فهرست مطالب abdullah darzi-naftchali

The increase in the human population and the growth in water consumption on one hand, and the rise in sewage production on the other hand, have led to the expansion of environmental pollution threats. The objectives of the present study include launching a pilot project for the localization of knowledge in the design of artificial wetlands in accordance with the quantitative and qualitative conditions of domestic sewage in Iran (specifically, the dormitory of the University of Agricultural Sciences and Natural Resources in Sari) and investigating the possibility of replacing wetland systems with conventional domestic sewage treatment systems in the country.

This study was conducted at the University of Agricultural Sciences and Natural Resources in Sari, involving the construction of six artificial wetlands, each with a length of 3 meters, width of 2 meters, and a height of 1.5 meters, using reinforced concrete. One of the ponds was excluded from the system due to leakage. Inside the ponds, artificial filters at different depths (1 meter: d1 and 1 meter and 30 centimeters: d2) and plant filters (Phragmites australis: p1 and Arundo donax: p2) were filled and planted. D10 and the coefficient of unifo rmity (CU) of the substrate materials were obtained as 2 millimeters and 3.625, respectively, from the grain size analysis. The hydraulic conductivity and porosity of the substrate were 2.523 cm/s and 39.2%, respectively. The specific surface area (SSA) of the substrate materials was calculated as 1.336 m²/kg (2245 m²/m³ of substrate materials). The effluent from the septic tank of the dormitory's baffled septic tank was injected onto the beds after a settling and dilution stage using a pump. In the initial loading, the beds were submerged below the surface, and a three-day retention time was allowed for the first sampling. Quality parameters of the wastewater, including biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), fecal coliform (FC), and total coliform (TC), were monitored to assess the performance of the treatment system.

Although the injected wastewater was diluted up to 25%, a significant removal efficiency of 51 to 55, 41 to 79, 74 to 89, 70 to 95.3, and 78 to 95 percent was achieved for BOD, COD, TSS, FC, and TC, respectively, in different treatments. Among the treatments, the weakest performance was associated with treatment P1D2, while the best purification performance was observed in treatment P2D1. This indicates the dominance of the physical characteristics of the systems at the beginning of the startup period on the purification performance. However, the initial performance of the treatment system was very promising and the removal of some parameters such as TSS and FC was at the average level of a full-fledged wetland treatment system.

This wastewater treatment technology is recommended for all managers and experts in the country's wastewater industry, especially in rural areas with inexpensive land and a population of fewer than 5000 people. These conditions encompass all towns, universities, military barracks, and military facilities as well.

The intensification of drought and water stress caused by climate change is a major factor in yield and productivity reduction in the agricultural sector in arid and semi-arid environments. Agricultural lands are often sorely affected by water tension caused by scarce and low precipitation. This research evaluated the effect of different amounts of water, vermicompost and hydrogel used to save the soil water content on wheat grain and biomass yield. Hence, an experiment was conducted at the research farm of Kashmar higher education institute to evaluate the effects of different amounts of hydrogel and vermicompost on wheat biomass and grain yield. Experimental treatments were included: four levels of A200</sub> hydrogel (i.e. 0(S0</sub>), 0.1(S1</sub>), 0.2 (S2</sub>) and 0.3 (S3</sub>) wt. %) plus four levels of vermicompost (0(V0</sub>), 7(V1</sub>), 10(V2</sub>) and 15(V3</sub>) tons per hectare) and three levels of irrigation water (60(W1</sub>), 80(W2</sub>) and 100(W3</sub>) percent of wheat water requirement). The experiment was carried out in a randomized completely block design (RCBD) in a factorial arrangement as a pot experiment in 144 pots. The results showed that the highest amount of biomass and grain yield was obtained in S3</sub>V3</sub>W3</sub> treatment amounting of 81.7 and 35 grams per pot, respectively. Also, the lowest biomass and grain yield was achieved in S0</sub>V0</sub>W1</sub> treatment at the rate of 35 and 10.2 gram per pot, respectively. Furthermore, grain and biomass yield were significantly affected (P ≤ 0.05) by different amounts of hydrogel and vermicompost under varying irrigation water levels. However, application of hydrogel and vermicompost compounds was not significant on the wheat yields. Overall, the best economic value for achieving the highest amount of grain yield was observed in (S2</sub>, 0.2%) of A200</sub> hydrogel and (V2</sub>, 10 ton/ha) of Vermicompost. Similarly, the highest amount of biomass was obtained in the (S3</sub>, 0.3%) treatment of A200</sub> hydrogels and 15 ton/ha (V3</sub>) of vermicompost. Based on the results, the application of moisture absorbents can be effective in increasing wheat yield in water deficit conditions in the arid and semi-arid environment.

In recent years, due to the repeated emphasis of the country's development programs on food security and promotion of self-sufficiency in the production of basic agricultural crops, many efforts have been made for agricultural development. Ignoring the sustainability of the environment, as one of the fundamental pillars of the sustainability of agricultural production systems, has put a lot of pressure on the fragile environment and especially on the aquatic ecosystems. One of the important aspects for assessing the sustainability of regional water resources is how to determine the long-term satisfaction of the environmental flow requirements (EFR) of the resources. This research investigates the satisfaction trend of quantitative and qualitative EFR of surface and groundwater resources in the area of Tajan Irrigation and Drainage Network (TIDN) in Mazandaran province.

Hydrological and qualitative EFR of surface water (S.EFR) including Tajan River (T.EFR) and Ab-bandans (A.EFR) and groundwater (G.EFR) was determined for pre (1997- 1984) and post (1998-2019) TIDN periods. Hydrological EFR of Tajan River is calculated using four hydrological methods variable monthly flow (VMF), Tennant, Tasman and Smakhtin. The qualitative EFR of this river is determined based on the three main surface water pollutants in the region, including nitrogen, phosphorus and salinity. The minimum volume of water required to sustainably maintain Ab-bandan ecosystems is considered as A.EFR. Due to the fact that until now no specific method has been provided to determine the EFR of groundwater resources; in this research, by combining hydrologic and qualitative parameters such as the depth of groundwater, salinity and, nitrogen concentrations, the EFR of these resources is determined.

The average river flow before and after the operation of TIDN was 14.53 and 8.36 m3 s-1, respectively. Before TIDN, based on MVF, Smakhtin, Tasman, and Tennant methods, the hydrological EFR of the river satisfied in 79.1, 59.2, 69.1, and 90.1% of cases, respectively. The satisfaction was 53.4, 27.1, 41.4, and 73.3% of cases, respectively, during the TIDN operation. From nitrogen and salinity perspectives, the violation rates of the qualitative EFRs of this river during TIDN operation increased by 11.1 and 9.9%, respectively, compared to the pre-TIDN period. EC has the main role in the deficit of qualitative EFR of the river, followed by nitrogen and phosphorus. The operation of TIDN caused an increase in the depth and nitrogen concentration of the groundwater, resulting in an increase in the unstable area regarding these two parameters during the operation period. Before the construction of TIDN, no part of the region had a hydrological EFR deficiency of more than 353 m3, but after that, about 40.6% of the region experienced higher deficiencies than this value. Also, the area with nitrogen related qualitative EFR deficiency rises from 13.4% in pre-TIDN to 35.6% in post-TIDN.

The development of TIDN increases the violation of quantitative and qualitative EFR of surface and groundwater resources in the region. Considering the limitation of EFR satisfaction after TIDN, especially in low rainfall seasons, it seems necessary to revise the cropping pattern and irrigation method. Otherwise, the continuation of the current trend, through completely disrupting the ecological balance, will make agriculture unsustainable.

Conversion of organic matter of municipal waste into compost and its use in agriculture, in addition to reducing pollution and improving the quality of the environment can be effective in improving soil fertility. In this study, the effect of different amounts of this type of compost on yield components, grain yield, oil percentage, nitrogen use efficiency and green water use efficiency of winter canola was investigated under a randomized complete block design with 6 treatments and 3 replications. The required experiments were conductrd during a canola growing season in a research farm in Sari city in Mazandaran province. Experimental treatments were compost application at the rate of 10 and 25 tons per hectare (C10 and C25), chemical fertilizer consumption at the rate of 500 kg per hectare (F500), two combined treatments at 0.5 tons of compost per hectare with 400 kg of chemical fertilizer per hectare (C0 .5F400) and 0.2 tons of compost per hectare with 400 kg of chemical fertilizer per hectare (C0.2F400) and control treatment (Control). At the end of the growing season, number of plants per square meter, number of pods per plant, number of seeds per pod, 1000-seed weight, grain yield, nitrogen uptake by the plant and canola oil content were measured and analyzed by SAS software. Also, the green water use efficiency and nitrogen use efficiency were calculated. Based on the results of analysis of variance, the treatments significantly affected on the number of lateral branches, number of pods, number of plants and grain yield was significant. The highest number of lateral branches per plant and the highest number of plants were obtained in F500 and C25 treatments, respectively. The number of pods and grain yield in F500 treatment were significantly different from its value in control and C10 treatments. The highest amount of seed oil was related to F500 treatment, which was significantly different from the control treatment. The highest green water use efficiency was related to F500 treatment followed by and C25. The use of 25 tons of compost per hectare increased the water use efficiency by 0.49 kg/m3 compared to the control treatment. Based on the results, municipal waste compost can be a good alternative to chemical fertilizers for winter canola cultivation in paddy lands.

Fertilizer management is one of the most important managements to improve production and also to minimize its harmful effects on the environment. The aim of this study was to investigate the effect of optimal and conventional application of nitrogen (N), phosphorus (P) and potassium (K) on the yield of low-yielding (Deylamani and Hashemi) and high-yielding (Fajr and Shirodi) rice varieties. The experiment was conducted as a split plot in a randomized complete block design three replications at a research farms of Sari University of Agricultural Sciences and Natural Resources in 2019. In the absence of any of N, K and P fertilizers, yield of Shiroodi cultivar was 5458, 8399 and 9926 kg ha-1, respectively, and yield of Fajr cultivar was 4894, 7364 and 8903 kg ha-1, respectively. In low-yield cultivars, in the absence of any of N, K and P fertilizers, yield in Hashemi cultivar was 2969, 5134 and 4925 kg ha-1, respectively, and yield in Deylamani cultivar was 3028, 5408 and 5384 kg ha-1, respectively. Optimal application of N, P and K fertilizers caused a significant increase of 82, 65, 55 and 34% of yield in Shiroodi, Fajr, Hashemi Tarom and local Tarom cultivars, respectively, compared with the current application of these three nutrients. The results showed that a suboptimal application of nitrogen, phosphorus and potassium fertilizers is a main limiting factor for rice production, and improving the amount and split application of these fertilizers simultaneously can increase yield by 59% compared to their current application in the region.

The sustainability of subsurface drainage systems is highly dependent on the sustainability of drainage water receiving ecosystems. In this study, using the concept of life cycle assessment, the effectiveness of different subsurface drainage systems was investigated. Required field data were prepared during two canola growing seasons from a field with three types of conventional subsurface drainage system consisting of 0.9 m depth and 30 m spacing (D0.9L30), 0.65 m depth and 30 m spacing (D0.65L30) and a depth of 0.65 m and a spacing of 15 m (D0.65L15) and a bilevel subsurface drainage system consisting of four drain lines at a spacing of 15 m and with depths of 0.65 and 0.9 m as alternate (Bilevel). Also, a plot without subsurface drain pipe was selected as a Control. After rice harvest, canola was cultivated in the area. During the study period, the consumption of inputs and their losses along with other management and agricultural operations were recorded. The environmental impact analysis of the cropping system was performed using SIMAPRO 9.0 software. Among the input sources, direct emission from the field, urea fertilizer and the use of agricultural machinery had the largest contribution in the environmental impact of canola cropping, respectively. Investigation of the final effects showed that the Bilevel drainage system had a better performance than the Control treatment and other subsurface drainage treatments, so that it reduced the environmental effects by 17.4% compared to Control.

Simultaneous improvement of water and nitrogen use efficiency in paddy fields is necessary to reduce the environmental- related issues. Rice, as one of the most important crop, provides the main food of more than half of the world's population. According to the latest available statistics, in the crop year 1396-97, the rice cultivated area the country was 622991 ha, which mainly belongd to the five provinces of Gilan (35.3%), Mazandaran (34.3%), Khuzestan (10.9%), Golestan (9.9%) and Fars (3.4%). Among different provinces, Mazandaran province is the main producer of rice in the country with the production of 1113715 tons of rice. Additionally, rice is the predominant crop in Mazandaran province.

The required field data of Daylamani rice cultivar were obtained during two rice growing seasons (2011-2012) from one ha consolidated paddy field in Sari, Mazandaran province. Data from 2011 were used for calibration and data from 2012 were used for validation of the CERES-Rice model of DSSAT V4.7.5 software package. By using the validated model, the effect of different scenarios of water and nitrogen fertilizer management on water use efficiency (WUE), economic water use efficiency (EWP), physiological efficiency of nitrogen consumption for grain production (NUEg), harvest index and nitrogen harvest index (NHI) were evaluated. The calibrated model was then applied to evaluate the combined effect of three types of irrigation management including continuous flooding (I1), intermittent irrigation with 5 (I2) and 8 (I3) days irrigation frequency and six N fertilizer management treatments including N1 (50% at planting (P), 25% at tillering (T) and 25% at clustering (C)), N2 (25% at P, 50% at T and 25% C), N3 (25% at P, 25% C and 50% at T), N4 (fertilization at C), N5 (fertilization at T) and N6 (fertilization at P).

The minimum (832 kg/ha) and maximum (3640 kg/ha) grain yield were obtained in I1N6 and I3N5, respectively. The simulations showed that the effect of fertilization time and type of irrigation were not independent of each other. I3N5 resulted in maximum HI (0.39), minimum soil evaporation (173.4 mm), maximum WUE (one kg/m3), maximum EWP (12×104 Rials/m3), minimum nitrate losses (52.47 kg/ha), the highest nitrogen fertilizer uptake (99 kg/ha), maximum NUEg (one) and minimum nitrogen stress (0.05). Also, the maximum NHI (0.37) belonged to the I2N5 treatment.

Based on the results, among the applied managements, according to the components of crop yield, harvest index, water productivity, EWP, NUEg, nitrogen uptake, nitrate leaching and NHI, 8 days irrigation frequency was the best option in terms of irrigation management. Also, the use of I3N5 treatment as a superior combined- treatment under both fertilizer and irrigation management in the present study is recommended in terms of water and N use efficiency in the paddy fields of the province.

Simulation models are suitable tools for predicting the effects of different management scenarios and selecting the most appropriate solutions in agricultural production systems. In this study, after evaluating the efficiency of the DSSAT model, the effect of water table management on rice growth and yield was investigated. The required field experiments were performed under a randomized complete block design with four irrigation treatments and three replications during a rice growing season in a research farm at the Sari Agricultural Sciences and Natural Resources University. Irrigation treatments included conventional or flooding irrigation (control) with water height of 5 cm above the soil surface (I1), water table control at soil level (I2), water table control at 5 cm below soil surface (I3) and water table control at 15 cm below soil surface (I4). During rice growing season and at harvest, leaf area index, shoot weight, plant height, number of tillers, biological yield and grain yield were measured. The data of I1 treatment were used for calibration and the data of other treatments were used for validation of the model. In both calibration and validation processes, the DSSAT model showed a good performance for predicting phenological dates, leaf area index, biological yield and grain yield. In the calibration and validation stages, root mean square error (NRMSE) values were in the range of 0.7-7.6% and 1-7.6%, respectively, and Wilmot agreement index (d) values were in the range of 0.73-0.99 and 0.82-0.99, respectively. Effects of irrigation treatments were significantly different on plant height, number of tillers per hill, leaf area index, grain yield and biological yield. Among different treatments, the highest grain yield was 5584 kg ha-1, related to the control treatment. Grain yield in I2, I3 and I4 treatments was 4.7, 4.6 and 39.2% lower than that in the control treatment, respectively. Water use efficiency in I1, I2, I3 and I4 treatments was 0.48, 0.65, 0.83 and 0.73 kg m-3, respectively. Based on the results, in order to maintain rice production while saving water, it is recommended to control the water table at a depth of 5 cm below the soil surface.

Suitable prediction of climatic parameters is considerably important for adapting to climate change and mitigating vulnerabilities in local scales. In current research, for climate change assessment, the CanESM2 model in the 5th IPCC report and Statistical down scaling model (SDSM) was used under three scenarios: RCP2.6, RCP4.5 and RCP8.5. The input data were minimum and maximum temperature and solar radiation of Gharakheil synoptic station in Ghaemshahr and NCEP data (National Environmental Prediction Center) for the base period (1984-2005). Sunshine hours were converted to solar radiation using adjusted Angstrom formula for climate condition of the north of Iran. Future climate scenarios were then developed for early-future (2011–2040), medium-future (2041-2070) and late-future (2071-2100). The results showed that during these periods, solar radiation, maximum temperature and minimum temperature will increase by 4-9 %, 5-24% and 8-34% compared to the base period. The largest increases (5.30c and 4.20c for maximum and minimum temperatures respectively, and 1.3 Mj/m2 for solar radiation) will occur during late future period under RCP8.5 scenario. Since temperature and radiation are the main affecting factors for crop growth and yield simulation, the planning is essential in order to choose the appropriate planting date to adapt to climate change in the study area

Optimal management of water resources in a plain with land uses requires proper prediction of water resources response using efficient models. In this research, Soil and Water Assessment Tools (SWAT) model was used to simulate surface and groundwater resources in Behshahr - Bandar-e-Gaz Plain. After analysis the sensitivity, calibration and validation of the model was performed based on river flow data of 2007- 2013 and 2014- 2017, respectively. Groundwater table simulation was done by simulating the recharge rate per hydrological response unit (HRU). The results of sensitivity analysis showed that the parameters GW_REVAP, GW_DELAY, SHALLST, DEEPST, RCHRG_ DP, ALPHA_BF, SOL_AWC, CN, HRU_SLP, ESCO, USLE_P, OV_N, FILTERW and EPCO were the most sensitive parameters. In order to evaluate of the model, the performance criteria of Nash- Sutcliffe (NS) and Correlation coefficient (R2) were used. In the calibration stage, these coefficients ranged from 0.56 to 0.93 and 0.74 to 1.00, respectively, and in the validation process were in the range of 0.56 to 0.84 and 0.66 to 0.92, respectively, indicating the acceptable accuracy of the model in river flow simulation. Comparing the observed and simulated water table depths, NS (0.81) and R2 (0.91) coefficients indicated the capability of the model to simulate groundwater level. According to the results of the water balance analysis, the most of the total water input to the plain, it’s 60% was used for evapotranspiration and it’s small parts as 18% and 22% allocetaed to surface runoff and infiltration, respectively.

Due to the increasing environmental and economic costs associated with nitrogen (N) consumption, improving N use efficiency in rice cultivation systems is of great importance. In this regard, the combined effect of different surface and subsurface drainage systems and water management on the nitrogen harvest index (NHI) of rice was investigated. During three rice growing seasons (2014 to 2016), two rice varieties of Tarom Hashemi and Tarom Daylmani were cultivated under alternate wetting and drying in paddy fields with surface and subsurface drainage systems. At harvest, grain yield and biomass and plant and seed nitrogen were measured. The NHI was determined as the ratio of grain nitrogen to nitrogen absorbed by aboveground part of plant. The amount of NHI was directly related to the amount of urea fertilizer used, varying between 58.31 and 68.45 in different seasons. The average nitrogen absorbed by the Hashemi and Daylmani plants in the subsurface drainage systems was 161.7 and 155.7 kg ha-1, respectively, and in the control was 144.7 and 193.7 kg ha-1, respectively. Also, the average grain yield, grain nitrogen, harvest index and NHI in the subsurface drainage systems were 5329.3 kg ha-1, 105.9 kg ha-1, 37.8% and 67.2%, respectively, and in the control treatment was 4667.7 kg ha-1, 88.6 kg ha-1, 32.4% and 56.3%, respectively. Based on the results, drainage through subsurface drainage systems under intermittent irrigation and drainage management can improve the N use efficiency in rice cropping system

In this research, which was carried out in the 4.5-ha consolidated paddy fields of Sari Agricultural Sciences and Natural Resources University during two cropping cycles of 2015-2016 and 2016-2017, the influence of different drainage systems on total nitrate loss into local surface water resources was investigated. These systems included three regular subsurface drainage systems with different drain depths and spacings of, respectively, 0.9 m and 30 m (D0.90L30), 0.65 m and 30 m (D0.65L30), and 0.65 m and 15 m (D0.65L15), and a bilevel drainage system consisting of four drain lines with 15 m spacing and 0.65 and 0.9 m alternative depth (Bilevel). In addition to daily measuring drainage fluxes, nitrate concentrations in the collected drainage water were also measured every other weeks during the cropping cycles. Daily average drainage discharges under Bilevel, D0.90L30, D0.65L30, and D0.65L15 varied in the ranges of 0-231 cm3 s-1, 0-220 cm3 s-1, 0-227 cm3 s-1 and 0-250 cm3 s-1, respectively. Analyzing precipitation-drainage discharge correlations reveals that the precipitation intensity of 10 mm d-1 is the threshold of drainage capacity reduction, and precipitation intensities beyond this threshold may result in water logging challenges in the study area. Consolidating the selected drainage systems may result in annual nitrate losses of 2.2-34.7 kg ha-1 into the surface water resources; however, the D0.65L30 systems may have less environmental consequences in this view of point. Therefore, environmentally sustainable operations of these systems for expanding rainfed-cropping requires precious investigations when selecting drain depths and spacings.

In Mazandaran Province the performance of different drainage systems is essential for Canola cultivation as a second crop in paddies. For this purpose an experiment was conducted in Sari agricultural Sciences and Natural Resources University as base, in 2017-2018 cropping season. In different canola growth stage intervals, eight sampling were established under randomized complete block design with three replications in subsurface drainage systems and surface (Control) in order to determinate leaf area (LA), leaf area index (LAI), numbers of leaves (SLN) and leaf dry weight (LDW). Then Statistical analysis was carried for study of drainage depth and space on the mentioned growth index and mathematical relationship between leaf area and its dry weight with the evaluation of linear and nonlinear regression models was determined in different drainage systems. Maximum of LA in all treatments occurred about 90 day after planting. Mathematical relations between LA and LDW were described by linear and power model is suitable as a correlation coefficient was 0.98. Among the mathematical functions, reverse polynomial functions with degrees 4 and 5, logarithmic equations and inverse logarithmic equations with degrees 3, 4, and 5 showed better results than other mathematical functions The relations obtained in this experiment can be used in simulation models of winter canola growth under water table control conditions.

Proper water management in agricultural fields is largely depends on suitable estimation of evapotranspiration (ET), as a major component of hydrological cycle. The FAO-Penman- montieth method has the ability to provide appropriate estimation of ET, however, due its complexity, using simpler methods is preferred for programming and modeling processes. In this study, using the weather data of the Dasht-e- Naz station in Sari, the capability of 14 methods for estimation daily, monthly and seasonal reference ET was evaluated. These methods included three temperature- based methods, four radiation- based methods, three pan evaporation- based methods and four combined methods. The performance of each method was assessed using statistics including coefficient of determination (R2), root mean square error (RMSE), percent error (PE) and Mean Absolute Deviation (MAD). Investigations showed that the radiation- based equations were more appropriate for estimating ET than other methods. The Irmak (with R2=0.87 and RMSE=5.77 mm d-1) and Ritchi (with R2=0.93 and RMSE=12.59 mm d-1) methods were the best methods with the highest accuracy in the autumn and winter seasons. In the spring, the use of the FAO-24 Pen (with an average error of 0.5 mm) and Rohwer (with an average error of 6.8 mm) (equations are recommended for spring and summer. Based on the results, the Irmak, FAO-24-Radiation, Ritchie, Priestley-Taylor and Blaney-Cridlle methods were five best methods in the study area.

The accurate determination of river flow in watersheds without sufficient data is one of the major challenges in hydrology. In this regard, given the diversity of existing hydrological models, selection of an appropriate model requires evaluation of the performance of the hydrological models in each region. The objective of this study was to compare the performance of artificial neural network (ANN) and IHACRES integrated model to predict the flow of sivand river in Tashak Bakhtegan watershed located in Fars province as a warm and arid area. Calibration and validation procedures were done by using data from 1982-1995 and 1996- 2012, respectively. Neural Network Toolbox of MATLAB software were used to evaluate the capabilities of neural networks. In both calibration and validation periods, simulated flows by the IHACRES model for flood flows, were less than the observed data. The determination coefficients of the model during calibration and validation were 0.62 and 0.54, respectively. The determination coefficients of dynamic neural networks and static neural networks during calibration and validation ranged from 0.88- 0.94 and 0.51- 0.69, respectively. The results demonstrated that artificial neural networks predicted monthly flow of sivand river more accurately than the IHACRES model.

Sustainable development of agriculture is facing with several challenges such as climate change resulting change in the pattern of weather parameters as well as crop water requirements. In this research, due to the important role of agricultural activities whitin Urmia Lake Basin in the production of various agricultural products such as wheat, the possibility of supplying the plant's water requirement from green water and drought and evapotranspiration (ET) changes under climate change were investigated. Using the SDSM model and baseline meteorological data (1967-2015) of Tabriz and Urmia stations, meteorological data for the future period (2016-2100) was projected under RCP2.6 and RCP8.5 scenarios. Reference ET and the severity of drought were assessed by using the FAO-Penman-Monteith equation and the SPI drought index, respectively. The SDSM model had a relatively good performance and accuracy in estimating rainfall and ET in the study area. The findings of the study indicated an increase of 63 and 3% in the average rainfall of the future period for Tabriz and Urmia stations, respectively, and a reduction in severity of drought compared with baseline period. Under climate change, the average of annual ET of Tabriz and Urmia stationswill be decreased by 3 and 1.5%, respectively, and the amount of green water will be increased.

In order to evaluate the effect of different amounts of natural and artificial soil modifiers on biological yield and grain yield of wheat, an experiment was conducted at the research farm of Kashmar high education institute. In this research, experimental treatments were included: four levels of A200 hydrogel (0(V0), 1(V1), 2 (V2) and 3 (V3) grams per kilogram of soil), four levels of vermicompost (0(V0), 2 (V1), 3 (V2) and 4 (V3) grams per kilogram of soil) and three levels of irrigation (40 (W1), 20 (W2) and 0 (W3) percentage of moisture loss). The experiment was carried out in a randomized completely block design in a factorial arrangement in a pot experiment in 144 pots. The results showed that the highest amount of biomass and grain yield in S3V3W3 treatment were 81.7 and 35 gram in the pot respectively, and the lowest biomass and grain yield were in S0V0W1 treatment of 35 and 10.2 gram in the pot respectively obtained. Application of A200 hydrogel and vermicompost had increased biological yield by 31.88% and 18.5% and grain yield by 23.5% and 20.25%, respectively. Under the conditions of this experiment, the interaction effect of A200 hydrogel and vermicompost compounds was not significant. The effect of A200 hydrogel and vermicompost on the grain yield was significant, as the highest value of grain yield was obtained in the treatment of 2 g/kg A200 hydrogel and 3 g/kg vermicompost and the highest value of biological yield was obtained in the treatment of 3 g/kg A200 hydrogel and 4 g/kg vermicompost. Separately use of A200 hydrogel and vermicompost is recommended for achieving maximum biological yield and grian yield.

Due to recent droughts and excessive extraction of groundwater resources, water table of Qom aquifer has had sharp drop resulted in intrusion of saline water into the groundwater and land subsidence. In order to prevent the crisis, operation management of water resources should be a principle in country planning. Simulation models are suitable tools for management and qualitative and quantitative conservation of groundwater resources. In this study, a two-year period data (September 2003- September 2005) were used for evaluating MODFLOW model to simulate the aquifer water table. The model showed the most sensitivity to specific yield, hydraulic conductivity, recharge and discharge, respectively. The correlation coefficient and root mean square error in the calibration stage varied from 0.24 to 0.99 and 0.01 to 0.14 m, respectively. The correlation coefficients and root mean square error in the verification step change between 0.52 to 0.97 and 0.002 to 1.14, respectively. To assess the aquifer response to various stresses, six management scenarios (continued current extraction of groundwater and recharge to groundwater resources, decrease by 10, 20 and 30% and reducing step by step of groundwater extraction, continued current extraction of groundwater and artificial recharge of groundwater using urban wastewater) were defined up to 2020. Based on the model results, the best scenario for restoring and balancing the groundwater is artificial recharge scenario using wastewater up to 2020.

In this research¡ the effect of alternate irrigation and drainage on yield and the change trend of plant height and tiller number of Hashemi rice cultivar was investigated in subsurface- drained paddy fields. The experiments were done under a randomized complete block design with four subsurface drainage treatments and a conventional surface drainage treatment (control). During rice growing season¡ the treatments were subjected to two drainage periods of 10 and 5 days (26 and 43 days after transplanting) as midseason drainage and one drainage period as endseason drainage (63 days after transplanting until harvest). Alternate irrigation and drainage increased tiller number and decreased plant height in subsurface drainage treatments compared with control¡ 2-3 tiller and 1-6 cm¡ respectively. Subsurface drainage resulted in 10- 38 % and 21- 40 % more grain yield and harvest index¡ respectively¡ than control. Based on the results¡ alternate irrigation and drainage will increase the productivity of subsurface- drained paddy fields.

Reservoirs as traditional structures in water resources management system in MAZANDARAN province play a major role in supplying irrigation water for paddy fields. Dredging and improvement of such structures can result in getting more benefits from the surface runoff. In current research¡ using satellite images and ArcGIS software¡ land use over the case study area of GATAB¡ BABOL¡ Iran¡ was determined. Then the potential of the surface runoff in the area was estimated by SCS method. Also¡ irrigation costs for paddies¡ irrigated by groundwater well (four groundwater wells) and reservoir water (four Reservoirs)¡ were estimated. The effect of dredging and improvement of reservoirs on the reduction of groundwater withdrawal and irrigation costs were evaluated. The potential of runoff in the area was estimated to be 31 MCM (million cubic meters). Dredging of all Reservoirs by 1 to 2 meters would result in the exploitation of 1.68 to 3.37 MCM from the surface runoff. A fall in irrigation cost¡ estimated to be 991 to 1982 million Rials per Hectare¡ is a consequent of more proper utilization of surface runoff. According to the results¡ the increase in the storage capacity of reservoirs will result in saving part of groundwater storage in the case study area.

Due to newly-installation of drainage systems in the northern Iran paddy fields and special conditions of soils in these areas, performance evaluation of different drainage envelopes has a great importance. In this study, effect of two types of drain envelopes (mineral and geotextile) on the quantity and quality of drainage water of subsurface drains and water table depth was studied in the consolidated paddy fields of Sari Agricultural Sciences and Natural Resources University. During four successive growing successive seasons of rice and canola, from July 2011 to May 2013, discharge and water table depth in midway between of drain lines and the concentration of EC, pH, Na and Cl of drainage water were measured. Average of drain discharge volume with mineral and geotextile envelopes per day was 2381 lit and 2961 lit, respectively. Comparison of amounts of SEW30 (Sum of Excessive Water) in two growing canola seasons showed that geotextile envelope was more effective in lowering of water table depth than mineral envelope. Also, the minimum and maximum of EC were 1280 and 2190 for drains with mineral envelope and 1190 μs/m and 2026 μs/m for drains with geotextile envelope, respectively. Assessment of amounts of SEI (Salt Export Indicator) of soil showed the leaching during growing seasons. According to the results, geotextile envelope was more effective than mineral envelope in draining surplus water and controlling water table in the study area.

The spatial and temporal variation of wheat virtual water، as one of the strategic product in Sistan and Blouchestan Province، has been investigated. To this end، the 12 year weather data، yield، cultivated area and irrigation method were used. The 12 year average of the net wheat water use was 303 million cube meter from which 9. 2 percentage was supplied by green water. Regardless of the irrigation efficiency، the net virtual water varied among 1. 59 (Khash City) to 6. 18 (Zabol City) meter cube per kilogram and its 12-year average was 3. 42 meter cube per kilogram in the whole province. Considering the real water volume allocated to the wheat، the 12-year average of the imported and exported virtual water in the entire province was 1043 and 43. 2 million cube meter، respectively، and Zahedan and Zehak were، respectively، the biggest importer and exporter of the virtual water. Results showed that decreasing the water loss by 10 percentages through improving irrigation efficiency would increase the sel-sufficiency in whaet production by 18. 2% and decrease the dependency to virtual water import by 3. 62 percentages due to 11. 7 percentage decrease in wheat water use.