Showing 72 results for Efficiency
H. Asadi, M. Aligoli, M. Gorji,
Volume 20, Issue 78 (1-2017)
Abstract
This study aimed to investigate the dynamic changes of rill erosion and evaluate the ability of Hairsine-Rose model in estimation of sediment concentration. The experiments were carried out at the Soil and Water Conservation Research Station of Tehran University in Kuhin, Qazvin. Four flow rates were tested at three slopes in trapezoidal hand-made rills of 3 m long and 5 cm base width. Outflows were sampled periodically to determine changes in sediment concentration. The experiments were repeated in early autumn and mid spring. Sediment concentration showed a dynamic change with time which was affected by flow rate, slope and season. The sediment concentration was high in the first few minutes of the experiment but over time, dropped and finally reached a more or less stable state. The effects of flow rate and slope were more detectable on sediment concentration at the early unsteady conditions than at the final steady conditions. Though the temporal trends were similar, the sediment concentration was generally higher in autumn than in spring. Hairsine-rose model showed a better performance at lower flow stream powers but generally over predicted sediment concentration showing a systematic error probably due to model formulation.
S. Vaseghi, M. Valinejad, M. Afyuni,
Volume 21, Issue 3 (11-2017)
Abstract
Nitrogen use efficiency is relatively low in irrigated rice fields because of rapid N losses from ammonia volatilization, the nitrification, surface runoff, and leaching in the soil-flood water system. Since the plant N represents the total N supply of all sources, plant N status will be a good indicator of N availability to crops at any given time. Leaf colour chart (LCC) is a simple portable diagnostic tool, to determine the timing of N top dressing. LCC was developed to increase the N use efficiency at irrigated rice fields. A field experiment was carried out to compare the effect of N split application and LCC on the grain yield and agronomic and recovery efficiency of Fajr variety in 2009. The experiment was conducted in a randomized complete block design with 12 treatments in 3 replications on Fajr cultivar. Twelve treatments included control treatments (without nitrogen fertilizer) and 45, 90, 135 kg N ha-1 for three times each and two treatments included LCC treatments 4 and 5. As a result, all treatments showed significant (p=0.05) grain yield increase in comparison to control. Increased yield was observed up to 135 kgN/ha (55.2%). Grain yield of LCC treatments was higher than split treatments. LCC treatment 5 had higher AE, RE, PE, PFP and IE than LCC 4 and fixed – 135 at the less N rate in all fields. Therefore, the results of different fertilizer treatments showed that the LCC treatment 5 with maximum grain yield, agronomic, physiological, internal and relative efficiency factors can be considered as the best management method for using nitrogen fertilizer and preventing from excess use of nitrogen fertilizer in Fajr cultivar.
A. R. Vaezi, M. Ahmadi,
Volume 21, Issue 3 (11-2017)
Abstract
Modified Universal Soil Loss Equation (MUSLE) is one of soil loss estimation models which has been developed based on the runoff characteristics in the event scale. However, it needs to be evaluated in the plot scale for the semi-arid rainfall events. With this aim, a field study was designed using twenty one plots. Runoff and soil loss were measured using 5-min samples under seven rainfall intensities consisted of 10, 20, 30, 40, 50 60, and 70 mm h-1 for 60 min. Soil loss was estimated using the MUSLE based on the runoff volume (Q) and runoff peak discharge (qp) and the values were compared with the observed values. The estimated soil loss was about 3.89 times bigger than the observed value on average. In order to improve model estimations, the power of rainfall erosivity index was modified from 0.56 to 0.62, (Q qp)0.62. The modification of the MUSLE model improved model efficiency (ME) from -5.5 to 0.47 and decreased the root mean square error from 0.000137 to 0.000031. This study revealed that the MUSLE overestimates soil loss from the small plots in the semi -arid regions. Therefore it is essential to calibrate runoff erosivity index using the data observed in the area. The modified MUSLE can be reliably used to predict soil loss in the small plot scale in semi-arid regions.
N. Nourmahnad,
Volume 22, Issue 2 (9-2018)
Abstract
Due to the water scarcity in Iran, it is important to provide strategies to reduce water consumption in the agriculture sector. Zycosil is a nanotechnology material that makes a great hydrophobe in the soil. This study was conducted based on completely randomized block design within microlysimeter with the height of 15 cm and the diameter of 8 cm to investigate the hydrophobic effect on the amount of consumed water in pepper. Sweet pepper seedlings were planted in them; then the treatments were applied. The Z25, Z50 and Z75 treatments consisted of covering 25, 50 and 75 % of the soil surface by Zycosil; these were compared with the control (Ctrl- no Zycosil application) in three replications. The results showed that Z75 treatment reduced 27% water consumption and increased the fresh yield by approximately 62 %. The increased yield of Z25 and Z50 was 5 and 26 %, respectively. Dry pepper yield was increased in Z25, Z50 and Z75 treatments by 22, 19 and 80%, respectively, as compared to Ctrl treatment. The amount of water consumed was decreased by 10 % per 25% coverage level. The least amount of water use efficiency was observed in the control treatment (1.28 gr/cm3). The Z75 had the highest water use efficiency (2.96 gr/cm3). Hence, the application of hydrophobic material such as Zycosil in the soil surface reduced water evaporation and increased water retention. This increased the yield and water use efficiency.
F. Sajadi, H. Sharifan, S. Jamali,
Volume 22, Issue 3 (11-2018)
Abstract
Yield is a function of root distribution and activity. In flood conditions, root growth and efficiency are essential for crop productivity. The goal of this study was to investigate the effect of different irrigation regimes on the root development, yield and yield components of green pepper (green Hashemi cultivars). This study, which was based on a completely randomized design with three replications under greenhouse conditions, was done at Gorgan University of Agricultural Sciences and Natural Resources in 2016. Different irrigation regimes consisted of 3 levels (100, 125 and 150 percent of water requirement). The results showed that the effect of different irrigation regimes on root volume, root length, root area and number of fruit was significant at 1 percent level (P<0.01), but water use efficiency, and fresh and dry weight of fruit were significant at 5 percent level (P<0.05). The results also revealed that green pepper plants were sensitive to over irrigation. Increasing irrigation levels from 100 to 125 percent of pan evaporation resulted in the reduction of root volume, root length, water use efficiency, number of fruits, and pepper fresh weight to 20, 13.8, 26, 29and 6.4 percent, respectively. As the conclusion, with the increase in water irrigation level, the fresh weight of the fruit was significantly decreased.
R. Jamali, S. Besharat, M. Yasi, A. Amirpour Deylami,
Volume 22, Issue 3 (11-2018)
Abstract
The irrigation and drainage network of Zarrinehroud with an area of 65,000 hectares is the most important network of Lake Urmia basin, with the direct link to the lake. With the current crisis in the lake, an assessment of the existing network's performance is essential in the Urmia Lake Rescue Program. The purpose of this study was, therefore, to evaluate the transmission, distribution, and utilization efficiency and irrigation efficiency at the surface of the network. Three products were selected from the cultivar with the highest crop area (10% beet, 22% and 22%, and 38% wheat). The dominant method of irrigation was surface irrigation. At the network level, soil moisture in the field before and after irrigation, soil physical and hydraulic properties and water use volume for irrigation were measured. The results showed that the average transmission efficiency in canals with the concrete coating of the network was about 79%, which was in the range of 33% (in the smaller channels) to 100% (in the larger channels). The water distribution efficiency in the network was, on average, 76%, varying from 50% to 100%. Water use efficiency in the fields based on soil moisture balance analysis varied from 41% in the sandy loam soils to 66% for the clay texture. Based on the analysis of the data on the amount of harvest, production costs and product sales price, the water use efficiency (in kilograms of product per cubic meter of water used) varied from 0.4 for the elderly hay to 5.1 for the sugar beet. The amount of water used in this network (in Rials per cubic meter of water consumption) was between 2740 for alfalfa aged over 10 years and 6900 for wheat. It can be concluded that in the case of water constraints, wheat, sugar beet and alfalfa could be the most economic cultivar, respectively.
N. Salamati, H. Dehghanisanij, L. Behbahani,
Volume 23, Issue 1 (6-2019)
Abstract
In order to investigate the effect of water quantity in subsurface drip irrigation on water use efficiency of palm yield and yield components, and determining suitable irrigation treatments for three different date cultivars, a split plot experiment design in a randomized complete block design with three replications were applied for three cropping years (2013-2016), at Behbahan Agricultural Research Station. The applied irrigation water in three levels based on 75, 100 and 125 percent of water requirement in the main plots and three cultivars of Kabkab, Khasi and Zahidi dates were compared in sub plots. The irrigation level of 75% with 0.646 kg of dates per 1 cubic meter of water in terms of water use efficiency as compared to the other two levels of irrigation showed a significant superiority. The Khasi cultivar with 83.9 pips and 29.2929 fruits in the cluster ranked first. The irrigation level of 125% with 11.1% were higher in fruit moisture, and 100% and 75% irrigation levels with 9.6% and 7.8% moisture content were the next. The irrigation level of 125% for Kabkab cultivar with a volume of 11.1 cubic centimeters were ranked first. Optimizing water use and reducing it to 10606 cubic meters per hectare in irrigation level of 75% water treatment will save water consumption. If the basis for comparing the amount of water used in 100% water treatment is considered, then the use of subtropical drip irrigation reduces water consumption by 2509.6 and 5019.2 cubic meters per hectare, respectively, compared to 100 and 125% water requirements.
A. R. Alipour, S. H. Mosavi, A. Arjomandi,
Volume 23, Issue 2 (9-2019)
Abstract
Increasing the productivity and conservation of limited water resources in the agricultural sector, especially in the agricultural sub-sectors, is closely related to the revision of the traditional approaches of production system in the agricultural sector of developing countries. The aim of this study was to develop the optimal combination of crop production in Varamin Agricultural and Animal Husbandry Complex as one of the leading agricultural units in the agricultural sector of Varamin County with the emphasis on increasing water use efficiency. For this purpose, the statistical data and information of the 2015-2016 crop year of the complex were used in the framework of the multi-criteria decision making model. The results showed that in the optimum crop pattern in this unit, the priorities of maximizing net energy production and the annual profit as the economic goals would be significantly aggregated with the goal of increasing water use efficiency. Accordingly, in the optimum condition, net energy production was increased by 10%, gross profit was improved by 4%, and water use efficiency was promoted by 15%. Therefore, according to the results, it is suggested that, in order to achieve the economic aspirations and increase water use efficiency in Varamin Agricultural and Animal Husbandry Complex, wheat, alfalfa, silage and maize corn, based on the values calculated in this study, constitute the main combination of the crop production pattern.
B. Navidi Nassaj, N. Zohrabi, A. Shahbazi,
Volume 23, Issue 2 (9-2019)
Abstract
Integrated simulation of water resources systems is an efficient tool to evaluate and adopt various options in macro-policies and decision-making procedures that are in line with the sustainable development of drainage basins. One of the drainage basin management policies is to enhance the efficiency of agricultural land use. Considering the complicated function of the drainage basin elements and their interaction with each other due to water discharge fluctuations caused by various factors such as climate change, the evaluation of these policies is of great importance. Given the low irrigation efficiency in Iran, the present study was aimed to evaluate the effects of management scenarios (including long-term irrigation efficiency increased up to 20% with 5% intervals) and discharge fluctuation scenarios (including 5% and 10% decrease in the average basin inflows) on the reliability and vulnerability of water resources system in Dez Basin. The integrated scenarios were simulated in the WEAP model. The scenarios were separately simulated for the Dez irrigation network and all farmlands across Dez Basin. According to the results, reliability was decreased by 5.69 and 18.89% in the scenarios with 5% and 10% decrease in the average basin inflows, respectively. Furthermore, the irrigation efficiency of 20% in the scenario considering the current inflows ended up with the reliability of 73.58%. Moreover, in the scenario involving 5% decrease in the average basin inflows, the reliability was increased by 3.8% with an increasing efficiency of 20%; with 3.8% and 5.7%, there was an increasing efficiency of 15% and 20% in all farmlands, respectively. In the scenario consisting of 10% decrease in average basin inflows, the reliability was increased by 1.91%, 3.8%, and 5.7% with the increasing efficiency of 10%, 15%, and 20%; on the other hand, with, these were 3.8% 9.46%, and 13.2% with increasing efficiency in all farmlands, respectively. In all scenarios, the vulnerability was found to fluctuate between 25% and 31%, which was systematically analyzed.
M. Amerian, S. E. Hashemi Garmdareh, A. Karami,
Volume 24, Issue 3 (11-2020)
Abstract
Today, one of the biggest challenges facing the world is the lack of water, especially in the agricultural sector. In this research, we investigated the effects of irrigation method and deficit irrigation with the urban refined effluent on biomass, grain yield, yield components and water use efficiency in single grain crosses 704 maize. This research was carried out in a randomized complete block design with two irrigation systems (furrow irrigation (F) and drip irrigation (T)) and three levels of deficit irrigation treatments of 100 (D1), 75 (D2) and 55 (D3) percent of water requirements in three replications, in 2017, at the collage of Abourihan Research field, University of Tehran, in Pakdasht County. The results showed that the highest yield of biomass was 2.426 Kg m-2 for full drip irrigation treatments; also, there was no significant difference between D1 and D2 treatments. The highest grain yield was 1.240 kg m-2 for the complete drip irrigation treatment. The highest biomass water use efficiency was obtained for the treatment of 75% drip irrigation, which was equal to 5.3 kg per cubic meter of water. Therefore, a drip irrigation system with 75% water requirement is optimal and could be recommended.
N. Salamati, A. Danaie,
Volume 24, Issue 4 (2-2021)
Abstract
In order to study and evaluate the drought stress indices in surface irrigation by furrow method on grain yield, the yield components and water use efficiency, an experiment was conducted at Behbahan Agricultural Research Station in 2014-16. The experiment was conducted as a split plot in a randomized complete block design with 4 replications. Irrigation at two levels (irrigation after 100 and 200 mm evaporation from Class A pan, respectively) was evaluated as the main factor and corn cultivar was considered at 6 levels as the sub-factor. Comparison of the mean water use efficiency in irrigation and cultivar interactions showed 100 mm evaporation from Class A pan and cultivars V4 (PH1), V5 (PH3) and V2 (SC Mobin) were ranked the first and foremost, respectively, with the yields of 1.353, 1.299 and 1.296 kg of corn per kg of water consumed, respectively. The mean water consumed in 2014 of the experiment in 100 and 200 mm evaporation from Class A pan was 521.2 and 462.4 mm, respectively. Pearson correlation coefficient results also showed that with increasing the yield components, such as the number of grains per row and number of rows, the 1000-grain weight was increased due to the highly significant correlation coefficient of 1000-grain weight with grain yield (r = 0.8776). Consequently, grain yield was also increased. The highest values of SSI, STI, MP, TOL, GMP HM and YI indices were calculated in V4 (PH1). The higher values of the above indices in cultivar V4 (PH1) than other cultivars caused this treatment to be introduced as the superior one. The decreasing trend of corn yield, which was caused by water deficit stress, increased SSI, STI, MP, TOL, GMP and YI indices, while it decreased corn yield, leading to incremental changes in the YSI indices.
F. Haghnazari, M. Ghanbarian Alavijeh, A. Sheini Dashtegol, S. Boroomand Nnasab,
Volume 25, Issue 1 (5-2021)
Abstract
Changes in soil infiltration cause changes in irrigation efficiencies; therefore, estimating it in calculating irrigation efficiencies provides a more accurate estimate of irrigation performance indicators. In a study conducted on ARC2-7 farm in Amirkabir agro-industry in the 2010-2011 crop year, during four irrigations; two furrows were selected in terms of uniform infiltration and variable infiltration with a length of 140 and a width of 1.83 m. In the furrow assuming uniform infiltration two flume type II, at the beginning and end of it, were installed and the cumulative infiltration was determined by the volume balance method. The furrow with variable conditions was divided into four sections by installing five flumes. By examining the spatial variations of the mean cumulative infiltration, its value decreased from the first to the fourth section for the first irrigation by 15% and for the subsequent irrigations by 13%. Temporal changes of cumulative infiltration decreased by 27 and 30% for the first and second sections and by 26% for the third and fourth sections. An 11% increase in the average weight of the aggregate diameter and a 7% decrease in bulk density indicate physical changes in the soil. Surface runoff losses increased from 8 to 18.77% in the furrow assuming uniform infiltration and from 10.91 to 19.77% in the furrow with variable infiltration, and application efficiency decreased by 6%.
N. Salamati, A. Danaie, L. Behbahani,
Volume 25, Issue 2 (9-2021)
Abstract
To investigate and evaluate the effects of different levels of drip irrigation on grain yield and yield components, oil yield, seed oil percentage, and seed water use efficiency, an experiment was performed at Behbahan Agricultural Research Station during two crop years 2018-19 and 2019-20. The experiment was conducted in split plots based on a randomized complete block design with 3 replications. The amount of water in tape drip irrigation was compared at four levels of 40, 60, 80, and 100% water requirement in main plots and two sesame cultivars Local of Behbahan and Shevin in subplots from the beginning of flowering. Comparison of mean interaction effects of irrigation levels and cultivars showed that the treatment of 100% water requirement in the Behbahan local cultivar with the yield of 1218.0 kg/ha was ranked first and foremost. Water consumption in the highest treatment (100% water requirement and Behbahan local cultivar) was calculated to be 5389.4 m3/ha. Treatments of 100% and 80% of water requirement in superior cultivar (local Behbahan) with water use efficiency of 0.226 and 0.210 kg/m3 had no significant difference, respectively, and were in the first place. Pearson correlation coefficient calculated for the measured traits showed that the highest correlation of water volume was calculated (r = 0.9271) with the weight of one thousand seeds. Significant correlations of water volume with grain yield and yield components indicated that sesame was susceptible to drought stress and attention to optimal water management in sesame cultivation. Therefore, decreasing the volume of water consumed and consequently drought stress in sesame reduced yield and yield components.
F. Ghasemi-Saadat Abadi, S. Zand-Parsa, M. Mahbod,
Volume 25, Issue 4 (3-2022)
Abstract
In arid and semi-arid regions, water resource management and optimization of applying irrigation water are particularly important. For optimization of applying irrigation water, the estimated values of actual evapotranspiration are necessary for avoiding excessive or inadequate applying water. The estimation of actual crop evapotranspiration is not possible in large areas using the traditional methods. Hence, it is recommended to use remote sensing algorithms for these areas. In this research, actual evapotranspiration of wheat fields was estimated using METRIC algorithm (Mapping EvapoTranspiration at high Resolution with Internalized Calibration), using ground-based meteorological data and satellite images of Landsat8 at the Faculty of Agriculture, Shiraz University, in 2016-2018. In the process of METRIC execution, cold pixels are located in well-irrigated wheat fields where there is no water stress and maximum crop evapotranspiration occurred. The estimated maximum values of evapotranspiration using the METRIC algorithm were validated favorably using the obtained values by the AquaCrop model with NRMSE (Normalized Root Mean Square Errors) equal to 0.12. Finally, the values of water productivity (grain yield per unit volume of evapotranspiration) and irrigation efficiency were estimated using the values of predicted actual evapotranspiration using remote sensing technique. The values of measured irrigation water and produced wheat grain yield in 179 ha were estimated at 0.86 kg m-3 and 75%, respectively.
M. Abdi, H. Sharifan, H. Jafari, Kh. Ghorbani,
Volume 26, Issue 2 (9-2022)
Abstract
The irrigation schedule of crops is the most effective way to increase agricultural water use efficiency. In irrigation planning, determining the irrigation time is more important and difficult than determining the depth of irrigation water. Among all methods of determining the irrigation time of crops, the methods which used plants are more accurate than other methods. In this study, the wheat water stress index has been used which is based on the air vapor pressure deficit and the difference between vegetation and air temperature (Tc-Ta). First of all, the diagram and the relationship between the top and bottom baselines were extracted, then the water stress index of wheat was drawn in the Karaj region. Secondly, to determine the optimal water stress index of wheat, four treatments including I1: 30% of maximum allowable depletion of moisture, I2: 45% of maximum allowable depletion of moisture, I3: 60% of maximum allowable depletion of moisture, I4: 75% of maximum allowable depletion of moisture were performed in four replications. The amount of water stress index of each treatment was calculated during the season separately, and the CWSI of the treatment with the highest water use efficiency was used to determine the irrigation time of wheat. The results showed that the relationship between the upper and lower baseline for wheat in the Karaj region is Tc-Ta = 3.6 0c and
Tc-Ta = -0.27VPD - 2.64, respectively. The treatment of 45% of maximum allowable depletion of moisture had the highest water use efficiency and the optimal water stress index for wheat was obtained at 0.36 in the Karaj region.
M. Farzamnia, M. Miran Zadeh,
Volume 26, Issue 4 (3-2023)
Abstract
The present study was carried out in the Mahyar region of Esfahan Province to determine optimum drip tape spacing for the wheat crops on a silty clay loam soil respecting grain yield as well as yield components, water use efficiency, and variations in the salinity within the soil profile. The experiment was performed for three years from 2017 to 2019 with a randomized complete block design with three replicates and four treatments. The treatments consisted of three tape spacings (A) at 45, (B) at 60, (C) at 75 cm, and the Control (D) was irrigated with the basin method. The same volume of irrigated water was applied to the drip treatments, A, B, and C in every irrigation interval, whereas for treatment D, the local farmers’ practice was followed. Based on the results from compound variance analysis, the treatment effect on both grain yield and biological yield, and on water use efficiency and harvest index was significant at 1% and 5% level of confidence, respectively. The mean water use efficiency in treatments A, B, C, and D was measured as 0.79, 0.79, 0.73, and 0.78 kg m-3; thus, treatments A, B, and D outperformed treatment C. A comparison between the salinity of the soil profile at the beginning and the end of the growing season revealed that the basin irrigation method was more effective on salt leaching than the drip tape system. The results of this study indicated that concerning water use efficiency and crop yield, drip tapes spaced at 45 or 60 cm outperformed those which were 75 cm apart. On the other hand, the work required for irrigation system installation as well as the amount of drip tape residues left on the field at the end of the growing season is larger for tapes spaced at 45 cm compared to those which are 60 cm apart. This will have a significant impact on farmers’ budgets and environmental issues. Therefore, it is recommended to lay the tapes 60 cm apart for the irrigation of wheat crops on silty clay loam soils.
H. Jafarinia, A. Shabani, S. Safirzadeh, M.j Amiri,
Volume 27, Issue 2 (9-2023)
Abstract
Due to the climatic conditions of Iran, increasing water scarcity, and the effect of drought stress on the efficiency of irrigation water consumption and chemical fertilizers application, an experiment was conducted to investigate the effect of irrigation intervals (6, 9, and 12-day intervals), different levels of nitrogen fertilizer (200, 300, and 400 kg urea per hectare) and cultivation methods (on-ridge or heeling up and in-furrow) on yield and productivity of sugarcane as a factorial design based on randomized complete block design in 3 replications at Hakim Farabi Agro-Industry Company in Khuzestan province. The results showed that the maximum (106.73 tons/ha) and minimum (59.10 tons/ha) sugarcane yields were observed in 9-day and 12-day irrigation intervals, respectively. Also, the highest sugarcane yield (99.89 tons per hectare) was obtained in the treatment of 400 kg urea per hectare and the in-furrow planting method resulted in a higher yield compared to the on-ridge planting method. The highest water productivity in sugarcane stem yield and sugar production with 3.55 and 0.34 kg per cubic meter of applied water, respectively, was obtained in a 9-day irrigation interval. A significant increase in water use efficiency in sugarcane stem yield was observed in 400 kg urea/ha compared to the other two fertilizer levels. However, there was no significant difference in water productivity of sugar yield between different fertilizer treatments. The results showed that 6 and 9-day irrigation intervals in most of the studied traits were not significantly different. Therefore, using a 9-day irrigation interval is suggested in the studied area when the sugarcane cultivation area is high and the amount of available water is limited. In-furrow planting method can also be effective in reducing water consumption. Therefore, deficit irrigation and proper nitrogen fertilizer consumption can be very effective in sugarcane cultivation.
S. Aghaei, M. Gheysari, M. Shayannejad,
Volume 27, Issue 2 (9-2023)
Abstract
Due to water scarcity, it is impossible to utilize all irrigated cropland in arid and semi-arid areas. Therefore, dense cultivation with a drip irrigation system that delivers water directly to the plant's root zone is an appropriate choice to enhance water productivity. The objectives of the present study were to compare wheat yield and water productivity under two different water distribution patterns in the drip-tape irrigation system and surface irrigation in full irrigation and deficit irrigation levels. The experimental treatments consist of two irrigation systems (drip-tape (DT), and surface irrigation (SU)), and three different irrigation levels (a full irrigation level (W1), two deficit irrigation levels, the irrigation interval twice, and the same irrigation depth of W1 level (W2), applied half of the irrigation depth of W1 level at the same time (W3)). The SU was implemented in place with 100% efficiency to avoid runoff. The yield in full irrigation level in DT was 5338.4 kg/ha and in SU was 5772.8 kg/ha. Applying deficit irrigation in two irrigation systems has different effects due to various water distribution patterns. In the DT, the most yield reduction was in W2, and in SU was in W3. The highest water productivity in DT was observed in W3 with a 1.44 kg/m3 value. The highest water productivity in SU was observed in W2 with a 1.46 kg/m3 value. For each irrigation system, some type of deficit irrigation management is optimal.
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.
M. Saeidi Nia, H. Mousavi, S. Rahimi Moghadam,
Volume 28, Issue 1 (5-2024)
Abstract
Due to the lack of water resources and excessive evaporation in the country, it is necessary to have a detailed irrigation program and a suitable management method. The present research was conducted to investigate the effect of superabsorbent and mulch in Khorramabad in July 2022 in a factorial combination with a completely randomized design in three replications. The first experimental factor was irrigation water treatment in 4 levels including irrigation that provided 100% water requirement (I100), 80% of crop water requirement (I80), 60% of crop water requirement (I60), and 40% of crop water requirement (I40). The second factor included different corrective materials including plant mulch (M), superabsorbent (S), and control treatment (I). The results showed the maximum amount of wet and dry yield and crop height was related to I100-M treatment, i.e. 100 percent water requirement and compost corrective material, which were 89.52 tons per hectare, 29.42 tons per hectare, and 2.27 meters. The maximum wet and biological productivity for I40-S was calculated as 14.24 kg of wet matter per cubic meter of water and 4.75 kg of dry matter per cubic meter of water. The lowest wet and dry yields were related to I40-M, which decreased the yield of the control treatment by 6.5 percent and 0.9 percent. The lowest productivity was related to the I100-S treatment, which was calculated as 3.13 kilograms per cubic meter of water for biological productivity and 9.14 kilograms per cubic meter of water for wet weight productivity. In general, mulch had a better performance in the treatments where the water stress was low, but when the water stress increased, the performance of the mulch treatments decreased. In the superabsorbent matter, the treatments with complete irrigation or with less stress, yield decreased, but the treatments with increased stress showed better results than most of the corrective materials and the control treatment.
