javad ramezani moghadam

It is crucial to assess the groundwater quality in each region. This study focused on evaluating and analyzing the groundwater quality of the Ardabil plain. To achieve this, 32 water samples from various wells were collected and elements and quality parameters (such as electrical conductivity, acidity, sodium, magnesium, chlorine, bicarbonate and water hardness) were measured. Groundwater quality was investigated using Gibbs diagram and Cluster analysis. Gibbs ratio I and II ranged from 0.11 to 0.83 and 0.16 to 0.86, respectively, with an average of 0.36 and 0.57. Most of the water samples fall in the zone of rock dominance. Also, based on the cluster analysis, the quality of the first and second clusters (in Schuler's diagram) were placed in the good and poor range for drinking purposes, respectively. On the other hand, based on Wilcox's classification, the studied groundwater was divided into four classes, and the best quality was C2-S1 class (almost suitable for cultivation). In addition, it can be concluded that the quality of groundwater in the second cluster is not useful for agricultural and drinking purposes, but the first cluster was almost suitable for agricultural and drinking purposes.

Pollution and declining quality of water resources reduce usable water resources, weaken economic development and threaten human health. In this study, groundwater quality was studied and analyzed in Ardabil aquifer. For this purpose, 32 samples of groundwater sources in the Ardabil plain were collected and the concentrations of major ions, minor ions and some heavy metals were measured. Then, hydrogeochemical factors affecting the groundwater quality of the study area were analyzed using multivariate statistical methods, including correlation coefficients and factor analysis. According to the correlation matrix, the concentrations of metals such as arsenic, barium, scandium, silicon, zinc and vanadium indicated a little correlation with the main ions. Therefore, it can be concluded that the entry of these elements into groundwater is due to human activities. In factor analysis, the groundwater quality changes were affected by four main factors with 77.31% of the total variance of data in Ardabil plain. The results of factor analysis showed that the first factor was lithogenic, the second and third factors were lithogenic and anthropogenic, and the fourth factor was just anthropogenic. The results showed that the concentrations of heavy metals such as arsenic, barium, scandium, silicon, vanadium and zinc did not have a high correlation with the main ions, so the presence of these elements could be due to human activity. Also, the greatest effect on groundwater hydrochemistry in the study area was related to magnesium, sodium, calcium ions and electrical conductivity.

Due to the severe shortage of fresh water in arid and semi-arid regions, farmers are forced to use deficit-irrigation techniques along with salt water. In order to minimize salinity and water stresses impacts on the yield and yield components of spinach plant, separately and mutually, a pot experiment was performed from November 2, 2018 to January 18, 2019. The experiment was performed as factorial in the form of a completely randomized design with four replications including three irrigation levels (consisting complete irrigation 100% water requirement =W1, W2=75% W1, and W3=50% W1) and three salinity factors (drinking water S1=0.75, S2=4, S3=8 dS/m) in Kashmar's arid climate. The results showed that separate salinity and deficit irrigation stress had a significant effect on the plant traits including the wet weight of aerial part, leaf surface, plant height, stem height, root length, the dry weight of aerial part and the dry weight of the root, but the mutual effect of salinity and deficit irrigation on the mentioned traits was not significant. As salinity and deficit irrigation increased, the morphological properties of the plant decreased; for example, the maximum wet weight of the plant's aerial part was 147.15 grams in the plant related to W1S1 treatment and its minimum was 38.36 grams in the plant related to W3S3 treatment. The results of comparing the average of plant growth traits showed that there was no significant difference between the treatment of 100% water requirement with salinities of 0.75 and 4 dS/m, but in the salinity treatment control (0.75 dS/m) there was a significant difference between various levels of deficit irrigation. In regard to the above results, it can be said that spinach plant is more sensitive to water stress than salinity stress and applying water stress to the plant during the growing season should be avoided

 Nowadays, the decrease of water resources and increasing salinity of irrigation water are evident in most parts of Iran. Increased salinity of irrigation water can impair plant metabolism, decrease biomass and stem length. On the other hand, water stress decreases root length and weight and crop yield. One way to reduce the negative effects of moisture stress is management of irrigation time. This can be investigated by changing the percentage of moisture permitted depletion and selecting the one with the lowest yield depletion. On the other hand, the amount of damage to the crop can be reduced by examining different amounts of water salinity and its effect on crop yield. Therefore, in this study, the effects of different amounts of irrigation water salinity and irrigation time management on tomato yield under greenhouse conditions were investigated.

 This study was carried out in greenhouse (No. 2) of Faculty of Agriculture and Natural Resources of University of Mohaghegh Ardabili. In this research, the effect of different values of salinity (in different irrigation times) on root characteristics and yield of tomato (Saint Pierre cultivar) was investigated. The experimental design used in this research was a factorial experiment in a completely randomized block design with four replications. The applied treatments included salinity of irrigation water (four levels: S1=1.5ds/m, S2=2.5ds/m, S3=4ds/m and S4=7ds/m) and irrigation time management stress (in three levels, irrigation at 40, 50 and 65% field capacity, respectively, I1, I2, I3). The pots used in this study were incomplete cones with a height of 27 cm, a span diameter of 26 cm and a bottom diameter of 19 cm. In this study, indirect method (transplanting) was used for cultivating tomato. After cultivating the transplants in prepared pots, they were irrigated with pure water for two months to stabilize the transplants in order to avoid any stress effect on the transplants. The moisture meter (Model: PMS-714) was also used to measure daily soil moisture of the pots. Statistical analysis was performed by MSTATC software. The important characteristics investigated in this study were root length, root weight (dry and wet), root diameter and volume, plant yield, water drainage, evapotranspiration and water use efficiency.

According to the results of this study, salinity values of irrigation water had a significant effect at 1% level on fresh and dry root weight, root diameter and volume, total evapotranspiration, total water use, total water drainage output, crop yield and the number of blooms. On the other hand, irrigation water salinity had no significant effect on the number of unripe fruits at 5% confidence level. For example, the highest fresh and dry weight of roots were 26.17 and 6.3 g for S2 treatment, respectively. However, the difference in root weight values for S2 and S1 treatments (Mean equal to 27.5%) was not significant. Also, with increasing salinity of irrigation water above 2.5 dS/m, root weight (dry and fresh) decreased significantly (at 1% level). The reason for the decrease in root weight at high level of salt concentrations can be due to the accumulation of salt (including potassium, sodium, etc.) in various organs of the plant including the root. On the other hand, the results showed that the effect of irrigation time management was significant only on root diameter and weight of ripe fruit at 5% and 1%, respectively. According to the results of this study, irrigation can be achieved with 50% moisture allowable depletion instead of 40% moisture permitted depletion without significant change in the weight of ripe tomato fruit. This can certainly cause saving of irrigation water that can be very effective in the current condition of Iran and lack of water resources. In this study, the relationship between evapotranspiration and crop yield and the relationship between these parameters, were investigated. Results showed that, tomato yield coefficient of response to moisture stress (Ky) varied from 0.4 to 1.20. Also the average response coefficient of tomato to water stress was 1.12. This value was close to the mean Ky provided by the FAO (Ky = 1.05). The slight increase in Ky value obtained from this study is probably due to the salinity stress applied to the tomato plant.

 This study was conducted to investigate the effect of salinity stress on yield and root characteristics of tomato under irrigation time management and greenhouse conditions. The results showed that the effect of irrigation salinity was significant on yield, yield components and root characteristics (e.g., root weight, diameter and volume, yield, evapotranspiration and drainage output). On the other hand, moisture stress induced by irrigation time variation had no significant effect on yield, yield components and root characteristics of tomato except in two cases. This study indicated that the effect of salinity irrigation water is more effective than water stress on reduction yield. Also, according to the results of this study, the use of 2.5 dS/m irrigation water salinity instead of 1.5 dS/m in most cases had no significant effect on yield reduction but may also increase it. The results of this study show that under current conditions of Iran (increasing quantitative and qualitative shortage of water resources) it is possible to use lower quality waters such as treated wastewater and agricultural wastewater (with management of salinity and leaching) to achieve the acceptable yields for crops.

Grouping of catchments based on their climatic factors and physiographic characteristics is a prerequisite for regional analysis of runoff and its use for estimating discharge of catchments without discharge measurement station. In this study, catchments located in Ardabil province were separated into homogeneous hydrological zones using discharge, mean annual precipitation and physiographic characteristics of catchments and hierarchical clustering method. Due to the large number of parameters, by using principal component analysis, the first four components with 83.6% of total variance were selected as inputs for cluster analysis. Then, the optimal number of clusters was determined by using hierarchical method and drawing the tree diagram, and finally the final clustering was done by K-means method. Subsequently, the sub-catchments that followed a hydrological process were identified using the Dalrymple uniformity test. The results of the uniformity test showed that by excluding stations outside the confidence limits of each cluster, catchments that were similar in terms of annual discharge and other physiographic and meteorological parameters were clustered. Therefore, the number of sub catchments located in clusters 1, 2, 3 and 4 were 8, 4, 9 and 9 catchments, respectively, which can be used in regional analysis to estimate runoff and floods in catchments without discharge measurement data.

The largest share of water consumption in Iran is related to the agricultural sector. Therefore, in order to save water resources, priority is given to reducing irrigation water consumption. On the other hand, reducing of water quality and salinization are the main problems which are commonly found in the areas with limited water resources. One of the most important effects of salinity is the reduction of yield and its inhibitory effects on plant growth and metabolism. Also, increasing salinity can reduce potassium, calcium and magnesium ions. One of the significant points regarding the effects of salinity stress is a significant decrease in the hydraulic conductivity of the roots, which leads to a decrease in the water use efficiency index. According to the food and agriculture organization (FAO), more than 40 percent of Iran's irrigated lands are affected by salinity stress, which is generally found in dry and semi-arid areas. Therefore, studying the combined effect of stress caused by salinity and water stress can be used to provide management solutions for irrigation and crop production.

This study was conducted in greenhouse laboratory at University of Mohaghegh Ardabili, Ardabil, Iran during August to November 2016. In this research, the effects of saline water on cherry tomato yield under water stress conditions were investigated. The applied treatments included irrigation with saline water (in two levels: S1=4ds/m and S2=7ds/m) and water stress (in three levels, irrigation at 40, 50 and 65% field capacity, respectively, I1, I2,I3). The experimental design used in this research was a completely randomized block design with four replications. On the other hand, in order to compare the plant yield under water stress and salinity conditions with non-stress conditions, control treatment with salinity characteristics less than 1ds/m and irrigation without water stress were used in three replications. In this experiment, cherry tomatoes were cultivated in the pots with diameter and height of 26 and 27 centimeters, respectively. The moisture meter (Model: PMS-714) was also used to measure soil moisture and determine the irrigation time. The most important parameters included cherry tomato yield, total evapotranspiration and water use efficiency index. It should be mentioned that analyses of the results were done by MSTATC software (Version: 2.10).

The results of this study showed that the interaction between two factors of water and salinity stress on the parameters was not significant, but the effects of salinity stress on yield, total evapotranspiration and water use efficiency (in two levels: 2% and 5%) are significant. Also, the greatest effect of salinity stress on cherry tomato yield was observed, so that by increasing the amount of irrigation water salinity from 4 to 7 ds/m, the yield was decreased by 27%. Also, the performance in salinity treatments of S1 and S2 decreased by 27.2% and 46.7%, respectively, compared to the controled treatment. Probably the reason for the yield reduction caused by decreasing in plant evapotranspiration and plant growth and metabolism. In addition, water use efficiency index in treatments of S1 and S2 decreased by 3.4% and 22.3%, respectively, compared to the controlled treatment. As it can be seen, the differences in water use efficiency between the control and S1 treatments were not significant. In this study, the average values of Ky (plant response coefficient to salinity and water stresses) were achieved 1.39, which was higher than the value that was reported by FAO for tomato plant under water stress conditions (equal to 1.05). This can be due to the significant effect of saline irrigation water on the yield of the tomato plants. Finally, based on the results of this research, it can be said that although salinity decreased yield significantly at 1% confidence level, in the coming years, with severe water resource constraints and increased costs for its preparation, this yield loss can be economical and feasible.

In this research, the effect of saline water on cherry tomato yield under water stress conditions was investigated. According to the results of this study, with increasing salinity of irrigation water from 4 to 7 ds /m, total evapotranspiration decreased by 10%. On the other hand, due to salinity stress, tomato yield was decreased to 27% in the most salinity levels of irrigation water compared to control treatment; one of the main reasons of which could be the reduction of total evapotranspiration in the growing season. In the end, the important point to note is that although, based on the results of this study, utilization of irrigation saline water decreased the yield, total evapotranspiration and water use efficiency by 27%, 8.9% and 19.2%, respectively compared to the control treatment, but in the near future, by increasing the water production costs and the quantitative reduction of water resources, even use of saline water is economically feasible and justifiable.

The quantitative and qualify limitations of agricultural water resources and fertilizer management are the important problems in Khuseztan Province. This study was conducted to evaluate the effect of deficit irrigation and different nitrate levels on the maize yield. The treatments were included irrigation (100, 75 and 50 percent of irrigation requirement) and urea fertilizer (300, 375 and 450 kg/ha). The experiment was carried out in the framework of a factorial using randomized complete block design with three replications. The result showed that the biomass, plant maximum height, grain yield and harvest index significantly increased (P>0.01). Also the results showed that in the 100 percent irrigation level, grain yield and biomass increased 6.6% and 4% ,respectively, to compared with the free drainage. The results illustrated that the use of groundwater can be decreased water drainage entrance into the surface resource as well as increased plant yield.

Difficulties like production, transportation , performance and etc in sandy envelopes which have been used in subsurface drainage projects have innovated artificial envelopes At this research performance of the artificial envelope PP450 produced in two Iranian factories (called A and B) came under close observation and compared with the same foreign grade. For these reasons first with Komo Standard Tests the artificial envelope came under loading process and the amount of sand passed into every artificial envelope measured. Results of soil/sand tank showed the out flow fluctuation on the first second and third day was high but it decreased after that and got stable (94, 66, 72((mlit/min)/m) respective related to the foreign envelope , envelope A and envelope B). Total maximum and minimum average of the out flow discharge related to the foreign envelope and the envelope A.Comparison of water resistance around the drainage pipe showed that the foreign artificial envelope has the minimum entrance resistant(2.03 day/m). Minimum and maximum amount of sediment in the pipes related to ,putting in order, the foreign envelope and envelope A. but in sum there was no major difference on the amount of sediment, the maximum difference 20% is its indication.Finally this research passes and confirms the envelopes produced inside but recommends more study on them , specially envelope A, in order to get a better quality.

Discharge of emitters changes by various factors such as pressure, manufacturing coefficient of variation, clogging and the temperature of water irrigation. In order to study the effects of temperature on discharge of emitters, 10 types of emitters have been tested in irrigation laboratory in Faculty of Water Sciences Engineering Ahwaz, ShahidCharmUniversity. In this research, the effect of 4 different temperatures i.e. 10, 20, 30, 40°C under 4 pressures i.e. 5, 10, 15, 20 m was reviewed. By calculation of manufacturing coefficient of variation and based on American Society of Agricultural Engineers Standard, qualitative classification of emitters was done. Finally, four type were excellent, two of them unusable and the others were between both conditions. For experiments in temperature of 10° , the ice and in temperatures of 30° and 40°, a tank equipped with an electric heater and controlling unit for temperature was used respectively. With regard to obtained results by raising temperature of irrigation water, the discharge of non-compensating emitters was increased. In compensating emitters, the temperature didnt have significant effect on discharge of emitters in 3 cases, but in two types cause discharge was decreased and in one, discharge was increased. In final, result showed that temperature doesnt have a significant effect on manufacturing coefficient of variation and water emission Uniformity.