بهزاد آزادگان

The aim of the research is quantitative modeling of the underground water flow of the plain aquifer and the investigation of management solutions to deal with the drop in the underground water level. This research was investigated using hydrogeological information, hydrology, meteorology and basic studies of underground water sources. Quantitative underground water modeling was done using GMS software and Modflow code and the underground water level was simulated for the years 2011-2015 with 60 monthly time steps. Manual calibration of the model was done for 2011-2014 and its validation was done for 2014-2015. Future management solutions, in the form of combined scenarios:One- 10% reduction in withdrawal from wells with a 5% reduction in feeding from return of agricultural water. Two- 20% reduction in withdrawal from wells with a 10% reduction in feeding from return of agricultural water. Three- Their comparison with the continuation of the existing trend was predicted for the years 2015-2019. The result of the aquifer modeling for the above time periods showed the deficit of the reservoir 33.09 MCM. But by applying a 10% reduction in withdrawal and a 5% reduction in feeding, 21.38 MCM/year and by applying a 20% reduction in recharging from the return flows of agricultural consumption and 10% reduction in feeding, 25.94 MCM/year were added to the volume of the water balance. But with the continuation of the current trend, the deficit volume of the aquifer was estimated to be more than 54 MCM.

Agriculture, especially rainfed agriculture, is one of the branches that is largely affected by the effects of climate change. The previous studies regarding the estimation of the length of the dry season wheat growth period in the country are mainly related to the length of the growth period of the past years or based on the growing degree day method, which is not very realistic. The purpose of this research is to estimate the length of the average growth period of rainfed wheat for the Tabriz Plain for the past 20 years (1993-2017) and the future conditions under the simulation of GCM models, for the next 50 years (1394-1444), using the meteorological parameters of temperature and rainfall. is. In the first step, the state of future conditions was evaluated under the GCM models of the sixth report of the Intergovernmental Panel on Climate Change (IPCC) and under the SSP1-2.6 and SSP5-8.6 scenarios, and then with the proposed method of the ecological zoning guidelines of the Food and Agriculture Organization of the United Nations (FAO), the length of the growth period of each period has been estimated and compared with each other. According to the FAO method, the length of the growth period is equivalent to the period of time when the rainfall is more than 50 percent of the potential evaporation and transpiration. It has been done. The results of comparing the length of the growth period of the base period and the state of future conditions under the simulation of GCM models showed that in the Tabriz Plain, the length of the wheat growth period has increased by an average of 16 days for the next 50 years, and the end of the growth period by an average of It will happen 12 days later.

This study aimed to evaluate the environmental and economic effects of the development of mini-bubbler pressurized irrigation projects as a modern irrigation system in Birjand County, South Khorasan Province, from the perspective of farmers and users, so the quantitative and qualitative processes of these irrigation projects can be evaluated. Data collection was conducted with a survey technique and the results showed that most of the farmers had a favorable assessment of the environmental and economic effects of the plan. The economic factor was found to be the most important factor during the evaluations, which included the variables of reducing the time required for irrigation, increasing the amount of production per hectare, increasing the cultivated area, reducing labor costs, reducing water and irrigation costs, improving the quality of products, and increasing the income from agriculture, which explained ca. 26.2 percent of the total variance. The second factor was the environmental factor, which includes the variables of the more appropriate use of fertilizers and pesticides, reduction of plant diseases, reduction of weeds, and prevention of soil salinization, which explains 21.6 percent of the total variance. Also, the effects of mini-bubbler irrigation on agricultural inputs were also evaluated, which included the variables of less water consumption, less seed consumption per hectare, compliance with the cultivation pattern, and increasing the mechanization factor, and explained 17.8 percent of the total variance. The social factor also includes the variables of gaining social credit, the cooperation of users in maintaining the system, and observing the irrigation schedule, and it explains 11.2 percent of the total variance. Finally, based on the obtained results, suggestions have been made for the success of implementing and using such projects.

With the aim of increasing water, food and energy productivity, this study was carried out in two stages to develop and validate a tool for evaluating agricultural management strategies in relation to the link between water, food and energy security (NEXUS). In the first part, using the WA+ water accounting framework, with the aim of analyzing the parameters of hydro climatology, the four worksheets of basic resources, evaporation and transpiration, harvesting of water resources and productivity of the Plasjan watershed were calculated and management scenarios were determined to increase productivity, and in the second part, management scenarios with The NEXUS approach were evaluated and prioritized. The results of WA+ showed that in the Plasjan basin, the high volume of evaporation and transpiration was useless. In the second part of this research, among the 4 main scenarios (48 sub-scenarios) introduced to improve productivity, the scenarios of cultivar change and irrigation treatment, change of cultivated area and rainfed cultivation with supplementary irrigation had a positive effect on water, food and energy productivity index. After prioritizing the influential sub-scenarios with the TOPSIS multi-criteria decision-making model, the sub-scenario of wheat variety 6 with full irrigation treatment had the most positive effect on water, food and energy productivity and was identified as an indicator scenario for evaluating productivity in agricultural management.

In order to carry out the appropriate program for agricultural operations and to know the appropriate planting time of dry wheat crops, the length of the growth period and its beginning and end are special. The studies carried out during the growing period of dry wheat in the country are based on the growth degree day method, which does not exist for dry or semi-arid regions. In this study, the length of the dry season wheat growth period for a statistical length of 30 years (1371 to 1400) for 38 sinopic stations of the country by taking meteorological temperatures and precipitation, with the help of the proposed method of the ecological zoning guidelines of the Food and Agriculture Organization of the United Nations (FAO) and By finding the intersection points of the graphs of precipitation and 50% potential evaporation and transpiration, the beginning and the end, the length of the growth period has been estimated, which corresponds to the results presented for the length of the growth period in the ecological classification publication of the FAO organization. Results of the obtained results, Astara station with 301 days of growth period and Isfahan, Saravan, Tabas, Semnan, Zahedan and Kerman stations with 0 days of growth period are respectively the most and the least. to give have given. Also, the results showed that the use of the FAO method to estimate the length of the growth period in arid regions obtains more realistic estimates than the growth degree day method.

The use of methods to reduce energy consumption in greenhouses such as reduced heat losses, and improved efficiency of heating, cooling, and irrigation systems cancut energy consumption for the production of any crop to several times. The present research has designed and built an automated system for climate control of a rose greenhouse. This system is consisted of control and measurement stations. The control unit, itself, is consisted of a human-machine interface (HMI) device; while the measurement station is formed of one humidity, one light, and eight temperature sensors. Climate conditions of the greenhouse is received by the measurement station, there to be sent to the control one. Also, energy consumption in both systems are calculated and analyzed, too. The present research compares the impacts of the built automated system for climate control of greenhouse on the qualitative and quantitative traits of three cut-roses cultivars including 'Angelina', 'Samurai', and 'Red One' with the control system. Quality index and shoot weight of the cut-roses are improved under the automated system than the control. But there no difference could be found in traits of flowering stem length and number, stem diameter, number of lateral and blind shoots, internodes length, and vase-life, between the crops of two systems compared. The results also indicate a reduction in energy consumption under the automated climate management system than the control, equal to 12%. In sum, considering that the use of climate control system has improved the efficiency of energy consumption without having a negative impact on the quantitative and qualitative characteristics of the crop, it is recommended.

One way to increase crop production and productivity is to properly feed crop plants, which results in increased production per unit area. Chemical fertilizers and compost alone cannot provide for plants' needs. Therefore, mixing these two types of fertilizers in a specific ratio is necessary. The main problem with mixing compost and chemical fertilizers is controlling their mix ratio. In this study, a twin-shaft paddle mixer was designed, fabricated, and evaluated to solve the problem of adequately mixing compost and fertilizer urea. The constructed device includes a 1.5 kW electromotor, chassis, paddle, and chain-sprocket mechanism. Experiments at three levels of the axis rotational speed of 20, 40, and 60 rpm and three levels of mixing path length of 72, 108, and 144 cm, and two levels of paddle angle of 45 and 60-degree with a rotating axis in three replications under factorial test based on completely randomized block design. The analysis of variance of a distance effect on the measured urea-compost ratio showed that the rotational speed of the axes, the paddles angle, and mixing length of 1 and 5 % level were significant. Also, the results of the comparison of mean effects of treatments showed that the paddle angle of 45 degrees, the rotational speed of 40 rpm, and the mixing length of 108 cm had the best performance.

This study aims at investigating morphological and physiological characteristics as well as water use efficiency of the stock plant in various low irrigation treatments and culture media. For so doing, a research has been conducted in the form of split plots with a completely randomized block design with three replications in the crop year 2018-2019 in the research greenhouse of the College of Abouraihan, University of Tehran. The treatments include four culture media (perlite, perlite + enriched manure, perlite + zeolite, and perlite + vermicompost) and three low irrigation levels (100% (control), 75%, and 50% of water needs). Results indicate the significant effects (P < 0.01) of culture medium on plant height, stem diameter, leaf area, root fresh and dry weight, plant fresh and dry weight, as well as water use efficiency, and the perlite + vermicompost media improves all these traits. Moreover, severe irrigation treatment (50%) has had negative effects on plant growth parameters, i.e., root fresh weight and diameter, while irrigation at 75% of water needs does not have any undesirable effect on plants, significantly increasing water use efficiency (P < 0.01). The perlite + vermicompost with 75% low irrigation treatment increases the water use efficiency by about 1.8 times, compared to the control in the perlite culture media. Due to the decrease in the quality of growth characteristics in severe low irrigation treatments (50%), this plant’s production is recommended in irrigation at 75% of the water needs.

A solution for optimal management of water resources is to add superabsorbents to the soil to increase water consumption efficiency. Due to the importance of soil infiltration in the design and evaluation of surface irrigation methods, several methods including multi-level optimization, Elliott and Walker two-point method, IPARM and SIPAR-ID were used in this study to estimate the volume of infiltrated water in soil with the presence of superabsorbents. This study was carried out during spring and summer of 2019, in experimental filed of Aboureyhan College of Tehran University. With 5 times irrigation in 10 furrows, two dosages of A200 and Stockosorb superabsorbents (16 and 32 g/m2) and two flow rates (0.3 and 0.6 Ls-1). According to the results, adding superabsorbent to the soil increased soil infiltration. The effect of superabsorbent was reduced with the increase of the flow rate to the furrows (In low flow rate from 5.9% to 18.9% and 5.5% to 18.1% in high flow rate). Stockosorb superabsorbent had a greater effect on increase of water infiltration in the soil compared to A200 (3.4% and 3.3% for low and high dosages of superabsorbent and low flow rate and respectively 0.5% and 1.7% in high flow rate). Multi-level optimization method estimated soil infiltration parameters with the lowest relative error (1%). Having high relative error, the SIPAR-ID model did not perform properly during the evaluation. Results also showed that with increasing the flow rate to the furrows, the performance of the IPARM model and two-point method decreased.

Today, the use of biodegradable coatings has become an effective solution for pelletized agro-biowaste fertilizers due to the synchronizing of the nutrient release according to the plant requirements and reducing the environmental issues. In this study, three agro-biowaste compost including poultry manure (40%), cattle manure (30%), and agricultural biomass (30%) were mixed at the 40% moisture content, and then the pelletization process was carried out using the screw extruder. A factorial experiment in a completely randomized design with three replications was developed for assessing the effect of four biodegradable coating materials (humic acid, canola oil, corn starch, and nano-silica) and three coating methods (dip coating, spray coating, vacuum coating) on sustainability attributes of coated compost pellets such as pellet disintegration time, water absorption, humidity absorption, and water contact angle. The results showed that the canola oil – vacuum method applied for coated compost pellets with disintegration time (1735 min), water absorption (57.6%), humidity absorption (4.3%), and water contact angle (69°) was the best treatment. This coating method showed a 36-fold increase in disintegration time and a 3.7, 7, and 1.6-fold decrease in water absorption, humidity absorption, and water contact angle, respectively as compared with uncoated compost pellets. The nitrogen release rate of the coated compost pellets showed that the amount of total nitrogen at disintegration time was 25%. Also, 75% of nitrogen was released into the soil during 55 days, which confirmed experimental results and improved the nitrogen release rate by 45 days as compared with uncoated compost pellets. Overall, from the results of this study, it can be concluded that pelletized compost fertilizer which was coated by canola oil-vacuum method, shown a high resistance to water, enhanced sustainability and reduced nitrogen-release rate property as it could supply nutrient to the plant for a longer period.

To increase the applicability of compost for agricultural utilizations on a large scale as a sustainable slow-release nitrogen fertilizer, as well as reducing the limitations of their handling, transportation, and storage, it is important to improve their physical and mechanical properties, and pelletization is the most applicable process to achieve these goals. In the present study, the pelletizing process of sugarcane bagasse compost using a closed-end die within a single pelletizer unit was investigated. Composted hammer milled sugarcane bagasse with three particle size (1, 2.5, and 4 mm), three moisture content (8, 12, and 20 %) under three compaction pressure (50, 100, and 150 MPa) was densified and the effect of these factors on specific energy consumption, maximum breaking strength and density of produced pellets were evaluated and optimized by response surface methodology (RSM). The optimum value of specific energy consumption (2.11 MJ/t), maximum breaking strength (28.35 kg), and particle density (0.871 g/cm3) were suggested from BBD-RSM for pelletization of sugarcane bagasse compost under optimal conditions of using 4-mm particle size, 20 wb% moisture content and 50 MPa compaction pressure with desirability function of 0.706. Then, the rate of nitrogen release in soil and water for pelletized mixed sugarcane bagasse compost-urea fertilizer at a ratio of 1:1 wt% was investigated. The results of the nitrogen release rate showed that 61% of nitrogen was released into the water during five days while the release of nitrogen in soil was 80% during 98 days for pelletized mixed compost-urea fertilizer. In general, the findings of this study showed that the pelletized fertilizers produced from the compost-urea mixture are capable to supply nitrogen to the plant for a longer period relative to conventional nitrogen fertilizers such as urea. It could be deduced from this research that pelletized mixed compost-urea fertilizers have great potential for use in crop nutrition as a sustainable slow-release nitrogen fertilizer.

The study was conducted at the experimental farm of college of Aburayhan of University of Tehran located in Karaj. The aim of this study was to investigate the effect of using superabsorbent polymer on flow hydraulic parameters of the flow and water infiltration in furrow irrigation. For this purpose, two types of superabsorbent A200 and Stockosorb with two values of 16 and 30 g/m2 of soil under two different flow rates (0.3 and 0.6 L/s) were used. The experiment was carried out in five irrigation regimes and in non-cultivated conditions in the summer of 2018. The results showed that both superabsorbents increased the time of the advance and recession and increased their amount by increasing the amount of superabsorbent. Also, the results showed that the addition of super adsorbent to soil decreased the runoff and increased the amount of infiltration, and with the increase of the flow rate to the furrows, the effect of superabsorbent was reduced. Stockosorb superabsorbent had a greater effect on the increase in advance and Recession times and enhance of water penetration in the soil.

Light is one of the main factors regulating plant growth and development. Among different aspects of light, light intensity has a great effect on plant responses, such as plant's water relations. Light intensity in greenhouse is lower than normal in winter and excessive light intensity in the summer. The aim of this study was to evaluate the effect of light intensity on performance, evapotranspiration, water use efficiency of lettuce in a completely randomized design with four treatments and twelve replications in the Park of Science and Technology in Aburaihan campus of University of Tehran. Since blue and red spectra are the main wavebands involved in growth and gas relations, the present experiment was done by using spectra composition of red and blue with a ratio of 70 percent red and 30 percent blue with four different intensities including (T1) 75 μmol.m-2.S-1, (T2) 150 μmol.m-2.S-1, (T3) 300 μmol.m-2.S-1 and (T4) 600 μmol.m-2.S-1. The studied traits included growth characteristics associated with water use efficiency. Based on the obtained results, the highest fresh weight was obtained from T3 and the lowest fresh weight was obtained under light intensity T3 with 73.52 and 17.31 respectively. Increased light intensity caused an increase in dry weight and leaf area. Highest growth simulation was observed under T3. Furthermore, the highest and the lowest water use efficiencies were observed in plants that were grown under T4 and T1.

More than 75% of the rice cultivated land is located in the northern provinces of Mazandaran, Gilan and Golestan. In recent years, the second cultivation of rice has been developed. This research was carried out in Mazandaran province, Khazarabad region of Sari, for the Premature varieties of local Tarom during two seasons for second cultivation in (2016 and 2017). In this study, triplicate overflow was used to measure inlet and outflow discharges. Three lysimeter were used to determine the water requirement of the fields. The water requirement was calculated from the input difference, which included the amount of water input that was calculated by overflow, as well as rainfall and output, including (evapotranspiration, permeability of the lateral submerged area and drainage water) Also, the irrigation of three stages of crop, reproductive and rearing for the first crop of (2015) was estimated to be 1.10, 1/5, 1/2 The coefficient for the second cultivation of (2016) was ./98, 1.4, 1.03, and the second planting factor of 2017 was ./95, 1.34, 1/01 respectively. The results show that the amount of water requirement in the second cultivation of 2016 and 2017 is 33%, 27% less than the first crop of 2015 respectively. Also, the average of crop factor in three stages of growth in the second cultivation of 2016 and 2017 was 10% and 12%, respectively, compared to the first one of 2015. Therefore, in regions where there is a good level of rainfall during the second crop, it is possible to recommend the second crop of rice.

Considering the drought crisis and high consumption of water in paddy fields, it is useful to present strategies in order to increase irrigation efficiencies. However, one of the methods to increase productivity in the agricultural development of cropping and ratoon culture that has an important role in the economy of rural households. Therefore, it is necessary to determine the amount of water needed for the second cultivation of rice and the cultivation of ratoon for water resources planning. This study was conducted in Mazandaran province, Sari. The local Tarom early varieties during two crop seasons in 1395 and 1396 years of regional ratoon also was conducted in 1396. To measure the input and output flows, triangular overflow was applied to the treatments and three lysimeters were used to determine the water requirement of the fields. Water use efficiency and water productivity were investigated in each treatment season. The results showed that the highest consumption efficiency was measured at 61% in ratoon cultivation. The water use efficiency in ratoon cultivation increased by 39% compared with the second cultivation of 1395 and 42% compared to the second cultivation of 1396. Water productivity in the second cultivation of 1395 and 1396 and ratoon cultivation in 1396 was 51%, 33% and 40%, respectively. Therefore, in areas with enough rainfall during the second cultivation and cultivation of ratoon, second cultivation of rice and rattan culture can be recommended.

Despite the well known roles of phosphorus in plant nutrition, plant responses to this nutrient element have not yet been found out. Therefore, in this study different levels and forms of phosphorus fertilizer applied on two white and red cultivars of stock flower under greenhouse conditions and some growth and development indices were evaluated. The experimental conducted was completely randomized design with four replications. Treatments included the control (without P application), granular superphosphate fertilizer at four levels (0, 50, 100 and 200 mg.kg-1 of soil), liquid phosphate fertilizer at four levels (0, 50, 100 and 200 mg kg-1 soil) and bio-fertilizer phosphate (Barvar2), 100 g in 2000 ml of water. The results showed that there were significant differences at 5% among treatments for most of traits. Many parameters such as the number of flowering stems, inflorescent length, number of flowers in inflorescence, number of petals in flower, flowering stem length, leaf number and stem diameter were recorded higher in 200 mg P/kg soil (liquid form) compared to the control and other treatments. Regarding these traits, 200 mg granular and then bio-fertilizer were the next best treatments, respectively. Phosphorus levels of 50 and 100 mg/kg soil were resulted in lower amount of yield and quality parameters. Although the two cultivars were relatively similar, but white cultivar showed higher amounts of measured traits.

Composting livestock manure and municipal solid waste is an appropriate method for waste management in order to stabilize organic wastes. The low specific mass of compost causes problems in transportion and storage activities and increases the costs. In this study some parameters affecting the pellets production was investigated. Parameters considered were: particle size (1 and 2 millimeter), pellet moisture content (25, 35 and 45 percent) and kneading length (1, 2 and 3 meter). Results showed that the specific density of pellets produced under both levels of particle size, increased with increasing the Length of kneading at all levels. Interaction effect of moisture content and kneading length on the rate of fractured pellets showed that, the maximum amount of force was (556.32N) which belonged to treatment with (moisture content of 35% and length of kneading of 3 m). Also the interaction effect of particle density and length of kneading showed that maximum toughness value was (1.03 MJ/m3) which belonged to particle density of 1mm and kneading length 3 m.

This pot experiment was conducted under greenhouse conditions to evaluate the effects of different levels and forms of phosphorus fertilizers on quantitative and qualitative traits of two cultivars of Mathiola incana, based on a completely randomized design with eight treatments and four replications. Treatments were application of granular and liquid forms of triple superphosphate, both at three levels (50, 100 and 200 mg/kg soil), a biofertilizer (100g/2000ml Barvar-2) and control (without any fertilizer application). Results showed that application of 200 mg/kg soil of liquid phosphorus (PL3 treatment), granular form (PG3 treatment), and biofertilizer (PB treatment) significantly increased all plant growth characteristics (morphologic and physiologic), compared to control plants. The highest chlorophyll a and b contents in both cultivars were obtained in 200 mg/kg of liquid fertilizer treatment (PL3) and 200 mg/kg of granular form (PG3). The highest leaf phosphorus concentration was measured in PL3, PG3 and PB treatments. In both cultivars, the highest shoot fresh and dry weights, length of flowering stem, inflorescence length and number of flowering buds in inflorescence were obtained in PL3, PG3 and PB treatments. The highest root fresh and dry weights were obtained in PB and then PL3 treatments, showing significant difference with other treatments (P≤0.01). In this study, the highest values of measured traits were observed in higher concentrations of liquid phosphorous treatments, compared to granular form. However, the Barvar2 biophosphate treatment (PB) has also led to significant growth improvement and highest fresh and dry weight of root, and therefore is recommended for production of Mathiola incana.

Nowadays compost fertilizers are suitable alternative to chemical fertilizers, due to the threats for human health and agriculture products. The most important problems for applying the compost fertilizer in the farm are: transportation (high volume), high moisture content, spreading problem, impurity such as dust and storage. To solve the problems mentioned, pressing process such as converting the compost to pellets and granules are suggested. In this research the effects of some granulation parameters on the percent of useful granules in a laboratory scale rotating drum was evaluated. The percentage of useful granules decreased by increasing the granulation time and increased by increasing the percentage of drum filling. The optimal conditions for granules production was achieved at drum rotational speed of 40.38 rpm, granulation time of 15 min, drum filling of 10% and molasse percentage of 40.97. According to these conditions, the response for useful granule was estimated as 81.6% with R2 of 0.924.

Today the chemical fertilizers are replaced with organic fertilizers due to the bad effects on human health and agricultural soils. There are barriers against useful utilization of organic fertilizers such as transportation (high volume), high moisture content, uneven distribution of fertilizers, dust production and storage. One of the solutions is densification of manure as pellet or granule. The effects of process parameters were evaluated in laboratory scale rotating drum. The effects of parameters such as drum rotational speed, granulation time, filling percentage of drum and percentage of molasses were investigated on the fracture force of granules. The results showed that all parameters and also interaction of drum rotational speed and granulation time have significant effect on the fracture force. Also, the results showed that with enhancement of granulation time, percentage of drum filling and percentage of molasses, resistance to failure of the granules increased.

The present study aimed to evaluate the effect of organic fertilizers on growth and yield of spring wheat under deficit irrigation conditions in the Agricultural Research Station located in the city Pakdasht Aboureyhan Tehran University in Tehran during the crop year was 90-1389. To test the split plot design in randomized complete block design with three replications. Main stress irrigation, in three levels (no irrigation at flowering stage (a1), grain filling (a2) and normal irrigation area (a3)) and the operating subsidiary in four levels (15 tons of compost fungus 15 tons of manure (b1) 60 kg of nitrogen fertilizer net 15 tons of manure (b2), 60 kg of nitrogen fertilizer net 15 tons of compost fungus (b3) and 120 kg of pure nitrogen (b4) respectively. In this experiment, the treated water irrigation on the weight of biological function seed, grain number per spike, number of spikelets per spike, harvest index, seed weight and number of fertile spikelets per spike had a significant effect. fertilizer treatments on weight and biological yield, grain number per spike, number of spikelets per spike, harvest index, number of spikes per square meter, grain weight and number of fertile spikelets per spike had a significant effect. use of organic fertilizers in terms of environmental stress, especially drought stress causes stress effects can be reduced and plant show better performance. Organic fertilizers improve soil properties, especially soil moisture holding capacity to create aggregate, helps increase the amount of moisture available to plants. use a combination of organic and chemical fertilizers can be negative effects of fertilizers reduce chemical.

In this research the impact of climate change on crop yield، and water requirement of the main crops (wheat، barley، corn and alfalfa) has been evaluated in Hashtgerd plain with respect to the uncertainty of Atmospheric Ocean General Circulation Models (AOGCMs). To produce monthly temperature and precipitation scenarios،، temperature and precipitation were extractedfrom nine AOGCMs under the A2 emission scenario (CCSM3، CGCM3، CSIRO Mk3، GFDL CM2. 1، GISS ER، HadCM3، ECHAM5، MIROC-med، PCM) in the period 2010-2100 AD. Using Monte Carlo and weighting methods، 2000 time series of temperature and precipitation scenarios were produced for each cell (5°×5°) in the whole plain. Afterwards، these scenarios were downscaled by change factor method for the area. Finally، using AEZ/GIS and Hargreeves-samani approach، the potential yield، and the crop evapotranspiration was assessed in the region in the period 2010-2100. The agricultural water productivity was also studied in this plain.، The results were depicted in range of variation in each period. On the whole، variation of the results revealed the enhancement of water requirement and reduction of the yield in the future periods in this area. Water requirement increase in wheat 15-28، maize 9-14،alfalfa 18/6-34/7 and barely 10-21 millimeter in each periods to 2100 year. On the other hand the range of decrease for wheat، barely، alfalfa and maize will be 50-138، 44-136، 327-508 and 17-24 kilogram per hectare respectively. The results also showed decrease in variation of water productivity in all crops in future periods. Furthermore، in this regard، alfalfa has had the biggest (104-156 gram per Cubic Meter) and wheat the smallest (55-93) reduction in productivity.

Water productivity is a function of crop yield and management operation. Determination of different yield levels through field experiments is difficult. Therefore, applying simulation model is an approach which makes possible to assess water balance, simulate growth process and survey different scenarios. Using the CropSyst crop growth model to analyze water productivity, as an indicator of water use efficiency (WUE) at the basin scale, and evaluation of management scenarios in Karkheh basin in west of Iran was studied. The vast range of WUE (0.27-0.45) in this region shows that less water expenditure is able to increase agricultural products. Results of model study showed that achieving of soil initial moisture to field capacity about 19.6%, leave total crop residues, early rainfall and sowing date in comparison with conventional conditions, and seed density (300 seeds/m2) are effective to increase water productivity and yield.

The objective of this research was to study the effect of fertilizer management on the yield increase of crop plants. The extra amounts of applied fertilizers were studied by comparison between allocated, applied and recommended fertilizers’ amounts for: wheat, barley, corn and alfalfa with four replicates and the other data was gathered via questionnaires. Soil analysis of phosphorus, potassium and nitrogen amounts was performed in 20 fields and analysis of data was conducted base on complete randomized block design. Comparison of the averages was showed that there were significant differences between the amounts of allocated, applied and recommended fertilizers (P? 0.05). The average amounts of extra applied and extra distributed fertilizers were 382.9 and 150.6 Kg.ha-1 more than the recommended amounts, respectively. However, there was no significance increase in yield. 12 and 28% of farmers used the fertilizers in the basis of recommended and allocated, respectively and 60% of them used more than recommended amounts. Excess fertilizer application due to improper management causes reduction of soil and water quality.

Wheat yield and water productivity are affected by water and nitrogen fertilizer management and climatic data. The aim of the present study was to assess the efficiency of artificial neural networks (ANNs) models in predicting winter wheat yields and water productivity using climatic data and seasonal water-nitrogen variables. The calibration and verification of the proposed models were accomplished using data from field experiments carried out in three years. The models were evaluated using several statistical error and goodness-of-fit measures, including the coefficient of determination, root mean square error (RMSE), mean bias error (MBA), and standard error (STE). The applied ANNs models had desirable accuracy in estimating crop yields and water productivity. ANN models consistently produced more accurate predictions than multiple linear regression models. The sensitivity analysis indicated that the productivity of wheat water has the highest level of sensitivity to the seasonal water use. The data generated here suggested that maximum and minimum wheat water productivity would be achieved with about 272 and 490 mm seasonal water use, which were determined 1.55 and 0.81 kg m-3, respectively. The applied ANNs can provide the background for promoting the water productivity for this strategic crop in different weather condition, and give us the possibility of the logical and economical use of water sources and nitrogen and also programming the combined usage of both resources in the study area.