جستجوی مقالات مرتبط با کلیدواژه « Deficit irrigation » در نشریات گروه « آب و خاک »

In order to investigate the effects of drought stress and different LED lights spectra on yield, water productivity and morphologic characteristics of wheat plant, a factorial experiment was performed in the form of completely randomized design in 2022 in the university of Torbat-e Jam, The effects of drought stress include three levels (100, 75 and 50 percent of water requirements) and the effect of different light spectra including six levels (white, 70% red + 30% blue, 100% red, 70% blue + 30% red, 100% blue and 50% red + 50% blue) on wheat plant was investigated. The results showed that by applying drought stress to the amount of 75 and 50% of the water requirement of the plant, fresh weight of aerial parts, dry weight of aerial parts, root fresh weight, root dry weight, plant length, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, potassium, phosphorus and magnesium concentration decreased and water productivity increased by 18.52% and 27.94% respectively. Also, the results showed that among the different types of LED light spectra application, the highest amount of fresh and dry weight of aerial parts, fresh and dry weight of roots, plant length and water productivity in 70% red + 30% blue light and the highest amount of photosynthetic pigments parameters were obtained in wheat plant under 50% red + 50% blue light. the results showed that the highest concentration of potassium occurred in 100% red light, phosphorus concentration in white light and magnesium concentration in 50% red + 50% blue light.

Due to the location of Iran in arid and semi-arid regions and according to the quantitative and qualitative limitations of water resources, optimal management and volumetric delivery of water is important in irrigation and drainage networks. In this regard, it is necessary to estimate the water requirement of crops accurately and provide adequate water to farmers. Remote sensing technology provides facilities that can be used to obtain different layers of information at the lowest cost in the fastest time. Accordingly, many researchers have used remote sensing data to monitor vegetation cover, provide land use maps, estimate crop evapotranspiration and have declared this technology as appropriate tool for such studies. Based on the previous studies, it is observed that low researches has been conducted to investigate the crop evapotranspiration considering the crop water requirement. Therefore, the most important objectives of this study are: provide the cropping pattern and land use maps using Sentinel 2 satellite images, determination of the water requirement for the delivery points of irrigation network, determination of the actual evapotranspiration of the crop cover using SEBAL algorithm and Landsat 8’s images and finally evaluation of the water supply and management in the Mahabad irrigation and drainage network. In order to determine the cropping pattern of the Mahabad irrigation and drainage network, Sentinel 2 images have been used related to the 2018-2019 crop year. The images were examined in terms of the region of syudy and the percentage of cloudiness and after selecting the appropriate images, pre-processing operations including radiometric and atmospheric corrections were applied on them. Then, the NDVI index was calculated based on selected images. On the other hand, after determination of the classification classes, the phenological cycle of crops were examined for each class and spectral pattern of crops was determined during the growing season. Training samples were selected for supervised classification using the existing maps, Google Earth images, creating images with false color composites and considering the growth pattern and some of them were also considered for validation of the classified map. Then, the cropping pattern map was obtained by using the SVM classification algorithm. After generating the crop classification map, the water requirement of the different classes was determined based on the Penman-Montith evapotranspiration method, applying plant coefficients and irrigation application efficiency at the volumetric water delivery points. Finally, the actual evapotranspiration rate of the study area calculated based on the SEBAL algorithm and compared with the net water requirement map. Based on the results, kappa coefficient and overall accuracy of the classified map were determined to be 0.953 and 91%, respectively. The area of the planted agricultural farms was equal to 10594 hectares and 1576 hectares of farms were without planting. The area of orchard farms was equal to 6786 hectares and the area of sugar beet, wheat, alfalfa and corn lands were obtained to 998, 1839, 693 and 278 hectares, respectively. Thus, the net irrigation water requirement was equal to 71 million cubic meters and the gross irrigation water requirement was calculated equal to 161.36 million cubic meters, considering the irrigation efficiency of 44%. On the other hand, the evaluation of the SEBAL evapotranspiration maps during the growing season indicated that the total amount of evapotranspiration was equal to 79.78 million cubic meters, and this amount was 14% higher than the net irrigation water requirement. Finally, according to the crop classification map and based on the comparison of the net irrigation water requirement and evapotranspiration maps, the water consumption in the Mahabad irrigation and drainage network was evaluated. It turned out that in the upstream farms of the network or close to the Mahabad River, the Water consumption was more than net water requirement and downstream areas were faced to deficit irrigation due to lack of sufficient water.Finally, based on the results of this study, it was observed that by using the capabilities of satellite images and remote sensing, it is possible to monitor and evaluate the condition of agricultural farms on a large scale with acceptable accuracy. Also it is possible to improve the management of water supply and water use efficiency in irrigation and drainage networks by creating up-to-date land use maps, determining net and gross irrigation water requirment and comparing with actual evapotranspiration maps.

Camelina is an oilseed plant that could produce proper yield in arid and semi-arid areas with low water consumption. To investigate camelina response (Sohail cv.) to application of different amounts of irrigation water, this study was conducted in 2022-23 in Khatam District, Yazd Province. Treatments included drip tape irrigating based on 100% (full irrigation as control), 75% and 50% of full irrigation. Results showed that the effect of irrigation treatments on biological yield, grain yield, harvest index, plant height and protein percentage of camelina was significant (p<0.05). However, by reducing the volume of irrigation water, biological yield decreased significantly, such that biological yield of 75% and 50% treatments decreased by, respectively, 18.3% and 46% compared to the control treatment. The highest grain yield (2373.3 kg ha-1) was obtained with the application of 2384 m3 ha-1 irrigation water (control). By reducing the amount of irrigation water by 75% and 50%, grain yield decreased by 31.4% and 40.0%, respectively. The harvest indices were 22.6%, 19.0% and 25.1% for 100%, 75%, and 50% treatments, respectively. The highest plant height was 90 cm for the control treatment. The water productivity ranged from 0.88 kg m-3 for 75% treatment to 1.04 kg m-3 for the full irrigation. The highest proline content was observed for the treatments of reducing the volume of irrigation water, in which the amount of proline increased by 1.4 times compared to the control treatment. The results showed that the amount of irrigation water required for camelina was lower compared to the common winter crops, especially in tape irrigation method. Therefore, this plant could be used as a low water-demanding for delayed planting in winter season.

Leaf area index (LAI) is one of the most important parameters in plant growth studies, which has a direct relationship with the amount of light absorption, photosynthesis, plant physiological indicators, yield, etc. to be In this study, different growth functions such as Gompertz, Gaussian, polynomial and logistic were used to model silage maize leaf area index (as a dependent variable) based on growth degree days (as an independent variable). The studied treatments included pulse irrigation and continuous irrigation, each at three levels of MAD equal to 100, 80 and 60%, which were applied as a completely randomized block design. The results showed that based on R2, NRMSE and EF parameters, all four used models were highly accurate and precise in estimating the leaf area index during the growth period. Among the four investigated models, the logistic model showed the best result among different irrigation managements and levels. Also, this model had the highest efficiency among both continuous and pulse irrigation treatments, in MAD equal to 100%. The results of this study can be a basis for monitoring crop growth and evaluating different managements in the water, soil and plant chain, and finally a useful tool for management and planning to achieve food security.

As it has been for several years, drought conditions in various regions of Iran, including the central part of Marvdasht city in Fars province, have been very noticeable and have led to a severe decrease in the quantity and quality of groundwater, resulting in severe restrictions on agricultural production. Therefore, the farmers in the region have spontaneously turned to planting drought-resistant trees such as olives and pistachios. On the other hand, due to the significant reduction in the quantity and quality of groundwater in the study area, the quantitative and qualitative parameters of the fruit of the region's agricultural products, especially olive trees, which are irrigated under these conditions, are effective. It can be said that the quality parameters of olives increase with low irrigation and high salinity (to a tolerable extent). On the other hand, water and salinity stresses will have different effects on the performance of the mentioned plants. In this region, olives are used in two forms, canned and oil production. The amount of olive oil is often dependent on the growing conditions and fruit ripeness, and how the oil accumulates. The amount of oil in the dry matter of the fruit during the fruit ripening period (second fruit growth period) and its accumulation increases until the onset of dark purple. The quantity and quality of irrigation water affect the time and amount of oil accumulation, as well as the quality of olive oil. Also, the shelf life of olives in canned conditions and the shelf life of the aroma and taste of extra virgin olive oil are important features that will be controlled and examined by studying the density of olives during the fruit growth period. Therefore, the main purpose of this study is to investigate the changes in the density of olives during the fruit growth period under conditions of low irrigation and salinity stress.

The study area is located in the central part of Marvdasht city in Fars province, Iran, at geographical coordinates '693196;3303288' with an elevation of 1620 meters above sea level. According to the De Martonne method, the climate of the region is semi-arid and the dominant wind direction is eastern. Two years (2020-2021) of field experiments were conducted to study olive fruit density in a 20-year-old olive orchard (Roghani variety). The experiment utilized a factorial layout in a randomized complete blocks design with three replications. Five irrigation levels (I1-I5) were tested, ranging from 25% to 125% of olive water requirement. Three saline water levels (S1-S3) were also included, with S1 being saline well water with an electrical conductivity of 3.5-7.5 dS/m, S2 being a combination of 50% well water and fresh water, and S3 being fresh water. The weight and volume characteristics of olive fruits were examined and measured at seven different periods, starting from the fruit's appearance in June until its harvest in December for oil production. The I5S3 represented the control treatment.

Despite the fact that poor quality and quantity of irrigation water (S1, I1, and I2) will result in a decrease in the weight and volume of olive fruit, it is beneficial for improving the quality of suitable oil and will have an impact on the density of olive fruit. Oil production in olive fruit, which occurs during the second period of fruit growth, has a significant role in the density of the fruit. If the volume of fruit does not change (in the case of low-quality and low-quantity irrigation water), due to the increase in oil in a specific volume, it will lead to an increase in fruit weight and consequently an increase in olive density. The increase in density during the first growth period is accompanied by the production of dry matter in the fruit. A decreasing trend in the density of olive fruit can be observed in all irrigation treatments and different salinity levels in both consecutive years. The study found that normal irrigation water (I4 and I5) and appropriate quality (S2 and S3) increase the weight and volume of olive fruit and alter the density of olive fruit. The interaction effect of salinity and irrigation on the density of olive fruit was significant (5%) in both years. In 2020, changes in fruit density during the second period of fruit growth at salinity level (S1) were more pronounced in different irrigation treatments from I2 to I5 compared to other salinity levels (S2 and S3). The highest and lowest density values in 2020 were I2 and I3, respectively. The highest fruit density (1.1356 gr/cm3) was observed in the high salinity level (S1) and low irrigation treatment (I2). In 2021, the highest fruit density (1.1105 gr/cm3) in the first period of growth is related to S1, and in the second period of growth, it decreases compared to S2 and S3. In the same year, I1S3 had the highest value (1.0753 gr/cm3) and I5S3 had the lowest value (0.9899 gr/cm3) in the second stage of olive fruit growth. Although low quality and quantity of irrigation water (S1, I1 and I2) reduces the weight and volume of olive fruit, it is suitable for improving the quality of oil and will affect the density of olive fruit.

This research was conducted with the aim of evaluating the WOFOST for simulating the corn yield and water productivity in two different conditions of water amounts and nitrogen fertilizer supply.In the first research project, the factors of irrigation water amount in four levels and nitrogen fertilizer in four amounts and in the second project, fertilizer in four levels and fertilizer splitting were considered.The results showed that in the first projct, the accuracy of the WOFOST model for simulating water yield and water productivity was in the excellent and medium categories, respectively, while the accuracy of this model in the second project was determined in the excellent category for both aforementioned parameters.The efficiency of the WOFOST model for simulating yield in both project and water productivity in the second one was acceptable, but for simulating water productivity in the first project was in poor conditions.In the first project, changing the nitrogen fertilizer consumption from N1 to N4 caused an increase in the difference between yield in observation and simulation conditions.The amount of irrigation water had no effect on changing the WOFOST accuracy and error.In the second project, increasing the distribution of nitrogen fertilizer from T1 to T2 caused the error of this model to decrease from 6.5 to 3.6 percent.Based on the results, it is necessary to conduct more studies to use the WOFOST model to simulate corn in different amounts of irrigation water, but this model can be used to simulate corn in different amounts and splitting of nitrogen fertilizer.

Currently, about 90 percent of the population of developing countries live in arid and semi-arid areas. Therefore, it is necessary and inevitable to identify the key and effective factors on the growth of agricultural products . The purpose of this research is to evaluate the accuracy and efficiency of the latest version of the AquaCrop model for simulating seed yield, biomass and water productivity efficiency of safflower in the form of a randomized complete block design with one control treatment (Conventional irrigation) and four deficit -irrigation treatments, including (RDI80, RDI60: reduced irrigation adjusted by supplying 80 and 60% of soil moisture deficiency) and (PRD80, PRD60: fixed partial root-zone drying irrigation with supply of 80 and 60% of soil moisture deficiency) and with four repetitions in Khuzestan University of Agriculture and Natural Resources was conducted. In order to evaluate the reliability of the model, some statistical indicator including the average normalized root mean Square error (NRMSE), the Coefficient of Residual Moss (CRM), Coefficient of Determination (CD), maximum error percentage (ME), Wilmot index (d) and the modeling efficiency (EF) was used. The statistical index (NRMSE) was obtained for seed yield (4.14), biological yield (10.16) and water productivity efficiency (4.9) and showed that the accuracy of the model in simulation is excellent. The results of the model validation show the accuracy and efficiency of the model in simulating seed yield, biomass and water productivity efficiency, and therefore, this model can be used to manage safflower irrigation in different states of deficit irrigation.

Water is the most important factor limiting agriculture in the country. For this purpose, the effect of two irrigation methods (basin irrigation and tape irrigation) and three irrigation levels (50, 75 and 100 percent of the plant's water requirement) on the performance of edible onion plants in Aysk city, which has a relatively hot and dry climate, was studied. Was investigated. This research was done factorially in the form of randomized complete block design with four replications in two crop years 2017-2018. The results showed that the yield of onion under the influence of different levels of irrigation, the highest effect is in the yield related to the treatment of 100% water requirement and the lowest related to the treatment of 50% water requirement. Also, in terms of onion water consumption efficiency, it was found that Tape irrigation method with an average of 4.69 kg per cubic meter of water is 45.4% more than the basin method with an average of 2.56 kg per cubic meter of water. Also, the effect of different levels of irrigation on the efficiency of water use in 100% water demand with an average of 4.64 kg per cubic meter of water was not much different from the treatment of 75% water demand with an average of 17.4 kg per cubic meter of water. As a result, tape irrigation with a stress level of 75% of the plant's water requirement is the most appropriate method and irrigation water level for onion plants in this region.

This research was conducted in order to investigate the interaction of different levels of irrigation and nitrogen fertilizer on the yield of Forage Corn in Khorramabad. The experiment was conducted as factorial in a randomized complete block design with three replications. The first factor consisted of four irrigation levels including I125 (125 Percent of water requirement), I100 (100 Percent of water requirement), I75 (75 Percent of water requirement), and I50 (50 Percent of water requirement) and the second factor consisted of three levels of nitrogen fertilizer including N400 (400 Kg/ha), N250 (250 Kg/ha), and N100 (100 Kg/ha). Based on the evaporation pan method, the total irrigation requirement for treatments I125, I100, I75 and I50 during the period were 761, 642, 524 and 406 mm, respectively, which were more than the amount of water requirement reported in the national water requirement document of plants.The result showed that the maximum amount of wet and dry matters, plant height, leaf area index which were 80 and 21.2 tons per hectare, 9595 mm2 and 220 cm, respectively, were obtained in I125N400 treatment, which had a significant increase (5 Percent) compared to the control treatment (I100N250). The minimum amount of these traits which were 30 and 10.64 tons per hectare, 7096.133 mm2 and 100 cm, respectively, were obtained in I50N400 treatment, which had a significant decrease (5 Percent) compared to the control treatment (I100N250). It was found from the results of this research that at the levels of I125 and I100, the values of wet matter and leaf area index were increased as the amount of nitrogen fertilizer increased. At irrigation levels of 75 Percent and 50 Percent of water requirement, increasing the amount of fertilizer did not cause significant changes in the measured traits. In this research, the maximum value of water productivity for wet and dry matters was obtained in I100N400 treatment with values of 10.9 and 2.91 kg/m3, respectively.

Climate change means any specific change in the long-term average weather state that occurs for a given location or for the entire globe (Goudarzi and Koupaei, 2020). Climate change is one of the most critical factors threatening food security, and it is expected to make food and nutrition security more challenging in the future (Carpena et al., 2019). It will affect the agricultural sector by changing the irrigation water requirements, crop yield, and water productivity (Boonwichai et al., 2018; Liu et al., 2019). Rice is the third most important crop in the world, following wheat and maize (Kapela et al., 2020). The occurrence of water shortages and droughts have raised concerns about the sustainability of rice production, including the main rice cultivation production region of Mazandaran in Iran (Yosefian 2018). Most studies have reported that rice production will decrease in the future due to a projected increase in temperature and a projected decrease in precipitation) Basak et al. 2010; Boonwichai et al. 2018; Nasir et al. 2020; Nicolas et al. 2020). Although many farmers, particularly in Iran, feel that permanent flooding conditions for rice farming are inevitable, climate change forces the use of water-saving technologies to ensure the long-term viability of irrigated rice production in paddy fields (Yosefian 2018; Mirfenderski 2022). Accordingly, it is necessary to find new methods for rice cultivation that reduce water use and make optimal use of the available water for irrigation while maintaining yield under climate change. The goal of this study was to examine the water requirement, water productivity, and risk of rice yield for different irrigation levels under various climate change scenarios using a crop simulation model.

Water scarcity is the most important factor limiting the production of agricultural products, especially in arid and semi-arid regions. Application of some materials such as superabsorbent polymers in soil increases water retention in soil and thus reduces water consumption and fertilizer leaching. These materials can reduce the effects of dehydration on the plant and lead to increased yield in arid and semi-arid regions. In order to investigate the effect of superabsorbent under water stress conditions on yield, yield components and some physiological characteristics of corn, experimental plots were conducted in the form of split plots in a randomized complete block design in Gotvand region in Khuzestan province. Three treatments of Aquasorb 3005 (600,300,0 kg / ha) A1, A2 and A3 and four irrigation strategies (50,75,100,125) percent of water requirement I1, I2, I3 and I4 in three replications for two growing seasons, respectively Summer 2019 and spring planting 2020) were considered. Irrigation planning, biological yield, harvest index and canopy cover were measured at different stages of growth seasons, based on which a growth simulation model was presented using AquaCrop software. The results of this test showed that the use of Aquasorb 3005 increased product performance by one percent. In addition, the results show the effect of superabsorbent application and irrigation planning on improving water efficiency. The highest grain yield in spring and summer cultivation was related to I2A3 treatment equal to 9055 and 9255 kg / ha, respectively, and the lowest yield in both crops was related to I4A0 treatment equal to 5977 kg / ha in spring cultivation and 6344 kg / ha in summer cultivation.

Aloe vera L. is one of the medicinal and perennial plants, which is cultivated in arid and semi-arid regions. Although this plant is relatively resistant to lack of irrigation, but in the conditions of commercial cultivation, it is necessary to pay attention to the supply of irrigation water during the growing season. Due to that, the present study was conducted in order to investigate the effect of the amount of irrigation water (I1: 50, I2: 75 and I3: 100% of water requirement) and Trava 2020 superabsorbent (A1: zero, A2: 5 and A3: 10 grams per kilogram soil) on the yield and yield components of Aloe vera. These treatments were applied in three replications and the crop was harvested in two times include: autumn 2020 and spring 20201. The experiment was carried out in a research farm in Omidiye city with longitude 30°37’ and latitude 49°49’. Leaf length, leaf width, leaf weight, number of leaves and number of offset in the second harvest were 26.8%, 25.1%, 25.5%, 27.0%, 24.1% and 17.5% more than the first harvest. Increasing the consumption of superabsorbent caused an increase in leaf length. The difference between the leaf length in two treatments A3 and A2 was about 3.4% and between two treatments A3 and A1 was about 6.9%. With the increase of superabsorbent consumption, the leaf width increased so that its value reached from 79 mm in A1 treatment to 83 mm in A3 treatment.

The purpose of this study was to investigate CropSyst model accuracy in simulating winter Alvand variety of wheat grain yields under different irrigation regimes. In this study, the CropSyst model was calibrated and evaluated for winter Alvand variety of wheat in the Eghlid region, Fars Province, under different irrigation treatments of 50, 75, and 100% of the field capacity. The agreement coefficient and normalized mean square error of calibrated model using Presley-Taylor evapotranspiration (ET) equation were 0.97, 11.4. The performance of the CropSyst was acceptable. Different irrigation regimes resulted in the difference in product performance and the min performance was obtained from the 50 percent regime. The productivity was different every year and the maximum yield was gained from 100% irrigation regime. Simulation error was minimum at 100% regime. Time of maturity was increased from 100 to 75 and 50% regime. Maximum of dry biomass and performance (ton/hectare) was obtained in 100% irrigation regime, and the minimum was obtained from 75% irrigation regime in the third year, so the performance of 50% regime was more than 75% in the third culture year. It could be from the complicated interaction of water, climate, soil, and plant in different years. The CropSyst can be used for winter Alvand wheat production simulation under different irrigation regimes (with no fertilizer deficit and no salinity).

From the economic and medicinal point of view, Aloe vera is a herbaceous and perennial plant that has attracted the attention of many farmers Iran. Climatic conditions throughout the year and the quantity and quality of irrigation water affect Aloe vera yield. For this reason, the research was conducted with the aim of investigating the effect of aforementioned factors on the Aloe vera yield and yield components. To achieve this goal, a strip-block design was carried with two factors, include: amount of irrigation water at three levels (I1: 50, I2: 75 and I3: 100% of irrigation water requirement) and irrigation water salinity at two levels (S1: 5 and S2: 10 dS.m-1) with three replications, in a research farm in Omidiye with longitude 30°37° and latitude 49°49°. The first harvest was done in the fall of 2019 and the second harvest in the spring of 2020. The results showed that in the first harvest, irrigation had a significant effects on leaf width, leaf fresh weight (P-value≤0.05), gel weight, the ratio of gel weight to leaf weight, the number of leaves and the water use efficiency (P- value≤0.01). Salinity had a significant effects on leaf thickness (P-value≤0.05), leaf width, leaf fresh weight, gel weight, the ratio of gel weight to leaf weight and water use efficiency (P-value≤ 0.01). In the second harvest, irrigation had a significant effects on the ratio of gel weight to leaf weight, number of leaves and water use efficiency and salinity had a significant effects on leaf width, leaf thickness, leaf fresh weight, gel weight , the ratio of gel weight to leaf weight and water use efficiency . In both the first and second harvests, the interaction effect of irrigation water and salinity only showed a significant effect on the water use efficiency (P-value ≤ 0.05).

Water and moisture in the soil is one of the main factors in determining area under cultivation and as a result production of agricultural products, which is limited in arid and semi-arid areas such as Iran, this limitation and lack of water resources affects the performance of plants and especially Medicinal plants. Using deficit irrigation methods and promoting the concept of water productivity in the production of agricultural products is a practical and common method in different parts of the world to maintain and optimally use water resources. Water productivity actually expresses the amount of product or income. It is obtained from the water consumption unit. During their growth period, plants may face many environmental stresses that have different effects on their growth and performance based on the sensitivity and growth stage of the plant. Drought stress is one of the most important factors limiting the physiological and nutritional growth of plants. It is always necessary and important to know the combination or combinations that lead to reducing the effects of drought stress in plants. Although the toxicity of selenium in high concentrations is evident on plants and it is considered a type of stress, nevertheless, the beneficial effects of its low concentrations in protecting plants against non-living stresses through almost complex mechanisms have been identified. Nowadays medicinal and aromatic plants have received a lot of attention in various fields, including agriculture and pharmaceutical industries. Peppermint plant is a herbaceous and perennial plant that is considered as a medicinal and aromatic plant and is widely used in the pharmaceutical industry. The main purpose of this research is to compare and investigate the effect of selenium in different situations of its application (Mixing with irrigation water and foliar spraying before and after applying moisture stress) on water productivity and some properties of peppermint plant )Mentha piperita L) was under Drought Stress.
For this purpose and in order to investigate the effects of drought stress and different forms of selenium application on water productivity and some characteristics of Mentha piperita L, an experiment was performed in factorial form and in a completely randomized design and in three replications on Mentha piperita L in the research greenhouse university of Torbat-e Jam. The effects of drought stress include two levels 100 (I1) and 50 (I2) percent of water requirement and the application of selenium includes four levels (no application (zero), I (Mixing with irrigation water at the rate of 5 milligrams per liter of sodium selenate (, Leafbefore (Foliar application of selenium at the rate of 5 milligrams per liter of sodium selenate before applying moisture stress) and Leafafter (Foliar application of selenium at the rate of 5 milligrams per liter of sodium selenate after applying moisture stress) was investigated. In order to properly establish the seedlings, plants were irrigated once every other day for two weeks after the transfer of rhizomes. Then the process of applying the treatments began. In this way, in the treatment of selenium mixing with irrigation water, sodium selenate at the rate of 5 milligrams per liter was mixed with irrigation water and given to the desired pots in each irrigation cycle, and moisture stress treatments were also applied at the same time. Finally, after 5 weeks of selenium treatments and moisture stress, the plant was harvested. Also, in the Leafbefore treatment, the desired pots were treated with sodium selenate (Na2SeO4) with a concentration of 5 milligrams per liter as a foliar spray solution. Foliar spraying was done three times every other day and 24 hours after the last foliar spraying, the desired pots were subjected to moisture stress for 30 days and then the plant was harvested. Also, in the Leafafter treatment, after proper establishment of seedlings, the pots were first subjected to moisture stress, and after 30 days of applying moisture stress, foliar spraying of selenium at the rate of 5 milligrams per liter of sodium selenate three times as It was done every other day and one week after spraying the plant, the plant was harvested. The results of this research showed that with the increase of drought stress level from 100% of water requirement to 50% of water requirement, fresh weight, dry weight, percentage of essential oil, plant height, number of leaves and root fresh weight Mentha piperita L decreased by 34/95%, 33/64%, 34/53%, 29/35%, 34/17% and 33/61% respectively, and water productivity increased by 30/69%. Also, in the selenium treatments including Leafbefore, Leafafter and I, compared to the absence of selenium, water productivity 66/87%, 41/79% and 29/25% respectively increased. Among the selenium treatments, the Leafbefore treatment had the highest increase in fresh weight, dry weight, water productivity, essential oil percentage, plant height and number of leaves, and treatment I had the highest increase in the root fresh weight Mentha piperita L. The results showed that selenium in the concentration used in this research increased some properties of Mentha piperita L and was effective in reducing the effects of drought stress in this plant.

Gradual decline in water resources require suitable management of irrigation water and applying of deficit irrigation.Field tests to analysis of different states of deficit irrigation are constrained due to restriction of the experiment reliability to the physical conditions of the test place and limited number of the testing scenario in field and the high cost of testing.To overcome these limitations, crop models can be used as a powerful tool to simulate field tests.In this research, AquaCrop model was evaluated in deficit irrigation of winter wheat in Zanajn Region.The study data was collected from filed test values which was done in Research Farm of University of Zanjan at2010-2011.The filed test was carried out to assess reaction of winter wheat to deficit irrigation treatments.The test was done as split plot design on the base of complete randomized block.Irrigation treatments were done as supplying of100%,80%and60%of crop water requirement.The first replication data was used for model calibrating.By entering harvest index data of the second and third replications data of irrigation treatment to model.their yield and water use efficiency were simulated.On the result, the highest difference between simulated and recorded data of yield and water use efficiency were as6.9%and7.0%(respectively)at the third replication of 80%crop water requirement treatment.The least difference were as1.0%and0.5%(respectively)at the second replication of60%and80%crop water requirement treatment(respectively).R2of simulated and real data was calculated0.96for yield and0.99for water use efficiency.High value ofR2data was demonstrated suitable performance of AquaCrop model in simulation and forecasting of yield and water use efficiency of winter wheat in deficit irrigation condition.

Irrigation water scarcity is one of the major limiting factors in agricultural production. This study was conducted to investigate the interaction effect of soil textures and irrigation levels on yield, yield components, and water productivity of Garden cress (Lepidium sativum L.) in the experimental research greenhouse at Ferdowsi University of Mashhad, during 2018. In this study we used a factorial experiment based on the completely randomized design with 3 replications. Treatments consisted of 3 levels of irrigation (0.33 FC, 0.66 FC, and FC) and 3 soil textures (silty clay, clay loam, and sandy loam). The result showed that decrease of the water irrigation consumption by 34 and 67% resulted in reduction of leaf numbers by 12 and 13.2%, leaf length (8.2 and 8.5%), leaf width (11.1 and 25%), and shoot dry weights (7.4 and 16.8%). The results showed that the highest of plant height, shoot fresh weights, and yield of garden cress by 16.9 cm, 10 g, and 565.9 g.m-2 were observed in FC+silty clay treatments. The highest of water productivity was observed in 0.33 FC+ silty clay (by 1.15 Kg.m-3). Also, garden cress is sensitive plant under drought stress conditions and the best texture for this plant is silty clay texture.

In recent years, the quinoa plant has been used extensively due to its favorable cultivation conditions in harsh climates. The cultivation of this plant is important given that Iran is located in an arid and semi-arid region. In the present study, the effects of different levels of water stress and nitrogen fertilizer were investigated on the yield and yield components of quinoa cultivar Giza-1. A factorial experiment in a completely randomized design based on potted planting with three replications was conducted in the research greenhouse at the Ferdowsi University of Mashhad in 2019. Periodic water stress factor consisted of four levels (without stress (control), stress in the total growth period, stress during the flowering stage, and stress during grain filling stage) and nitrogen fertilizer factor comprised three levels (0, 50, and 100 kg ha−1). To apply stress in different growth periods, the plants were irrigated at 50% of soil field capacity. The results of mean comparisons indicated that height, the number of offshoots, spike length, spike width, stem diameter, grain yield (GY, 134.8 g), and water use efficiency (WUE, 0.27 kg/m3) were significantly affected by water stress at 1% level and the number of spikes at 5% level. The interaction of water stress and nitrogen fertilizer significantly influenced the number of spikes, stem diameter, and GY at the 1% level and WUE at the 5% level. Overall, the highest GY was observed without stress treatment under irrigation at 450 mm and using 50 kg ha−1 of nitrogen fertilizer. The best yield-water-nitrogen production function is a linear function (Y = -0.835 + 0.034 I + 0.012 N) that can be fitted on quinoa cultivar Giza-1 based on the applied statistical indices and ranking of functions in the conditions of this study.

in order to determine the economic evaluation of Grain Maize crop behavior in relation to Surge and alternate Deficit irrigation strategy, a research in Jaydar plain of Poldokhtar city during the year 2021-2022 was done. The statistical design of the research was Factorial design in a randomized complete block design Which has two factors at 5 and 3levels. Factor A (five furrow irrigation methods) including conventional irrigation (C), Surge irrigation with one-to-one flow wave cycle ratio until advance time is complete (S_1), Surge irrigation with two-to-one flow wave cycle ratio until advance time is complete (S_2) , fixed alternate irrigation (FF) and variable alternate irrigation (AF) as well as factor B (three irrigation regimes) including 100% water requirement (I_100), 80% water requirement (I_80) and 60% water requirement (I_60). The number of experimental treatments was 15 and the number of replications was 3 replications. The results showed that in irrigation methods, the highest gross and net profit in relation to the amount of water consumed is related to the s_1 surge irrigation method respectively with values of 20.24 and 9.87 thousand Rials per cubic meter. In different irrigation regimes, the highest gross and net profit in relation to the amount of water consumed respectively is related to the (I_80) with the amount of 19.46 thousand Rials per cubic meter and (I_100) with the amount of 8.29 thousand Rials per cubic meter was determined. Finally for different irrigation treatments, the highest gross and net profit in relation to the amount of water used was related to the treatment S_1 I_60 respectively is 22.53 and 10.7 thousand Rials per cubic meter.

Salinity and water scarcity are limiting factors for sustainable agricultural production. The cultivation of resistant plants to environmental stresses is one of the important management factors for sustainable production. The objective of this study was to determine the water requirement and plant response coefficients to water deficit stress (Ky) in different growth stages under the Khuzestan province climate. This study was performed on the quinoa cultivar Titicaca in Ahvaz City in 2019 in a randomized complete block design with 13 treatments and three replications. Treatments include full irrigation and application of three levels of water deficit stress (30, 50, and 70% of allowable soil moisture depletion) at four different stages of plant growth. The duration of the initial, developmental, middle, and late growth stages of quinoa was 24, 28, 32, and 18 days, respectively (total growth period=102 days). The highest quinoa yield was obtained in full irrigation treatment (3700 kg ha-1) with a water requirement of 312 mm. Plant response coefficient to water deficit stress in the initial, developmental, middle, and late stages were 0.8, 0.65, 0.74, and 0.47, respectively. Although quinoa is a drought-resistance plant, it should be noted that the water stress in the two initial and middle stages (quinoa sensitive growth stages to water stress) reduces the quinoa yield significantly that should be considered in the planning of deficit irrigation.