مجله پژوهش آب در کشاورزی
سال سی و هفتم شماره 1 (بهار 1402)

This research aimed to simulate the yield of maize cv. S. C 704 under conditions of separate application of salinity stress at different growth stages in mini-lysimeter, in Qazvin area, Iran. The experiment was performed as factorial and in a completely randomized design. Soil salinity treatments, as the main factor, included four levels of 1.7(S1), 3(S2), 5(S3) and 7(S4) dS.m-1. The sub-factors included different growth stages as follows: one-stage at 6-leaves (C1), flowering (C2), and milk stage (C3); and two-stages of C1C2, C1C3 and C2C3. By combining saline water (from a salt marsh) with a well fresh water (0.5 dS.m-1), saline water was prepared according to the treatments. Irrigation was done in a way that the salinity of input and output water from the mini-lysimeters was equal. The control treatment was irrigated with fresh water. By combining the water uptake reduction functions, the derived models were presented and evaluated for simulating yield reduction coefficient (α). The stress application data in one and two-growth stages were used for models calibration and validation, respectively. Applying the highest salinity level led to decrease in dry matter yield from 157.2 g. plant-1 (in S1 treatment) to 115.9, 53.2, 77.7, 86.1, 97 and 46.5 g. plant-1 in the C1, C2, C3, C1C2, C1C3 and C2C3 treatments, respectively. The results showed that crop sensitivity was different in one-stage and two-stage stress application. Salinity stress at flowering (C2) and milk stage (C3) had a more negative effect relative to C1C2 and C1C3. In this research, Van Genuchten's additive model and Dirksen-Maas-Hoffman's multipliable model could be recommended as the optimal models for crop yield simulation. Also, application of two-stage salinity stress (up to level of 7 dS.m-1) in C1C2 and C1C3, had higher yield relative to application of one-stage stress in C2 and C3 growth stages.

The effects of pressure changes and type of emitter on the performance of pistachio orchard’s drip irrigation systems were studied in 21 orchards, under irrigation by saline water. Based on the results, water distribution uniformity in different parts of the orchards (EU) and the average flow of emitters ranged from 71% to 95% and 5.5 to 28.8 l hr-1, respectively. Furthermore, the lowest and highest operating pressure of the emitter were 0.1 and 1.8 bar in different pistachio orchards, respectively. The highest (21%) and lowest (3%) values of coefficient of variation (CV) were obtained from the evaluation of orchards number 13 and 4, respectively. Moreover, the minimum (0.6 %) and maximum (26.2 %) deviation values of the measured average flow from the nominal flow were also observed in orchards No. 3 and 18, respectively. The values of CV in orchards No. 3, 4, 10, 11. 12, 19, and 20 were lower than 10% and were excellent. Orchards No. 2, 13, 14, and 15 with values of about 20% showed good and very good CV, and all of the remaining orchards had very good values of CVs between 10% and 20 %. The results showed that the emitters had a low CV and high EU in the orchards with proper supply and distribution of operation pressure (0.5 to 4 bar) without considering their types and brands. However, the two 8 liters per hour emitters including the Eurodrip and Europlast (King model) for soils with low infiltration rate, and the 26.2 liters/hour Eurodrip emitter for supplying high flow rates with an operating pressure of 0.5 to 1 bar can be recommended. Results indicated that, in most orchards, it is vital to modify the irrigation planning (time and frequency). It seems that if the operating pressure is supplied and distributed properly, emitter clogging and, consequently, EU would not be much affected by water salinity.

This study aimed to determine the response of licorice (Glycyrrhiza glabra L.) to different methods of planting and different levels of water salinity. The experiment was conducted as factorial based on a completely randomized design with 3 replications, during 2019-2020 in Salinity Research Center, Yazd, Iran. Treatments included five levels of water salinity ( 0.9 [control], 3, 6, 9 and 12 dS/m), and two planting methods (transplanting and direct seeding). Morphological traits such as plant height, number of lateral branches, leaf area, total dry weight, and physiological traits such as total chlorophyll and carotenoids, and sodium and potassium contents were measured. The results showed that the highest plant height (62 cm) was in the control (0.9 dS/m) and transplanting method, maximum number of lateral branches (70 per plant) and largest leaf area (1032 cm2) were obtained in the control treatment, maximum total dry weight (2.68 g/plant) was in control and transplanting method, and the maximum carotenoids content (5.5 mg/gFW) was in the control and transplanting.  In the control and direct seeding treatment, maximum  total chlorophyll content (51.21 mg/g FW) and the highest amount of potassium (14.8 mg/kg DW) were observed.  The maximum sodium content (15.2 mg/kg DW) was obtained in 12 dS/m and transplanting treatment. In general, with increasing salinity level to 12 dS/m, plant height in both planting methods decreased. Also, with increase in water salinity,  the number of lateral branches and leaf area decreased by 84% and 88.5%, respectively. Total chlorophyll, carotenoids, and potassium also decreased significantly, but the amount of sodium ion increased. Transplanting was less affected by salinity in most parameters, except the total chlorophyll and sodium. Higher salinity stress had negative effect on different licorice plant parameters including plant height, number of lateral branches, leaf area, as well as the amount of total chlorophyll and carotenoids. In general, transplanting was more productive than direct seeding. The findings of this study show that, in situations with scarcity in fresh water, seedlings should be watered with fresh water, and saline water should be used for irrigation after transplanting.

The current study aimed to identify and analyze the factors influencing acceptance or rejection of irrigation system in apple orchards of Urmia city, as the center of apple production in West Azerbaijan Province, by applying survey research method and Rogers' Diffusion of Innovations Model. Based on the results, 57% of the respondents believed that implementation of drip irrigation using a common source of water (well) had many problems, 63% of them also considered the system unsuitable for old orchards. About 64% of the respondents believed that, in current situation, the relative profitability of the system was in the range of medium to low. 77% believed that drip irrigation systems did not have high performance due to various reasons. According to 81.5% of the respondent’s opinion, applicability of these systems is complex compared to traditional methods, because of design, performance, employment, and administrative bureaucracy, obtaining facilities, repair and maintenance. According to the Cox-Nell and Nagelkerke statistics, the variables included in the model are able to explain, respectively, 0.50 and 0.68 of the variance of the drip irrigation acceptance variable. According to the obtained results, the most important recommendations applicable in the region, are using successful models and reference groups to provide practical trainings on irrigation systems, increasing the relative benefit and reducing the risk of investing in drip irrigation, reviewing the process of designing, implementing, the workflow and the quality of equipment in drip irrigation systems, solving problems related to issuing the necessary permits for orchards that do not have ownership documents and, finally, avoiding the use of drip irrigation in old traditional orchards.

To evaluate the changes in essential oil and chemical compounds of ginger plant under the influence of irrigation interval and NPK macronutrients, an experiment was carried out using randomized complete blocks in the form of a split plot with 9 treatments and 3 replications in Pakdasht Region, in 2021. Treatments included irrigation internals at three levels: V1=4, V2=6, and V3=8 days, as the main factor, and NPK at three levels, F1= (N: 300, P: 100, K: 200), F2= (350, 150, 250), F3 :( 250, 50, 150) (kg.ha-1) as the sub-factor. Extraction of essential oil in this research was done by distillation with water using a Cloninger machine, and the analysis of essential oil compounds was done by gas chromatograph, and 34 chemical compounds were identified. The main components of essential oil in terms of percentage included (α-zingiberene=23.65), (geranial=11.09), (camphene=9.58), (β-sesquiphellandrene =8.43), (β-bisabolene=3.75) and (α-curcumene=2.6). These 6 compounds included 59.1% of the total ginger essential oil, and the other 28 compounds made up only 40.9% of the total essential oil. The results of analysis of variance showed that the interaction effect of irrigation and studied fertilizers on essential oil and main compounds of ginger essential oil were significant at the 1% probability level. The best treatments for essential oil and camphene traits were V1F3, geranial V3F2, α-zingiberene V1F2, and for three traits of α-curcumene, β-bisabolene, and β-sesquiphellandrene was V3F3. Some of the compounds in ginger essential oil were increased by optimal irrigation and supply of essential nutrients for the plant, but some compounds increased under water stress and insufficiency of NPK.

Soil moisture is one of the most important parameters in water, soil and plant resources management. Therefore, the present study was conducted to evaluate the efficiency of thermal and optical remote sensing data in order to estimate soil moisture and irrigation planning in sugarcane fields of Khuzestan Province, Iran. For this purpose, soil moisture content for 9 passes of Landsat 8 and Sentinel 2 satellites was calculated using thermal and optical trapezoidal methods from April to October 2020 in Amirkabir Sugarcane Agro-industry fields. To validate the results, the measured soil moisture content data of 337 ground control points located in 18 sugarcane-growing fields measured by TDR350 dehumidifier were used simultaneously with the passage of the satellites. The results showed that TOTRAM model with a determination coefficient of 0.82 and error rate of RMSE and NRMSE as 4.45% and 12.9%, and OPTRAM model with an explanation coefficient of 0.93 and RMSE and NRMSE error of 3.14% and 12.1% were able to properly estimate soil surface moisture in sugarcane fields. Also, the results of evaluation of soil moisture maps for irrigation planning of sugarcane fields showed that these data could be used for irrigation planning with average NRMSE error of 16% and 9% in relation to ground irrigation time data for TOTRAM and OPTRAM models, respectively. In this regard, OPTRAM model data were more efficient compared to thermal data, due to better spatial resolution of optical data and less effect by environmental factors such as temperature and relative humidity of air and also the effect of adjacent pixels.

Due to the drought, water and food security in the country is facing serious challenges, and a precise and science-based implementation plan is needed. The use of new technologies, such as modern irrigation systems, is essential as an effective tool for optimal water use. Therefore, this study was conducted to investigate the yield, yield components, and water efficiency of rice variety "Honda" in two surface and subsurface drip irrigation systems in a paddy field located in Kiasar, Mazandaran Province, Iran, during the spring and summer of 2022. The experimental design was strip plots using a randomized complete block design with 6 treatments and 3 replications in 18 plots measuring 2 by 3 m. The treatments included surface drip irrigation with strip distances of 25, 50, and 75 cm, and subsurface drip irrigation at a depth of 30 cm with the same strip distances. The results showed that cluster length, number of grains, plant height, and root length were significantly increased in surface drip irrigation treatments compared to subsurface treatments, with an increase of 1.2 cm (6.8%), 8.19 (49.8%), 6.9 cm (8.2%), and 1 centimeters (6.9%), respectively. The grain yield, harvest index, physical efficiency, and economic efficiency in the surface drip irrigation treatments showed significant increases of 1664 kg/ha (40.8%), 4.7% (14.1%), 0.27 kg/m3 (38.5%), and 242,363 Rials/m3 (38.4%), respectively, compared to subsurface drip irrigation treatments. The maximum grain yield and harvest index were observed at distances of 25 cm, equal to 5834 kg/ha and 40%, respectively. The maximum physical efficiency was observed at a distance of 50 cm, equal to 0.93 kg/m3. With an increase in distance between the strips from 25 to 50 cm, the physical efficiency increased by 22%. However, further increase in the distance led to a decrease in physical efficiency. The maximum economic efficiency was observed for surface drip irrigation at a distance of 50 cm, equal to 836,951 Rials/m3.