مجله مدیریت آب و آبیاری
سال هفتم شماره 2 (پاییز و زمستان 1396)

Strategies for greater efficiency of water, especially in the agricultural sector is one of the most important strategies for improving water resources of Iran. The aim of this research is to achieve the best level of irrigation in irrigation methods for corn cultivation in Jouin city.This research were contracted in the research field Barkat company to the city Jovin on two varieties of maize (KSC 704, KSC barkat 3) growth period (135 days) This experiment using split split (split-split plot) in a randomized complete block design with 6treatments and four replications. The treatments include two sub-plots and sub-plots irrigation to full irrigation, deficit irrigation at two stress levels 75 and 50 percent of water requirements and irrigation tape two main treatments (T-tip) and furrow irrigation and stacking the two sub- treatments is the varieties type. The field irrigated by volume and is calculated based on data from pan evaporation. Results showed that deficit irrigation on water use efficiency, biomass water use efficiency , grain yield, were significant at P 0. It also reviews water use efficiency in the variate, KSC Barkat to 3 to 5 percent higher efficiency compared to single cross 704

This study was conducted to investigate the effect of vermicompost on soil physical properties in two treatments with three replications, by using of vermicompost and control treatment in two soil layers 30 and 60 cm under irrigation with unconventional water at Agricultural and Natural Resources Campus of Razi University in 2016. The effect of vermicompost on soil physical properties including bulk and practical density (ρb and ρa), porosity (n), saturated hydraulic conductivity (Ks), soil moisture characteristic curve, field capacity (θFC), permanent wilting point (θPWP) and available water (AW) were evaluated. The results showed that the use of vermicompost significantly increased soil hydraulic conductivity and permanent wilting point but did not have significant effect on the other properties. The vermicompost increased the saturation hydraulic conductivity in two layers as 22.2 and 43.5 percent respectively and had a positive effect on soil moisture characteristic curve. Also, in vermicompost treatment, moisture content in the first and second layers increased at field capacity 21.1 and 21.5, at permanent wilting point 32 and 24 and at available moisture 9.3 and 18.6 percent, respectively. Vermicompost increased the bulk density of the first and second layers as 7.3 and 7 percent, but reduced the practical density 2.1 and 1.2 and the soil porosity as 18.9 and 18.2 percent, compared to control treatment.Finally, the results showed that although vermicompost statistically did not change more soil physical properties but in general improved soil physical conditions.

Effect of surface and subsurface drip irrigation methods on yield and water use efficiency of two nectarine cultivars
This study was conducted with the purpose of investigation the effect of different amount of water on yield and water use efficiency (WUE) of nectarine (Prunus persica L. cv. "Sun Gold" & “Quota”) trees. A split plot experiment was laid out in a completely randomized block design including 3 different levels of water treatments with three replication. Treatments were including different amount of water (60, 80 and 100 Percent water requirement) in main plot and drip irrigation method (surface and subsurface) in sub plot. Results showed that in cultivars, interaction water percent and irrigation method had not significant effect on yield and WUE. In "Quta ", the highest (44.067 ton/ha) and lowest (40.100 ton/ ha) yield were obtained with 100 and 60 Percent water requirement respectively. There were not significant differences on yield in surface (45.044 ton/ha.) and subsurface (38.211 ton/ha) irrigation method. In "Sun Gold", the highest (46.7 ton/ha) yield were obtained with 100 percent water requirement. With reducing amount of water, there were significant differences on yield. Surface drip irrigation method with 41.644 ton/ha was the better of Surface drip irrigation method with 39.000 ton/ha.

In recent decades, the use of exotic water in agricultural areas, is considered as one of the best models of management. One of the exotic water, is saline and brackish water. Currently, several methods are considered for the use of saline water in irrigation. The present study aimed to compare existing approaches and propose a new approach on how to conjunct saline and non-saline water. Forage sorghum plants were grown in field conditions. Treatments consisted of; control treatment (100% sweet), the half treated, the alternate time, the alternate place, the mixed and one hundred percent saline treatment. In each of these treatments, half of the needed water for irrigation will be provided with saline water. Finally, the biological parameters of the plant and salinity changes in the soil profile, were analyzed. The results show that the best performance refers to alternate treatment, although after control treatment Then, the alternate place are, the half treated, the alternate time and the mixed treatment.

Drought and its stress are the most important factors for crop production. This research was carried out for determination of crop water production function and investigation different levels of irrigation water on yield component total dry matter, grain and harvest index in different irrigation levels for corn in Khoozestan in a research farm in Islamic Azad University, Dezfool branch in 1014-2015. It was conducted in randomized complete block design with four treatments including 60%, 80%, 100% and 120% of full irrigation (W60, W80, W100 and W120, respectively) and four replications. According to the total dry matter, grain and shot, the best crop water production function was obtained as linear function with R2 equal 0.897, 0.682 and 0.927, respectively which was significant in level of 1%. In comparison to W60 treatment, full irrigation treatment (W100) increased total dry matter yield (70%) but in comparison to W100, W80 treatment decreased total dry matter yield (5%). On the basis of total dry matter yield and grain (4.8 and 2.06 kg/ m3), maximum harvest index (0.43) and maximum water use efficiency were obtained for W80 treatment. The results show that the best grain yield and water use efficiency were related to W80.

In order to study the effects of deficit irrigation on yield of tomato, an experiment was conducted in Jiroft. The experiment treatments were arranged as randomized complete block design with three replications. The irrigation regimes consisted of full irrigation, regulated deficit and partial root zone drying irrigation (RDI75, RDI55). The results showed that deficit irrigation resulted in water saving at the rates of 16-34 percent. The highest yield (202.65 ton/ha) was produced by full irrigation. There was no significant difference between yield and fruit weight of full irrigation treatment and 75 percent water replacement in partial root zone drying. The highest water use efficiency was 45.6 kg/m3 was obtained in 75 percent water replacement in partial root zone drying. Also, despite the same water consumption of 75 percent water replacement in partial root zone drying and regulated deficit, yield was decrease 16.1 percent. Therefore, it can be concluded that 75 percent water replacement in partial root zone drying, which resulted in a non-significant decrease of yield and while resulting in a 25 percent decrease in water use and increased 14 percent of water use efficiency, would be a promising water-saving method as in Jiroft.

Considering the critical conditions that have occurred in recent decades for water resources of the country, agricultural managers are considering developing micro-irrigation systems in agricultural lands, so for their sustainable development and utilization, the evaluation of these systems is necessary. In this regard, the technical and hydraulic performance of 9 irrigation systems in Isfahan province was evaluated. In this experiment, some field measurements were taken to obtain the required parameters for system evaluation. Assessments were made based on the SCS guidelines. The results obtained from the calculation of the evaluation parameters show that amounts of coefficient of emitter discharge variation (qvar) was less than 10% for 33% of the projects, ranging from 10 to 20% for 44 percent of the projects, and over 20% for the rest of the projects, qualified as favorable, acceptable and unacceptable, respectively. The amounts of distribution uniformity (DU), in 22% of projects was more than 90%, 55% between 80 to 90% and the rest between 70 to 80%, qualified as excellent, good, and fairly good. The potential application efficiency of low quarter (PELQ) and application efficiency of low quarter (ALEQ) were between 42.4 to 78.1 % and between 47 to 81.5 percent, respectively, which is moderate. Inappropriate pressure in blocks, deficient skills of the operators, dripper clogging, and lack of proper maintenance for filters, reduce PELQ and AELQ in some projects.

In order to determine the production function of water and nitrogen fertilizer for onion plant in Three irrigation methods, an experiment based on split plot design was carried out with three replications at research farm in Zahak for two years. The research factors included irrigation by three methods (furrow irrigation, surface drip and subsurface drip), four levels of irrigation water (120, 100, 75 and 50persent water requirement) and four levels of nitrogen fertilizer 100, 75, 50 and 25% nitrogen). In order to determine the optimum depth of water and fertilizer, the best function of onion production was selected from four production functions (linear, logarithmic, quadratic and transverse) for all three irrigation methods. In all three irrigation methods, the quadratic function was selected as the superior production function. The average final production index relative to the depth of irrigation water in furrow irrigation, surface drip irrigation and subsurface drip irrigation was 0.23, 0.34 and 0.37 ton/ ha respectively, and the final production index relative to nitrogen was 0.09, 0.21 and 0.22 ton/ha respectively. The ratio of the technical replacement rate of nitrogen fertilizer instead of the amount of irrigation water was determined to be 39.9, 0.61 and 0.6 kg respectively.

Water crisis is a main factor of crop cultivation limit in growing season. For different ‎crops, knowledge of sensitive irrigation timing is necessary for maximizing yield and amount of ‎irrigation water. Thus in order to investigate the effect of water stress on different growth stage of ‎maize, a field study was carried out during 2009 to 2011 growing season in Mazandaran province. ‎Experiment was‏ ‏conducted using randomized complete block design with four replications and ‎nine treatments. Irrigation treatment was tested with 30, 60 and 90% water depleted before and ‎after flowering stage. The amount of irrigation water was determined by weighing method to ‎reach soil moisture to the field capacity. The results of the comparison of the three-year average ‎yield showed that the highest yield (13400 kg ha-1), water use efficiency (3 kg /m3) and irrigation ‎water use efficiency (4.25 kg /m3) were obtained by 30% water depletion before and after ‎flowering stage treatment. In general, it can be concluded that increased stress before flowering ‎had a significant effect on yield and water use efficiency of maize. So, the increase in stress ‎before flowering caused a more severe reduction in the yield and water use efficiency of maize.‎

This research was conducted to evaluate AquaCrop model to simulate sugar beet yield and water use efficiency (WUE). In this research, data from two sugar beet cultivars were used at Shahrekord Agricultural Research Center. Treatments were consisted of water deficit (in five levels: E0: 100%, E1: 85%, E2: 70%, E3: 55%, and E4: 30%) in different growth stages (T1: initial, T2: T2: mid-season, and T3: late season). AquaCrop had a low sensitivity to change in PWP moisture and minimum temperature values and high sensitivity to change in crop coefficient for transpiration values. The yield results of RMSE and NRMSE were 0.57 and 0.11 ton.ha-1, respectively. The yield results for two statistics criteria (EF and d) were 0.62 and 0.99, respectively. Evaluation of AquaCrop revealed that this model had good accuracy for simulation of sugar beet yield and WUE.

One of the major problems in dry countries such as Iran is water and soil salinity. Deficiencies in water resources have led to the use of saline water for irrigation in agriculture. In order to study the effects of salinity stress on seed, oil and protein yield of Camelina, a randomized complete block design factorial experiment with three replications was designed in a research greenhouse. The factors included 4 lines Camelina (80, 115, 130 and 131) and 5 saline levels (0.6, 3, 6, 9 and 12 dS/m) and the control sample was rainfed condition. The results showed that by increasing salinity levels, grain yield and its components decreased significantly but there were no considerable differences between Camilina lines at all. In addition, the results showed that the seed, oil and protein yields in rainfed conditions is more than that of irrigation with 12 dS/m salinity, and it suggests that the cultivation of this plant in the rainfed conditions is not economically efficient for more than 9 dS/m salinity condition.

Advance time is one of the most important factors, especially for determining irrigation timing. This project has been conducted for determining and evaluation of furrow advance time in two irrigation management including conventional and alternative furrow irrigation. Four different inflow rates within two periods of Maize growth stages for two furrow irrigation management were considered. Results showed, the water advance time in conventional furrow irrigation in two growth stages with inflow rate as 0.15, 0.28, 0.35 and 0.46 l/s were 1.8, 2.4, 1.6 and 1.6 times respectively comparative to alternative furrow irrigation. Also results in end of season revealed that with increasing inflow rate the advance time in conventional furrow irrigation were 1.3, 1.6, 1.4 and 1.5 times as comparatives to a conventional furrow irrigation. Soil surface moisture variation showed that the soil moisture content in alternative furrow irrigation decreased about 28% in comparison with the conventional furrow irrigation. With increasing furrow inflow rate the coefficients of advance power function (r & p) increased about 4 and 56% for conventional and 12 and 26% respectively alternative furrow irrigation.