Estimation of optimum fertilizer rates is needed because of growing economic and environmental concerns. Optimum fertilizer rates can be determined by fitting statistical models to yield data collected from N fertilizer experiments. The main goal of this research was to compare and evaluate quadratic, square root, Mitscherlich, rectangular hyperbola, linear plus plateau and quadratic plus plateau models for describing the response of sugar beet to N fertilizer. Data used were obtained from a furrow Irrigation system experiment with five N fertilizer rates: zero (control), 60, 120, 180, and 240 N kgha-1 with three replications in Ekbatan Research Station, Hamedan, Iran, during 2003 and 2004. Economic optimum N fertilizer rates were obtained based on fertilizer and sugar beet price during 2003 and 2004. Economic, optimum N fertilizer rates varied depending on the fertilizer to crop price ratio and models used. Results of this research showed the quadratic model described the yield responses and economic, optimum N fertilizer rate in sugar beet cultivation better than the other models. Economic, optimum N fertilizer rates due to this model were 235.8 and 248.9 kgha-1 in 2001 and 2002, respectively. Economic optimum N fertilizer rates based on N fertilizer subsidy and non-subsidy prices were 234.7 and 225.1 kgha-1 for 2003 model, and 247.9 and 240.8 kgha-1 for 2004 model, respectively.

In order to identify the correlations and relationships between different traits in the bread wheat, 30 genotypes were investigated as sub-factors under the split plot experiment in the completely randomized design in greenhouse and the randomized complete block design in the field with three replications under the normal Irrigation and post-anthesis water stress conditions. The results of the canonical correlation analysis showed that at both normal and moisture stress levels, there was a significant correlation between the pair of canonical variables obtained from the phenological traits and the yield components. Under the normal conditions in the greenhouse, to increase the spike density and length, the number of days to 50% flowering can be considered as a suitable selection criterion. According to the results of canonical correlation analysis, under the stressed conditions in greenhouse, to increase the spike length, the number of days to the heading, maturity and 50% of flowering were among the important and effective factors. Under the optimum Irrigation conditions in the field, the number of days to maturity was considered as one of the factors influencing the seed weight per spike. The results of canonical correlation analysis under the field stress conditions showed that to increase the 1000-seed weight, the number of days to maturity can be considered an appropriate selection criterion.

Background: Chemo mechanical debridement is an important part of endodontic treatment. Elimination of pulpal tissue, microbiota and their by-products, organic and inorganic debris removal by using instruments and intracanal irrigants are objectives of this important phase of treatment. The aim of this study was to ex-vivo evaluation of smear layer removal in conventional clinical methods, Passive Ultrasonic Irrigation, Laser Activated Irrigation.Material and Methods: 54 anterior mandibular teeth was used in this study. After preparation of samples, they were divided in to 3 groups of Conventional Irrigation +Smear layer removal, Passive Ultrasonic Irrigation, Laser Activated Irrigation. Then, the samples were cut longitudinally in mesiodistal direction for examination by SEM (1500X) for assessing smear layer removal.Results: In coronal, middle and apical one third, the best result was obtained from Conventional Irrigation + Smear layer removal group for smear layer removal.Conclusion: According to better smear layer removal in Conventional Irrigation + Smear layer, it is considered as gold standard protocol and other groups cannot be a suitable substitution for this method.

To investigate the effects of fertilizer regimes on quantitative and qualitative traits of Dracocephalum kotschyi Boiss, a field experiment at three replications with the Split Plate arrangement in a completely randomized block design was conducted in the Research Field of Tarbiat Modares University during the 2017-18 growing season.Water deficit stress (Irrigation after discharging 20 (optimal Irrigation), 40 (mild water deficit stress), 60 (moderate water deficit stress) and 80% (severe water deficit stress) of water used (available water)) in the main plot and fertilizer regime (urea, nitroxin, vermicompost, azocompost and no fertilizer) in the subplot were studied. The results showed that the highest leaf fresh weight (1797 kg ha-1) and total biomass (2957 kg ha-1) were obtained by application of urea in mild water deficit stress condition and the highest dry matter digestibility percentage was observed in azocompost treatment in moderate water deficit stress condition (57.8%). The highest crude protein was produced in severe water deficit stress condition (19.72%) and moderate water deficit stress (18.4%), respectively.. The highest percentage of water soluble carbohydrate and neutral detergent fiber were obtained from no fertilizer in moderate water deficit stress (22.06%) and application of urea in severe water deficit stress conditions, respectively. Mild water deficit stress application to produce high biomass is recommended for Dracocephalum kotschyi Boiss. According to the results, application of urea in mild water deficit stress was selected as the best treatment to produce forage 32% more than control.

To evaluate the effect of nitrogen and water withholding in vegetative growth stage of corn on efficacy of nicosulfuron and 2,4-D+ MCPA an experiment was conducted as a factorial arrangement in a randomized complete block design with three replications at Tarbiat Modares University in 2017. The first factor contained four treatments including application of nicosulfuron, 2,4-D+ MCPA, weed free and weed infested as control. The second factor consisted of normal Irrigation and water withholding from 4 to 8 leaf stage. Third factor contained either urea application or no fertilizer application. Normal Irrigation and nitrogen fertilizer application significantly increased nicosulfuron and 2,4-D+ MCPA efficacy in weed control and total weed dry weight decreased to 341 and 361 g.m-2 respectively compared 1370 g.m-2 as weed infested. Nicosulfuron and 2,4-D+ MCPA reduced weed total dry weight significantly under Irrigation withholding. Grain yield increased with application of nitrogen and nicosulfuron. Grain yield was higher with application of 2,4-D+ MCPA than nicosulfuron without nitrogen application under Irrigation withholding. Application of nicosulfuron with nitrogen application provided satisfactory weed control and increased grain yield.

Water is one of the most important resources needed by human society and the first and most important factor for the production of agricultural products, more than 90% of this vital liquid is consumed in this sector. One of the most important factors that affect the performance of a water conveyance and distribution network is the water distribution and delivery program. In order to obtain turnouts’ discharges, the water requirement of the eastern Aghili area was estimated using the Global Land Data Assimilation System (GLDAS) and controlled using the results of the NETWAT model. For this purpose, three-hour evapotranspiration was estimated with GLDAS, and the six-hour discharges of turnouts were calculated according to the cultivated area of each turnout and Irrigation efficiency. The hydraulics of the eastern Aghili canal were simulated using the above-mentioned data for six hours. The results showed the appropriate accuracy of GLDAS so that at a maximum of 12.7%, GLDAS underestimated the evapotranspiration values compared to NETWAT. The minimum values of efficiency and adequacy indicators of 0.95 and 0.94, respectively, were obtained, which are in the "good" performance class.

Surge Irrigation, an intermittent release of water into furrows is an efficient method of water conservation if the flow and frequency of water delivery are optimized. It increases the advance velocity, causes uniform distribution over the furrows, and reduces deep percolation losses. The objectives of this study were to compare yield indices for surge flow and continuous flow, and to evaluate cycle ratios and suitable input discharge in the study area, and also to determine the difference of advance velocity of the wetting front between surge Irrigations and continuous flow Irrigations. Seventy meter long furrows, 0.5 and 2 lit/s discharge rates, and various pulse ratios were compared with the constant inflow. Field experiments were conducted including determination of the number of furrows and the number of surges, and continuous flow treatments (2 discharges and various cycle ratios for surge flow). Advance velocity, in-and-out flows, and soil water content prior and after the termination of Irrigation were measured at the Khalatpoushan Research Station of the Tabriz University. Then flow parameters and infiltration rate for furrows were simulated using the SIRMOD surface Irrigation model for both the surge and constant flows. In order to compare the advance velocity of wetting front for surge and continuous Irrigations, the HYDRUS 2-D model was used for simulating the advance of wetting front in the wet soil volume in the furrow. The results of simulation show that the final infiltration rate during surge flow was half of continuous flow for one of the treatments. Advance velocity of wetting front in surge treatments was more than continuous treatments with the same volume of applied water. Overall, the S22 treatment (the inflow of 0.5 lit/s and the pulse ratio of 1:4) had the best performance, and S13 treatment (the inflow of 0.5 lit/s and the pulse ratio 2:3), had the poorest performance, even worse than constant flow treatments.

Agricultural sector is the greatest user of water in Iran, and increase of the consumption efficiency is necessary by considering the limited water resources in the recent years. Hasanlu Irrigation and drainage networks as a part of a larger project of Naghdi plan is one of the country's largest projects in the field of development of pressurized Irrigation systems. Hasanlu network supplies water to the systems of sprinklers, surface gravity Irrigation, and hydroflums based on the available pressure head at the relevant sites. In this research, geographic information systems were used as a framework for storing, management, processing, analyzing and visualization of spatial information of Hasanlo project phase 1 to evaluate water management of this plan. For this purpose, the coefficient of uniformity and distribution uniformity in sprinkler Irrigation calculation toolbox developed and added to GIS as an extension, to simulate and evaluate the single or multi riser uniformity tests. Also, the risers discharge and application pressure were recorded at the site during the operation of the project. Results indicated that the pressure of risers varied from 0. 5 to 3. 9 bar and average Christiansen’ s coefficient of uniformity (CU) was under 50% that indicated poor water management in the farm level. Also, the satisfaction of stakeholders was in medium level.

to attention of water limitation in Soybean cultivation, tolerance cultivar selection for increasing grain yield is very important. In this order a research carry out in field research Islamic Azad University of Karaj branch using of factorial split in form of randomize complete block design in four replication. Main factors include Irrigation rate at two levels S1=%40 and S2=%70 water available depletion and Irrigation method at three levels M1=Normal furrow, M2=With one furrow interval M3=Two row planting plots and sub factor include two cultivar V1=Williams and V2=L17. Measured traits including: plant height, number pod per plant, harvest index, Total dry weight, 1000 grain weight and grain yield per unit area. According to experimented results interaction effect Irrigation. Cultivar at p£5 and low Irrigation. Cultivar at p£%1 on grain yield was significant. Williams cultivar in low Irrigation have been highest grain yield (1909 kg/ha). The highest and lowest grain yield in L17 cultivars obtained in low Irrigation (1.74 kg/ha).Also highest grain yield Williams cultivar obtained in one furrow interval Irrigation method.