Since, a higher emitter discharge would result in higher surface-wetted area, the results showed that for an equal volume of irrigation water, the soil moisture profile was deeper for lower emitter discharge. In general, the volume of wetted zone was higher for greater emitter discharges. It was found that as the volume of irrigation water increased, the volume of wetted zone would increase correspondingly. This effect is more prominent than that of emitter discharge. In general, the depth of wetting front was lower and the wetted surface area was greater for heavy textured soils as compared to the light textured soils. The wetted-surface area and the shape of wetting front in the direction of slope were affected by the soil infiltration, emitter discharge and volume of irrigation water where these effects were more critical in higher sloping lands.
A. Hassanli, A. Sepaskhah,
Volume 4, Issue 2 (7-2000)
Abstract
In this study, seven citrus gardens in different parts of Darab were chosen to evaluate the drip irrigation systems. The evaluation process was based on the Merriam and Keller’s model (1978). Besides the evaluation of drip irrigation systems, the water requirement of citrus was estimated using four models including Blany-Criddle modified by FAO, Hargrive-Samani, Pan Evaporation and Solomon-Kodama model. On the basis of the results obtained by Hargrive-Samani with 1296 mm annual water requirements, a comparison was made between irrigation with existing systems and irrigation under favorable and desired conditions.
The results from field measurements indicate a considerable reduction in the emitter discharges. The low pressure and emitter clogging could be two major reasons for the problem. Low pressure at head control, topography, head losses and also using no filter(s) or unefficient filters are the main reasons for the reduction. In some gardens, overirrigation even up to 2.5 times of water requirement was practiced by using extra emitters and increased irrigation times. Overirrigation causes considerable water losses through deep percolation and in reased overwetting area.
Field measurements indicated a good emission uniformity (EU) for the fields with overirrigation. EU in chosen fields varied from 40 to 91%, AELQ varied from 31 to 82% (poor to good) and PELQ varied from 36 to 82%. This study showed that most farmers are not familiar with plant water requirements. The fields with efficient filtration due to using extra emitters per plant are mainly overirrigated. But fields without any filter of unefficient filters are not irrigated sufficiently. The very high manufacturing variation coefficient of IEM emitters (Cv=0.22), which are widely used in Darab, causes a design emission uniformity of 55%.
A. Alizadeh, A.g. Ghorbani, G.h. Haghnia,
Volume 4, Issue 4 (1-2001)
Abstract
In order to compare the effect of drip and furrow irrigation methods with different quantities of water (50%, 75%, and 100% of the amount of water evaporated from class A pan evaporation during irrigation intervals) on yield and quality of tomato, an experiment was conducted on a silty loam soil in Mashhad Agricultural Research Station. The experimental design was a factorial trial with completely randomized blocks and. four replications.
The results showed that the highest yield (51 t/ha) was obtained from the treatment of drip irrigation with 100% water application. This amount was 4.5 tons higher than the yield from furrow irrigation treatment. Deficit irrigation by 25 and 50 percent decreased total yield by 34.7% and 67.95% in the drip irrigation method and by 27.57% and 64.29% in the furrow irrigation, respectively. Water use efficiency in drip irrigation was two times higher than that in the furrow treatment. Quality and chemical composition of the fruits were not significantly different in the two irrigation methods. Increasing the water deficit, however, increased the amount of soluble solids of the fruits.
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.
P. Shahinrokhsar, M. E Asadi,
Volume 16, Issue 61 (10-2012)
Abstract
Modification of irrigation scheduling and management improvement of irrigation systems are two essential factors that have significant impact on agricultural water use efficiency. Therefore, a field experiment was conducted to evaluate the effect of tape drip irrigation (T) and furrow irrigation systems (S) under different irrigation regimes on yield and yield components of soybean in growing season of 2006-2007 at Gorgan Agricultural Research Station in north part of Iran. The experiment was laid out in a split plot design in a randomized complete form where each treatment was replicated three times. The main plots were irrigation systems of tape and furrow, and three irrigation regimes 100 (I100) , 75 (I75) and 50 (I50) percent of total irrigation requirement were chosen as secondary plots. Results showed that thousandgrain weight (gr) and plant height (cm) in furrow irrigation were significantly more than the tape drip irrigation method. Also significant differences between different irrigation regimes in terms of plant height, node numbers and yield were observed. So, I100 and I50 had highest and lowest values, respectively. In terms of irrigation system, 63 percent of water consumption was reduced in tape drip irrigation method. Also, the results indicated that higher and lower water use efficiencies were obtained from tape drip irrigation method with I50 treatment (1.09 kg m-3) and furrow irrigation with I100 treatment (0.50 kg m3), respectively.
R. Asadi, F. Hassanpor, M. Tabatabaei, N. Koohi,
Volume 17, Issue 63 (6-2013)
Abstract
Application of the modern irrigation systems such as T-Tape irrigation system is one of the ways to achieve aptimal irrigation The present study deals with the effect of surface and subsurface drip irrigation systems on the cotton yield For this purpose, a field experiment was conducted in the Agricultural and Natural Resource Research Institute of Orzoueyeh, located in the Kerman province. The experiments were conducted in a split plot design based on the Randomized Complete Block Design (RCBD) with three replications. The treatments were comprised of three levels of the crop water requirements (i.e. irrigation based on 100, 80 and 60 percent of crop water requirement) in main plot and with the two irrigation systems, surface one and subsurface one. The results showed that the yield resulting from treatments with 60 and 80 percent crop water requirement was respectively 981 and 413 kg/ha lower than that of treatment with 100 percent crop water requirement. In addition, the obtained yield due to subsurface system was 248 kg/ha greater than that of the surface pattern. The interaction of treatments on the yield of the crop also indicates that the treatment with subsurface system and 100 percent crop water requirement produces the maximum yield. Despite equal water consumption in each sub plots, the WUE in subsurface system was 14 percent higher than that of surface system. From the economical point of view, benefit to cost ratio in the subsurface system is 8 percent less than surface system. Considering the results obtained in this study in the light of water saving as the main objective in deficit irrigation and water use efficiency (WUE) for cotton cultivation in Orzoueyeh, the 80% of crop water requirement is preferred
A. Ahmadnejad, J. Abedi Koupai, F. Mousavi,
Volume 17, Issue 66 (2-2014)
Abstract
Sesame (Sesamum indicum L.) is one of the most important oilseed crops in the world. Drought stress is one of the environmental factors limiting sesame production. The effects of water deficiency can be reduced by inoculation of plant roots with mycorrhiza fungi. In this experiment, the objective was to determine the effects of different levels of water application (60, 80 and 100% of soil moisture depletion) using surface drip irrigation method and inoculation of plants with mycorrhiza on WUEag of sesame. The experiment was arranged using a factorial design based on randomized complete block design with three replications. The field experiment was conducted at the Agricultural Research Farm of Isfahan University of Technology in 2011. Results showed that the effect of irrigation regime on WUEag of seed yield was not significant. However, the effect of mycorrhiza on WUEag of seed yield was significant. The highest WUEag (0.74 kg/m3) was related to irrigation regime of 80% and mycorrhiza. The effect of irrigation regime and mycorrhiza on WUEag of oil yield were significant. The highest WUEag (0.43 kg/m3) was related to irrigation regime of 100% and mycorrhiza inoculation.
H. Shekofteh,
Volume 18, Issue 69 (12-2014)
Abstract
In order to study the effect of depth of drip placement in soil in subsurface drip irrigation, and fertilization time during irrigation events, on tuber yield of potato, an experiment was carried out in Jiroft area in 1389. This experiment was in a completely randomized block design with four replications, with depth placement of drip tape as the main plot, and fertilization time as the sub-plot. Results showed that depth placement of drip tape had a significant effect on tuber yield, plant height, number of stems, stem diameter and dry plant weight at 1% level, number of tubers in plant, and wet plant weight and stolen height at 5% level. Fertilization time had a significant effect on tuber yield, stem diameter, stem number in plant, and plant height at 1% level and on dry plant weight and plant tuber number at 5% level. But, it did not show any significant effect on other attributes. Also, interactional effects of treatments were significant on tuber yield per plant, stem diameter, plant height, and number of tubers at 1% level, and on dry plant weight at 5% level, but the effect on other traits was not significant. According to the statistical results, the highest yield was obtained from the depth of 15 cm and middle time of fertilization.
R. Ramzi, A. Khashei-Siuki, A. Shahidi,
Volume 18, Issue 69 (12-2014)
Abstract
Limitation of available water resources and crisis of water scarcity has been discussed in water conferences since a long time ago. In Iran’s climatic conditions, the most important problem for increasing agricultural production is limitation of available water resources. Drip irrigation methods are one of the suitable solutions for efficient use of water resources under a condition that selection, design, implementation and operation of drip irrigation systems would perform precisely. In this study, potential and suitability of drip irrigation systems in South Khorasan province was analyzed according to climatic conditions, quality of groundwater resources, topographical status and soil profile areas. To do this, all the effective parameters in drip irrigation are zonated and classified using software Arc GIS 9.3 and then using computational average method in AHP they are turned into a map to find suitable places for drip irrigation in the province. According to the study, about 50 percent of the land in South Khorasan province has the ability to use the drip irrigation system. The remaining 50 percent can also be used for drip systems if improved, with the exception of 9 plains. However, the performed drip irrigation plans are rare in this province and there should be more efforts to inform farmers to develop such systems in this province.
S. M. Mousavi, S. M. Mirlatifi, S. H. Tabatabaei,
Volume 19, Issue 71 (6-2015)
Abstract
The effects of water quality, installation depth and space of subsurface drip irrigation (SDI) laterals on yield and visual quality of turfgrass were investigated. A field experiment was conducted at the experimental farm of Shahrekord University. The experimental design was a Split-Split Plot with experimental arrangement of completely randomized block design with 16 treatments and three replications. Treatments included two types of water quality: well water (W) and treated wastewater (WW), two installation spaces of SDI laterals (45 and 60 cm) and four depths of placement of SDI laterals (15, 20, 25 and 30 cm). Turfgrass indices recorded during the experiment included height, dry mass, color, visual density and growth uniformity. The ANOVA results showed that interaction of irrigation water quality × lateral spacing × installation depth of SDI laterals is significant on the height, dry mass and growth uniformity of turfgrass. Irrigation with wastewater as compared to well water produced grass with significantly higher height and more dry weight. Treatments irrigated with well water had a better growth uniformity than those treatments irrigated with wastewater. Results indicated that there was no significant effect of experimental factors on turfgrass color. The interactional effect of lateral spacing and installation depth on the turfgrass density was significant. Increasing installation depth and laterals spacing caused a decrease in turf’s yield and visual quality.
N. Khanmohamadi, S. Besharat,
Volume 20, Issue 77 (11-2016)
Abstract
Accurate design of drip irrigation systems requires sufficient understanding of horizontally and vertically distribution of water flow in soil and modeling the wetting pattern dimensions created under the drip source. Field and laboratory activities are not suitable for this purpose considering their time and financial constraints and it is necessary to apply accurate software for determination of several equations in different situations. This research aimed to present simple models for calculation of wetting pattern dimensions in different discharges and structures in drip irrigation system. For this purpose, HYDRUS-2D model was implemented for four discharges in the same soil texture and different soil textures in the same discharge. The values obtained from running the software such as depth and maximum diameter of wetting pattern have been fitted with time values and corresponding equations were obtained. The results of statistical indices for all obtained equations (R>0.96, RMSE<2.12 and MAD<1.38) represent suitable accuracy of corresponding equations in determination of pattern dimensions under the drip source. The results also showed that Loamy Sand and Silt textures, respectively, have maximum and minimum depth and wetting pattern diameter.
C. Abdi, P. Fathi,
Volume 21, Issue 3 (11-2017)
Abstract
Drip irrigation is one of the new irrigation methods for optimum use of water resources and increase of irrigation efficiency. The emitters' clogging is the most important problem in these systems. The physical clogging is the most important factor in reducing the discharge and emission uniformity of emitters. The emitter position on the laterals and emitter spacing are the factors that affect the physical clogging rate of emitters. The objective of the present study is evaluating the effect of emitter spacing of drip irrigation tape on the physical clogging rate of emitters. For this purpose, a physical model of drip irrigation tape was designed and made at the laboratory. In this research, seamless and seamed irrigation tapes with emitter spacing equal to 10, 20 and 30 centimeters were used. Statistical analysis showed that emitters spacing have significant effect on clogging rate of emitters in seamless and seamed drip irrigation tapes. The results also indicated that seamless irrigation tapes with 30-centimeter emitters spacing, with clogging rate of 22 percent, have the least clogging. A comparison of clogging rate and uniformity coefficient of irrigation tape showed the higher performance of seamless irrigation tape in clogging condition.
M. Shahsavari Gugharغ, A. Rezaei Estakhroieh, M. Irandost, A. Neshat,
Volume 22, Issue 1 (6-2018)
Abstract
With the increase of population, the optimal use of water resources is necessary. This study was carried out to evaluate the impact of different levels of irrigation on the yield, yield components and water productivity of corn using single and double row drip irrigation systems (Tubes type). . The experiment was conducted in a split plot design based on the randomized complete block design (RCBD) with three replications in 2012 in Hajiabad, Hormozgan Province. The treatments were comprised of three levels of irrigation as the main plot (100, 80 and 60% water requirement) and two patterns of irrigating water pipe installation (normal and every other row) as a sub-plot of the design. The results showed that irrigating with the 80 percent water requirement, in comparison with full irrigation, increased the total yield by 1.4%, the seed weight by 1.8%, the number of seeds per row by 8.7%, and the number of seed row per maize by 13%. In spite of yield superiority in the pattern of normally irrigating water pipe installation (10055.56 kg ha-1), against every other row installation (9366.67 kg ha-1), water productivity was more in every other row installation (1.089 kg m-3). Therefore, partial root-zone drying was recommended by the irrigation of the 80% plant water requirement for the maize in the region.
Z. Heidari, M. Farasati, R. Ghobadian,
Volume 22, Issue 2 (9-2018)
Abstract
To design cost-effective and efficient drip irrigation systems, it is necessary to know the vertical and horizontal advance of the wetting front under the point source; also, the proper management of drip irrigation systems requires an awareness of the soil water distribution. Many factors influence wetting pattern dimensions, including discharge, land slope, irrigation time and soil texture. The purpose of this study was to investigate the applicability of the support vector machine in simulating the wetting pattern under trickle irrigation. After preparing a physical model made of Plexiglas with specific dimensions and filled with silty clay loam soils, experiments were conducted in the irrigation laboratory of Razi University, Iran, with emitters of 2, 4, 6 and 8 l/hour discharge during the irrigation intervals of 2 hours and 24 hours redistribution and 0,5,15 and 20% slope with three replications. In this study, the statistical indicators R2, RMSE, MBE and MEF were used. R2 values for the wet depth, width and area were 0.96, 0.96 and 0.92, respectively. Regarding the MBE value, the SVM model estimated the wet width and depth parameters to be 3% less than the actual value, and simulated the wet area 2.04% less than the real value. Also, according to the MEF and RMSE values, the SVM model simulated the wet area parameter with more error. Overall, the results showed that the SVM model had a high ability to estimate the wetting pattern parameters.
M. Khast, M. Hesam, A. Hezarjaribi, O. Mohamadi,
Volume 24, Issue 1 (5-2020)
Abstract
Due to the increasing number of small crops, the system of irrigation without a pump can be an economical way. Therefore, in this research, the effects of the type of droplet and the height of water supply system utilization on the characteristics of water distribution (discharge, dispersion uniformity coefficient (CU) and coefficients of variation of discharge) were investigated. In this research, the pressure functions of 1, 2, 3 and 4 meters and three irrigation repeats were investigated; also, the discharge characteristics of jet pots of 2 and 8 nozzles, easy dripper and netafim were addressed. The results indicated that at 1 m pressure, drippers of pots of 2 and 8 nozzles with the uniformity coefficients of distribution were equal to 89.39 and 99.30%, and the discharge rate was 3.60 and 3.62 liters per hour at a pressure of 2 m. An easy-drain drip with a discharge rate of 3.85 L / h and a uniform distribution of 99.44%, at a height of 3 and 4 m, the droplets of the netafim with an outlet discharge were 3.87 and 3.97 liters per hour and the uniformity coefficients of 99.32 and 99.47 percent had the best broadcast conditions. According to these significant differences (P <0.05), it can be concluded that at pressures less than 2 m of jar droplets and at more than 3 m, netafim and Easy Dipper types could have better leakage due to pressure regulators. In general, each of the four types of emitters produced a uniform dispersion and the optimum discharge at different pressures.
A. Yousefi, M. Maleki-Zadeh, A.r. Nikooie, M.s. Ebrahimi,
Volume 26, Issue 4 (3-2023)
Abstract
This study determines the amount of irrigation water saved as a result of the subsidy policy to adapt from flood to drip irrigation. We developed a positive mathematical programming model (PMP) to evaluate the effect of economic incentives on farmers’ decisions to choose the type of irrigation technology, cropping pattern, and "water use" and "water consumption" in rural Garkan Shomali district, which is part of the Najafabad aquifer. We collected data through farm surveys, desk research, and expert interviews. The results showed that a reduction in the financial costs of converting flood irrigation into drip irrigation can lead to farmers investing in this technology. In the current water allocation scenario, the subsidy policy increases the water consumption of drip-irrigated crops by 28%, of which 19% is non-consumed water before subsidy payment and the rest is related to the reduction of furrow-irrigated lands. Also, under non-volumetric water delivery conditions, the operating costs reduce and the net income of the farms increases because of the increase in efficiency and the development of the area under cultivation, which increases water consumption while the water use is constant. In the volumetric water delivery scenario, with the increase in subsidies, the net income of the farms will increase without developing the area under cultivation and only because of the increased yield. Therefore, subsidy policy increases irrigation efficiency at both the farm and regional levels and is an effective tool for dealing with drought conditions.
P. Papan, M. Albaji, R Kh. Peyghan,
Volume 27, Issue 1 (5-2023)
Abstract
Population growth and limited water and soil resources make it necessary to pay attention to the factors affecting food production, including the suitability of irrigation methods with agricultural lands. The objective of this study was to assess land suitability for surface, drip, and sprinkler irrigation methods based on a parametric evaluation system in an area of 250 hectares in the Shahid Rajaei plain of Khuzestan. Soil properties were analyzed, then suitability maps for different irrigation methods were prepared using a geographic information system (GIS). The results showed that for surface irrigation, 704 ha (31.3%) was marginally suitable (S3), 866 ha (38.5%) was currently not suitable (N1), and 680 ha (30.2%) was permanently not suitable (N2). For drip irrigation, 8 hectares (0.4%) are highly suitable (S1), 644 hectares (28.6%) are moderately suitable (S2), 52 hectares (2.3%) are marginally suitable (S3), 866 hectares (38.5%) were currently not suitable (N1), and 680 hectares (30.2%) were permanently not suitable (N2). For sprinkler irrigation, 652 hectares (29%) are moderately suitable (S2), 52 hectares (2.3%) are marginally suitable (S3), 866 hectares (38.5%) are currently not suitable (N1), and 680 hectares (30.2%) were permanently not suitable (N2). According to the results, sprinkler irrigation with an irrigation capability index of 29.9 to 60.7 in 2242 hectares (99.6%) is preferable to other irrigation methods. Drip irrigation in 8 hectares (0.4%) was found to be the most suitable method. The main limiting factors in using all three irrigation methods included salinity, alkalinity, and drainage. Also, soil calcium carbonate was added to the limiting factors in drip irrigation.
