فهرست مطالب mojtaba cheraghizade

According to the Statistical Center of Iran, the country's population between 1957 and 2017, has increased approximately from 19 people to 80 million. With population growth, the water demand is increased and water resources are threatened cumulatively. Agriculture is recognized as the main water consumer in the country. Due to the arid and semi-arid climate of the country, it is essential to use water reduction strategies such as deficit irrigation (DI) and partial root zone drying (PRD) deficit irrigation in agriculture. In case of water shortages, DI is an optimal solution for production, which is usually accompanied by a reduction in product per unit area. The base of PRD is keeping dry the half of root while irrigating the other half. The plant root in the wet area absorbs enough water. The other part of the root in dry soil, with a reaction to dryness and sending symptoms to the stomata, affects their opening size and reduces water losses. Sunflower is one of the four major oil producing plants in the world. The high volume of this product's import causes the country's strong dependence on oil import and the currency's outflow from the country. Although all living and non-living stresses are considered to be major factors in reducing production, water deficit stress is one of the main factors limiting the production of sunflower; Therefore, studying the reaction of this plant to different drought stress conditions and providing a solution to reduce the negative effects of dryness would be essential.

The present study was conducted on sunflower plant (Hysun 25) in a research farm of Sari Agricultural Sciences and Natural Resources University (SANRU) in 27 plots (5 × 5 square meters). Each plot consisted of 6 rows of planting at a distance of 75 cm from each other and 5 meters long. Sunflower seeds were planted at a depth of 4 cm from the soil and at a distance of 20 cm from each other. The experiment was conducted by using split-plot design, with three main factor (irrigation interval) and three sub-factor (irrigation water amount) in randomized complete block design in three replication. The irrigation intervals were irrigation after 20, 35 and 50 mm evaporation from class-A evaporation pan (F-20, F-35 and F-50 respectively). The sub-factor was irrigation water in levels of 100%, 75% and 55% of water demand (FI, PRD-75 and PRD-55 respectively). Controlling the volume of water delivered to each treatment was carried out using a volumetric flow meter. The application of irrigation treatments was carried out six weeks after planting. The irrigation for FI was conducted regularly at both sides of the root and for PRD it alternatively changed at the right and left sides of the root. The studied traits were irrigation water use efficiency (IWUE, kg/m3), height (H, cm), the flower diameter (D, cm), the seeds number per flower (SN), the 1000 seeds weight (W, gr) and the chlorophyll index (SPAD). Statistical analysis of data conducted by SAS software using Duncan test (1% level). Diagrams extracted by Microsoft Excel software.

Evaluation of irrigation interval factor based on the experiment two years data, indicated that the best results for plant growth parameters was for F-20. Also, the best results for sunflower plant growth parameters was for FI. According to the significant difference between FI and PRD-55 at most of the growth parameters, it’s suggested to conduct PRD-75 for PRD. For the irrigation interval factor, there was significant difference for most of the plant growth parameters between F-20 and F-50. Therefore, considering this case as well as the problem of increasing the operating cost by reducing the irrigation interval, F-35 is recommended for irrigation interval. It’s concluded that there was significant difference between all of the irrigation interval treatments by analyzing the IWUE trait. The highest amounts was for F-50 and the lowest was for F-20. Despite the increase in the value of IWUE in PRD-75 in comparison with other treatments for each two years of the experiment, this difference was not significant. According to the non-significant difference between F-35 and F-50 for IWUE at the second year of the experiment and this trait relative increase at PRD-75 in comparison with two other treatments, it’s suggested to conduct PRD-75 with F-35 to have higher IWUE.

Simultaneous analysis of sunflower’s IWUE and its growth parameters showed that it could be possible to save in irrigation water use and increase the IWUE with the lowest decrease in the sunflower plant growth parameters by applying PRD-75 and F-35.

The current study was conducted at Sari county prior 2015 and 2016 seasons with split plot design with three main factors (irrigation interval) and three sub main factors (irrigation water amount) in a complete block design in three replications. The irrigation intervals were irrigation after 20, 35 and 50 mm evaporation from class A evaporation pan (respectively F-20, F-35 and F-50). The statistical analysis of data was conducted by SAS software using Duncan test. Due to the non-significant difference for seed performance (SP) trait between FI and PRD-75 treatments, it could be possible to save approximately 13% of water by applying PRD-75. The F20-FI and F20-PRD75 treatments had the best results for SP respectively. F20-PRD75 and F35-FI had the best results for oil performance.

In order to produce the world’s growing population food demands, it would be necessary to increase the productivity. Most of this increase should be gain by funding for improving irrigation and drainage at current fields. High costs of these projects and the funds’ limitation make challenges to conduct the projects; so in order to have optimized use of the limited funds, it would be necessary to spatial prioritize the projects. At the current study spatial prioritization of subsurface drainage within the Alborz irrigation and drainage project was evaluated by using geographical information system (GIS). Prioritization was done based on the electrical conductivity and depth to water table. After determining limitations for effective factors on positioning, the interpolation done and interpolated maps were exported. After complexion of the interpolated maps for different factors, the prioritization map for conducting subsurface drainage was gained. The geostatistical analysis tool of ArcGIS software was used for interpolation. According to the results the kriging method had acceptable results for interpolation. After positioning the locations with various prioritizations, it founded that an area about 10300 ha (about 54.64 % of total area) was in the 1st and 2nd prioritizations. Generally these lands were at the northern half of area near to Caspian Sea. The main problems of these lands were salinity, swamplands or mixture of these two factors. According to the positive effect of drainage on rice productivity as one of the main crops of the area, conducting subsurface drainage systems for higher priorities is suggested.

The accessible water resources would not be able to meet the different needs erelong. Inevitably this would cause to search for newer lands for irrigation. According to the water resources’ limitation and the necessity of using the pressurized irrigation systems to gain the optimum use of the available water resources, it would be necessary to determine suitable lands for agriculture and pressurized irrigation. The land suitability (LS) classification is defined as the determination and classification of specific land areas according to their suitability for the desire use. The parametric evaluation system (PES) makes it possible to have the best decision by ranking different effective factors on the goal parameter. By considering that the underlying management and proper planning and optimum use of resources requires accurate and detailed information of the area of interest, in this context, Geographical information system with the ability of spatial analysis capabilities, analyzing and integrating the map information, tables and reports, can play a great role in achieving the set goals.
At the current study the zonation of priority of applying drip irrigation systems (DIS) within Babol and Babolsar counties is done by parametric evaluation of some of soil physicochemical characteristics and water chemical characteristics by geographic information system (GIS). The soil characteristics were Texture (T), Depth (D), Slope (S), Acidity (pH), and Electrical Conductivity of soil saturation extract (ECe). The water characteristics were Chloride (Cl), Boron (B), Electrical Conductivity (EC), Sodium Adsorption Ratio (SAR) and Residual Sodium Carbonate (RSC). These data were obtain from Jahad e Keshavarzi (agriculture) organization of Mazandaran.
The evaluation of the soil parametric index (SPI) indicated that the most area (approximately 90% of the total studied area (TSA)) is “suitable”. The most area for water parametric index (WPI) (approximately 75% of the total studied area) was “currently not suitable”. The evaluation of WPI’s sub-indexes indicated that the most limitation levels (severe and very severe levels) were related to residual sodium carbonate (RSC) index (approximately 90% of TSA). It was 9.4%, 8.5%, 0% and 0% for chlorine (Cl), electrical conductivity (EC), boron (B) and sodium adsorption ratio (SAR) sub-indexes respectively.
According to the results to apply DIS at the studied area, the prevention considerations (to prevent emitters from clogging due to high levels of RSC), like pickling would be necessary. In addition using drippers which have less sensibility to clogging is suggested, in order to preventing drippers clogging at very severe damage possibility locations.