مجله آبیاری و زهکشی ایران
سال شانزدهم شماره 6 (بهمن و اسفند 1401)

In order to simulate rice yield, biomass and water use efficiency using two crop models, AquaCrop and ORYZA, this research was conducted at Khuzistan Agricultrual Research Station. In this study, three types of cultivation (D1: transplanting, D2: current directs seeding consorted seeding, and D3: dry bed seeding) and rice cultivars (V1: Red-Anbori, V2: Champa, V3: Danial) were considered. Results showed that AquaCrop model had acceptable accuracy for simulation of rice yield based on MBE (0.36 ton.ha-1), RMSE (1.07 ton.ha-1) and NRMSE (0.14) values. Above mentioned values for ORYZA were 1.07 ton.ha-1, -0.06 ton.ha-1 and 0.14, respectively. RMSE, MBE and NRMSE values for biomass simulated by AquaCrop were 1.20 ton.ha-1, 0.07 ton.ha-1 and 0.32, respectively. The mentioned values for biomass simulated by ORYZA were 0.69 ton.ha-1, 0.04 ton.ha-1 and -0.22, respectively. NRMSE for biomass simulated by AquaCrop and ORYZA were 0.22 and -0.22, respectively. MBE, RMSE and NRMSE values for water use efficiency simulated by AquaCrop for -0.11 kg.m-3, 0.4 kg.m-3 and 0.15, respectively. Those values for water use efficiencies simulated by ORYZA were -0.03 kg.m-3, 0.4 kg.m-3 and -0.13, respectively. MBE, RMSE and NRMSE values for water use efficiency simulated by AquaCrop were -0.11 kg.m-3, 0.4 kg.m-3 and 0.15, respectively. Those values for water use efficiency simulated by ORYZA were -0.03 kg.m-3, 0.4 kg.m-3 and -0.13, respectively. Regarding the results, it is recommended to use ORYZA model for simulation of rice yield, biomass and water use efficiency.

In this study, the future perspective of evaporation from the free water surface of Shahid Abbaspur dam reservoir was investigated using the multiple linear regression analysis of pan evaporation (MLR-Epan), the micro-scale atmospheric circulation model of LARS-WG6, and HadGEM2-ES model output, under RCPs emission scenarios for three time periods of 2021-2040, 2041-2060, and 2061-2080. The results of the Mann-Kendall test from 2021 to 2080 showed that under the RCP2.6 scenario, the trend of annual changes in the minimum temperature, maximum temperature, and evapotranspiration of the Karun catchment basin was insignificant. However, under RCP4.5 and RCP8.5 emission patterns, the annual trend of the mentioned parameters increased significantly (α = 0.01). The accuracy of MLR-Epan in the base period was confirmed by the results of the hypotheses tests, so that 87% of the changes in evaporation from the pan was explained by the three variables of minimum temperature, maximum temperature, and evapotranspiration. The findings showed that in the coming periods and based on all three radiative forcing patterns, the average annual surface evaporation from the Shahid Abbaspur dam reservoir will increase from 7.2 to 20.2 percent compared to the observation period. In the next sixty-year period (2021-2080) under the RCP2.6 scenario, the annual evaporation from the free water surface will be on the raise, but the increasing trend is not significant. Nevertheless, under RCP4.5 and RCP8.5 scenarios, the increasing trend is estimated to be significance (α = 0.01). Based on Sen's Slope estimator, the amount of evaporation from the reservoir surface is predicted to be 1.4, 19.1, and 31.9 mm, respectively, in the next 60-year period and under the investigated scenarios. Consequently, according to the future climatic conditions, it is necessary to reduce evaporation losses in dam reservoirs with proper planning and informed decisions.

Lack of water resources and rainfall are among the problems facing agriculture in hot and dry regions. The experimental factors included irrigation level (100, 70, and 50% of water requirement) and water type (separate, mixed, and mixed irrigation with treated wastewater and saline well water) in three replicates. Land preparation and cultivation of barley seeds were done in the agricultural lands of Birjand wastewater treatment plant , and after the harvest, the barley seeds were separated and digested, and the concentration of manganese, aluminum and arsenic was measured. The results showed that the concentration of arsenic in barley was insignificant in all treatments and the range of changes of manganese was between 68.4 and 96.5 and aluminum was between 39 and 115.2 mg/kg, which is in accordance with the animal feed standard. In this regard, the concentration of manganese and aluminum in the irrigation treatment was 79.4 and 53.7, respectively, and in the mixed irrigation treatment it was 78.3 and 52.1 mg/kg, and no significant difference was observed between them at the statistical level of 5%. Lack of irrigation in all treatments caused an increase in manganese accumulation and in all treatments except irrigation with treated wastewater and intercropping irrigation caused an increase in aluminum absorption in seeds. By changing the irrigation regime from 50% of water requirement to 100%, the role of water salinity in the accumulation of metals decreased and the role of treated wastewater organic matter increased. The results of this study in terms of the effect of irrigation water level and the punitiveness of one-in-one irrigation and mixing with purified wastewater and salt water in reducing the accumulation of heavy metals in barley grain, as two low-cost management solutions, are a good guide in the safe use of these unconventional waters. is in agriculture."

Water use planning for irrigation in arid and semi-arid regions is incredibly imperative. The objective of irrigation operations in these areas is to make favorable humidity conditions for plants. The current study probes the water requirement and plant coefficient of adaptive tree species treated for afforestation and urban green space in the arid region of Robat Karim town. To determine the water requirement of biennial species of Ash, Tehran pine, Tree of heaven, Berry, Black maple, and Black locust, in the period from 1 May to 20 November 2018 for 7 months, in Robat Karim city, soil moisture monitoring daily and on the definite hour was monitored by Soil Moisture Meter tool in the greenhouse. According to the results, among the six studied species, the highest rate of evapotranspiration was related to the Berry (146 mm) in the first decade of July, the Ash (142 mm) in the first decade of July, and the Black maple is in the first decade of July (128.2), respectively. The lowest evapotranspiration rates include the Tehran pine (10.1 mm), the Tree of heaven (11/24 mm), and the black locust (16 mm), respectively, all three belong to the third decade of November. Similarly, the variations trend in plant coefficients was minimal in the initial stage. In the two stages of growth and development and the middle stage, plant coefficient increased along with full foliation and development of stems and aerial parts. The highest plant coefficient for the studied species occurs on average in October, which is about the end of the middle stage. Then, in the final stage, with decreasing photosynthetic activity, aging, and leaf fall (November), the amount of plant coefficient decreases. The quantity of cumulative water requirement of the studied species also shows that the order of cumulative water requirement of the studied

in order to investigate the effect of surge and alternate deficit irrigation on yield and water productivity of grain maize variety SC704, a research was done in Jaydar plain of Poldakhtar city during the 2021-2022. The statistical design of the research was factorial in a randomized complete block which included two factors at 5 and 3levels. Factor A (five furrow irrigation methods) including conventional irrigation (C), surge irrigation with on/off cycle ratios of 1 and o.5 (S_1 and S_2, respectively) until advance time is complete, 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. The results showed that compared to the control treatment (CI_100), the highest and lowest water consumption savings related to irrigation treatments AFI_60 and S_2 I_100 were equal to 50.2 and 9.6%.The highest water use efficiency, the lowest surface runoff losses and the deep penetration of research treatments are related to AFI_60 irrigation treatment respectively with values of 75.7, 22.4 and 1.9% . The highest yield (grain weight and total weight of ears) was related to S_2 I_100 irrigation treatment with values of 6202 and 8064 kg / ha, which increased by 4.97 and 5.13% compared to the control treatment. The highest water productivity for grain weight and total weight of ears was related to S_1 I_60 irrigation treatment respectively equal to 0.75 and 0.95 kg / m3 , which increased by 47 and 41.8% compared to the control treatment and it was suggested as the most appropriate method of maize irrigation in the study area.

In this study, while examining the performance of random forest model and Gaussian process regression, simulating the values of electrical conductivity and total dissolved solids in the western stations of Lake Urmia (Chehriq-Olya, Dizj and Tepik) according to the values of flow discharge and The HCO3 of the river flow has been studied in the period of 1971-2020. According to the RMSE and NSE statistics, the simulation results of EC values in the studied stations showed that the error rate of the RF model is lower than the GPR model and the efficiency of the model is also higher. The error rate of simulating EC values using the RF model in the test phase in Chihriq-Olya, Dizj and Tepik stations is about 356, 36 and 47% less than the GPR model. In general, the results showed that according to the simulated confidence intervals of EC and TDS parameters, the performance of the two investigated models is acceptable, but in the case of TDS values, the behavior of the two investigated models in the two stations of Dizj and Tepik is different.

With the development of technology and the industrialization of human societies, the increase of greenhouse gases, the occurrence of climate changes on the surface of the earth and its harmful effects (floods and droughts) on human life, and resources have been confirmed. There, obtaining information about the possible effect of climate change on meteorological parameters is of particular importance and necessity. In this study, an attempt was made to determine the potential effect of climate change on the meteorological parameters of Shiraz the synoptic station in a comprehensive way by using the evaluation of General Circulation Models (12 models) and downscaling of their output (with the help of Multilayer Perceptron Neural Network method). The evaluation results (based on MSE, RMSE, and R) in the base period (1986-2005) proved the superiority of the CanESM2 and HadGEM2CC models. As a result, under the two RCP4.5 and RCP8.5 scenarios, HadGEM2CC outcomes during 2045-2026 and 2046-2065 showed a decrease in precipitation (11-19 and 21-36%, respectively). Also, it depicted an increase in minimum temperature (0.4-1 and 0.7-2°C), an increase in maximum temperature (0.5-1 and 0.9-1.8°C), and an increase in solar radiation (0.35-0.7 and 0.6-1.1 kWh per m2 per day). The HadGEM2CC showed a decrease in precipitation (7-16 and 16-35 %, respectively), an increase in minimum temperature (0.3-0.9 and 0.7-1.7°C), in maximum temperature (0.4-1.1 and 0.9-1.8°C) and in solar radiation (0.3-0.8 and 0.8-1.3 kWh per m2 per day).

In order to investigate the effect of irrigation volumes under drip irrigation condition on grain yield and morphological parameters of corn cultivars, an experiment was conducted during 2018 and 2019 in Gorgan agricultural research station. The experiment was laid out in a randomized complete block design in form of split plot factorial experiment and replicated three times. Treatments were including three irrigation volumes [Irrigation at %100 (I1), %75 (I2) and %50 field capacity (I3)], as A factor, and varieties (SC704, SC705 and SC706) as B factor. The results of analysis varians showed that; effects of irrigation treatments on yield and yield components was significant at %1 probablity and the difference between Varieties was significant at %1 probablity, but intraction effects of two treatments on yield and yield components was not significant. Investigation of grain yield at irrigation treatment showed, the highest yield of I1 treatment was 7.85 ton ha-1, and reduced by %15.03 and %29.68 respectively when the irrigation interval was reduced by 75% to %50 field capacity. Comparison of grain yield at varieties showed, yield of single cross 706 with 7.03 ton ha-1 was%12.84 and %3.68 higher than single cross 704 and single cross 705 respectively. Interaction effect of irrigation value and variety showed, the most grain production was belong treatment of single cross 706 and irrigation at %100 field capacity. Investigation of WUE of showed, irrigation at %75 field capacity and single cross 706 with WUE of 1.15 kg m-3 grain yield had the most WUE compared to other irrigation treatments and varieties. With dimitation of irrigation, plant height and ear length also decreased.

The decrease in rainfall, the increase in drought and the development of agriculture in recent years have led to an increase in the consumption of underground water and an increasing decline in water levels. In this study, using version 10 of GMS software, the condition of Qazvin Plain aquifer was modeled in two stable states for October 2017 and unstable from October 2017 to September 2018. The sensitivity analysis of the model was performed with respect to the parameters of hydraulic conductivity and specific yield, and these parameters were determined after calibration and validation of the model. The sensitivity analysis of the model with respect to the two mentioned parameters shows that the model is more sensitive to changes in hydraulic conductivity compared to changes in specific yield. The root mean square error in stable and unstable state was 0.84 and 1.06 m, respectively, and the absolute mean error was 0.66 and 0.75 m, respectively, which shows the high accuracy of the model simulation. The average value of hydraulic conductivity in the aquifer area was estimated as 14.06 m/day and specific drainage was 0.064. Then the underground water level in 6 scenarios of changing the irrigation systems (maintaining the existing situation, increasing the irrigation level under pressure, changing the systems to surface, changing the systems to rain, changing the systems to drip and irrigation with 100% efficiency) was simulated. The results showed that assuming that the underground water extraction is constant, in the surface irrigation scenario, the underground water level will be at its highest level with 30% return water and in drip irrigation conditions at its lowest level with 3.6% return water.

Achieving sustainable food security due to climate changes and the ever-increasing need for food requires knowing the production capacity of agricultural products in the region. Paying attention to the development of cultivated area and increasing the yield of agricultural products is an effective step towards realizing the goals of production self-sufficiency. In this regard, the present study investigates the advantage of producing horticultural and agricultural products in Mazandaran province in the crop year of 2017. To achieve this goal, three indexes RCA, RSCA and 2 were used. The results showed that among horticultural products, raspberry has the highest advantage in production in the small grain group with RCA equal to 17.82 and RSCA equal to 0.89 in Ramsar and Tenkabon cities. Also, among the agricultural products, sesame has the highest advantage in production in the group of industrial products with RCA equal to 24.71 and RSCA equal to 0.92 in Faridunknar city. However, the obtained results from the 2index for raspberry equal to 12.46 in Ramsar and Tankabon cities and for sesame equal to 13.67 in Feridunkan city showed that despite having an advantage in the production of these two products, they have a low competitiveness compared to the average production of the province. . Also, the results of the correlation test showed that Mazandaran province is weak in terms of yield advantage and the advantage in production is mostly due to the advantage of cultivated area. As a result, policies in this sector should be directed towards improving the yield of agricultural and horticultural crops.

Current study was carried out as a pot experiment to investigate the effect of different irrigation levels (100% and 70% of crop water requirement) and seed priming with salicylic acid solution (zero, 0.5 and 1 mM) on the yield and water productivity of French lettuce in the greenhouse of Zanjan University Research Farm. The experiment was done from November 2019 to February 2020 as a factorial experiment based on randomized complete blocks design with three replications. The water requirements of the control treatment crops were determined by weight method. Based on the results, means of plant fresh weight, plant head diameter, shoot dimeter, relative water content and water productivity in plants was significantly reduced in plants irrigated as 70% crop water requirement by 46%, 19%, 24%, 8% and 35% (respectively) compared to the control treatment. Seeds priming with 1 and 0.5 mM salicylic acid solution, were significantly increased means of plant fresh weight (respectively 115% and 53%), plant head diameter (respectively 23% and 10%), shoot dimeter (respectively 10% and 6%), chlorophyll content (respectively 60% and 30%), relative leaf water content (respectively 59% and 41%) and water productivity (respectively 23% and 11%) compared to the control treatment (hydropriming with distilled water). The results of the interaction of the experimental treatments showed, the maximum and minimum mean of water productivity were in 100% water requirement-1 mM SA (8.9 kg/m3) and 70% water requirement-hydropriming (2.3 kg/m3). In areas like Zanjan with limited water resources where deficit irrigation should be done to save water, seeds priming is suggested to reduce the effects of drought stress on plants.

This study is conducted with the aim of determining the optimal cultivation pattern based on the concept of virtual water and considering the objectives of minimizing virtual water consumption and maximizing economic profit of the products in Omrani plain of Gonabad as a case study. At first, the optimization problems are defined by defining appropriate objective equations, and limitations based on different constrains such as available water or local and regional policies. Then, by using linear and multi-objective programming in MATLAB software, the appropriate cultivation pattern was determined. Next, using GIS, the optimal crops were allocated to different farmland in the region. Results showed that the best policy was a combination of the two-objective including minimizing virtual water and maximizing economic profits. In this case, the amount of virtual water consumption in the region was reduced by more than 57% which is considerable. Also, even with this consumption of virtual water, the higher economic benefit is achievable if the pattern of cultivation is changed.

This study investigated the effect of hydrostatic pressure on clogging of subsurface clay emitters produced by the Plateau Water and Sustainable Development Institute at the Karaj Agricultural Engineering Research Institute. The Plateau Water and Sustainable Development Institute produces and supplies the mentioned emitters for subsurface irrigation of pistachio trees. It is estimated that each ceramic emitter measures approximately 30 cm in length, has an inner diameter of 1.5 cm, an outer diameter of 2.5 cm, and a wall thickness of 0.5 cm. Three groups of seven emitters were selected and tested consecutively for 42 days to investigate the long-term permeability reduction process. The system was operated at hydrostatic pressures of 0.5, 1 and 2 meters. Based on the results of the study, it was found that the amount of seepage from clay emitters decreased in all hydrostatic pressures over time due to a reduction in the participation of pores in the emitter body in water transfer. After 1000 hours of measuring seepage from clay emitters, it was found that water-soluble solutes accumulated in the porous environment of the earthen body over time and caused clogging over time. Based on the very good correlation between the fitted line and the measured points at hydrostatic pressures of 0.5 meters and 2 meters, all analyses performed in the field of occlusion were based upon the data collected at hydrostatic pressures of 0.5 meters and 2 meters. Clogging values measured after 1000 hours of testing at hydrostatic pressures of 0.5 meters and 2 meters were 38.9 percent and 80.3 percent, respectively, and increased logarithmically. Results demonstrated that the higher the hydrostatic pressure in the system, the higher the clogging of the emitter body when a certain amount of water seeped through it.

Limitation of water resources, lack of irrigation planning and undesirable use of water are the main factors limiting agricultural development and increasing food production in Iran. Plant and mathematical models are suitable tools for improving irrigation management, crop increase and irrigation efficiency to simulate soil moisture estimation and plant irrigation planning. This study was conducted in 2017 with the aim of investigating the ability of AquaCrop model to irrigate and estimate soil moisture in sugarcane cultivation lands located in the south of Khuzestan province. The results of soil moisture simulation and irrigation planning were compared with the values measured in the field by AquaCrop model. Overall, the results showed that the accuracy of the model in estimating irrigation planning is more than the soil moisture estimation. The accuracy of the model was somewhat higher in estimating soil moisture with the measured values at the farm level. So that the mean square tide of error (RMSE), tide mean squares of normalized error (NRMSE), coefficient of determination (R²), compatibility index (d) and residual coefficient (CRM) were 2.12%, 0.08, 0.71, 0.88 and -0.035, respectively. Also, the results of simulation of sugarcane irrigation round in the field showed that four irrigation rounds, which on average were 4800 cubic meters per hectare, were saved compared to the control farms. The yield of this field was 128 tons per hectare and the average yield of control farms was 103.60 tons per hectare. The results showed that AquaCrop model can be used as a suitable method for planning and irrigation management of sugarcane cultivation lands.

The aim of this study was to determine the quinoa water-yield function by applying water deficit stress in different growth stages. This study was performed on quinoa cultivar Titicaca in Ahvaz city in 2019 in a randomized complete block design with 13 treatments and three replications. Treatments including full irrigation and application of three levels of water deficit stress at four different stages of plant growth. The functions of water - quinoa seed yield and water use efficiency were fitted as a quadratic function. The trend of yield increase per water consumption up to 3200 m3 ha-1 was upward. From 3200 to 4000 m3 ha-1 of water consumption, the yield was almost constant and maximum (3650 kg ha-1). The most water use efficiency (1.22 kg m-3) was achieved with water consumption of about 2400 m3 ha-1. From 2400 to 3000 m3 ha-1 of water consumption, the water use efficiency was 1.12 kg m-3. Therefore, more water consumption decreased the water use efficiency. Although water scarcity stress increased the water use efficiency in quinoa cultivation, in order to achieve proper efficiency in deficit irrigation management, in addition to the amount of water consumption, the plant growth stage should also be considered. In the climatic conditions of Khuzestan province, initial and middle stages were the most sensitive growth stages of quinoa to water deficit stress