فهرست مطالب قربان قربانی نصرآباد

Crops with high WUE and appropriate irrigation methods are critical for irrigation water management. Because of the indeterminate growth habit of the crop, this issue is particularly important in cotton production. Under high irrigation conditions, the balance between vegetative and reproductive growth may be upset. There are many reports showing the superiority of belt irrigation methods over conventional methods such as furrow irrigation. Considering the limited water resources in Iran, this experiment was conducted to study the response of cotton cultivars to irrigation rates and methods.

In this experiment, foreign and domestic commercial cotton varieties were compared in terms of yield and water use efficiency (WUE), in the form of split blocks on CRBD with 3 replications in 2022-2023 cropping seasons. Irrigation after 30% and 100% water evaporation from the pan in the main blocks. 13 cotton varieties were established in sub-blocks (plots) as sub-factors. Cultivars included of Golestan, Latif, Sepid, B557, Khordad, Partow, Taban Mai, Maxa, Lider, Loduz and American Genetics.

the effects of treatments on all traits studied were significant. The interaction between irrigation and cultivar on the traits was significant, except for the number of sympodial branches and fiber content. In the first year, the yield of Golestan and Partov cultivars was higher than the others when irrigated after evaporation of 30% of the husk water. Golestan, B557 and Khordad had higher yield when irrigated after 100% evaporation, which was due to their ability to form and retain more bolls per plant. Sepid and Lodouz varieties had the lowest yield in the first year. In the second year, Golestn and Khordad were superior to the other cultivars when irrigated after 30% pod evaporation. When irrigated at 100% evaporation from the pan, Golestan, Mai, and Taban had higher yield. The lowest yield this year was obtained by Leeder and Loduz varieties when irrigated after 30% evaporation from the pan. The most likely reason for these yield losses was the loss of balance between vegetativeand reproductive growth, which resulted in completely excessive growth, especially in the Loduz variety. This higher vegetative growth resulted in a reduction of the WUE value.

the local cultivars Golestan, Khordad and Partow and the Turkish cultivar Mai showed higher yields under belt irrigation. Due to the high vegetative growth potential in Leeder and Golestan, irrigation management of these varieties is more important than that of the others.

Due to the scarcity of fresh water resources, one of the main solutions to supply agricultural water resources is the use of unconventional water, including agricultural water drainage, saline water resources and effluents. In Khuzestan province, a total of about four billion cubic meters of drainage water is produced annually. The volume of water in the Karun Basin alone is about two billion cubic meters per year. One of the areas where sugarcane drainage has accumulated and is now a serious concern is the 35,000-hectare sugarcane wetland, located south of Ahwaz on the border with Iraq. Drainage production due to various activities, especially agriculture in Khuzestan province, is one of the serious problems. Sugarcane production and fish farming are the main producers of drainage in southwestern Khuzestan. In order to optimal use of sugarcane drainage, the effect of these waters on the quantitative and qualitative properties of cotton in the Cultivation and Sugarcane Industry of Mirza Kuchak Khan during 2018 and 2019 was investigated.

Experimental cultivation was performed in 8 lines of 30 meters with intervals of 60 x 20 cm. The field soil had a silty to loamy clay texture.. The experimental design was split-split plots with 3 replications. Three planting dates: February 28, March 29 and April 29 as the main plot, three irrigation treatments including sugarcane drainage, Karun river water, and intermittent irrigation with Karun water and drainage (combined) as a sub plot and three cotton cultivars included Golestan, Khorshid and Shayan were considered as sub-plots. The first planting date was 28th February, after plowing, disc and fertilizing. Thus, fuzzy seeds were disinfected using carboxin tiram fungicide and Gachu insecticide and then planted at appropriate depth according to field soil conditions. Irrigation planning was done based on measuring the percentage of soil moisture before irrigation and the depth of root development. Thus, in each irrigation regim, one day before the irrigation operation by measuring soil moisture to a depth of 100 cm, soil moisture deficiency is determined according to the depth of plant development by considering the maximum amount of management allowed deficit (MAD) equal to 60% of soil water holding capacity. In order to measure the yield components, five plants in each treatment were identified and measured on these plants. Cotton was harvested three times. Data were analyzed using MSTATC software and Duncan test. Finally, the best treatments were identified and introduced in terms of planting date, type of irrigation and cultivars that have better yields.

The results showed that the highest yield with 1712 kg/ ha was related to the planting date of 28 Feb. Yield of the first planting date was 42% and 574% higher than the planting dates of 29 March (1204 kg/ha) and 29 April (254 kg/ha), respectively. The total yield of cotton on the date of 29 March was 374% higher than the date of 29 April. The highest percentage of early maturity was related to the first planting date, which was not significantly different from the second and third planting date. There was no significant difference in different dates in terms of early maturity. In terms of mean boll weight, the first planting date had a higher boll weight of 11.5 and 87.6% than the second and third planting dates, but the difference between the date of the first and second crops was not significant in terms of boll weight, but The difference between these two planting dates and the third planting date was statistically significant on boll weight. The number of bolls per plant on the date of the first crop was 35 and 147% higher than the date of the second and third planting date, respectively, while the date of the second planting date had 83% more bolls than the date of the third planting date. There was no significant difference between treatments in terms of lint percentage but the second planting date had a higher lint percentage. Among irrigation water quality treatments, the yield of irrigation treatment with Karun water and intermittent irrigation with Karun water and drainage (combined) were not significantly different. Karun water irrigation had 12% higher yield than drainage irrigation, while the yield of irrigation with Karun water was only 6% higher than combined irrigation, this difference was not statistically significant. Among cotton cultivars, the highest yield with 1159 kg /ha was related to Golestan cultivar, which was 16.8% higher than Shayan cultivar. Shayan cultivar is one of the cultivars in which high temperature caused the flowers to dry out. The reason for the decrease in yield of Khorshid and Shayan cultivars was more withering and falling flowers at higher temperatures than Golestan cultivar. Golestan cultivar was more tolerant to salinity and heat stress than the other two cultivars. For this reason, it had more yield than Khorshid and Shayan cultivars and it seems to be a suitable cultivar for Khozestan. The effect of irrigation water quality treatments on fiber quality properties was not significant so that the highest strength with 26.84 was related to the date of the first planting (Feb.28), which did not differ significantly from the date of the second planting (March 29).. The effect of planting date on fiber strength at the level of 1% was significant. There was a significant difference between cotton cultivars in terms of strength and micronair at the 5% level. Shayan cultivar had the highest strength compared to the other two cultivars. The fiber strength of Golestan and Khorshid cultivars was statistically the same. Among cotton cultivars, Shayan and Golestan cultivars were significantly different from Khorshid cultivar at 5% level and had the lowest micronair. According to the results of this study, the first planting date on Feb 28 and intermittent irrigation with Karun water and drainage (combined) and Golestan cultivar is recommended for Khuzestan region.

Cotton is one of the most important fiber plants in Iran which needs more production for national fiber sufficiency goal. Its cropping area in Iran is now about 140,000 ha in which 95.3% is irrigated; rainfed cotton is growing only in Khorasan, Golestan and Mazandaran. Planting date and nutrition management and their interactions are amongst the most important determinants of crop yield. 

Field experiment in 2016 in the fields of Cotton Research Center of Golestan province in Hashem Abad split plot factorial in a randomized complete block design was conducted. Treatments include the planting date as the main factor, cultivar (Latif and Golestan) and nitrogen (three levels: desirable, a third desirable and without fertilizer) as sub plots. The first planting date in the traits (TDM, LAI, CGR and RGR) was superior to the second planting date. Among the cultivars, Golestan cultivar showed a better response to Latif cultivar at zero fertilizer level and 160 kg ha-1 nitrogen fertilizer. 

TDM variation and LAI of cotton cultivars during the growing season were three stages. The first stage, the phase of presentation, in which the TDM variations continued up to 55 and 61 days after planting and the rate of changes in the LAI, respectively, was 55 and 43 days after planting in the first and second planting dates. TDM accumulation changes up to 109 and 96 days, the LAI was about 88 and 96 days, the RGR was 55 and 61 days, and the CGR was 88 and 96 days after planting in the first and second plantings increased linearly. Maximum RGR and CGR were observed at cultivar Golestan cultivar at zero and 160 kg ha-1 in first planting date.

In general, first planting date (29 June) in comparison with the second planting date (12 July) caused higher DM production, LAI, RGR and vegetative growth and Golestan cultivar had better performance than Latif cultivar at 0 and 160 khNha-1. The maximum RGR at these two fertilizer level in Golestan cultivar was recorded at the first planting date which caused a significant difference for the time reaching maximum LAI.

Cotton or white gold is the most important and the oldest fibrous plant that is suitable for cultivation in arid and semi-arid regions. Among industrial plants, cotton has a special position. Not only cotton is one of the most important fibrous plants in view of fiber production, but also its seeds, which contain oil and protein, play a major role in providing edible oils and animal feed. Due to increasing need of society for cotton plant products and the importance of cotton in the global market and industries, it is very important to remove barriers to the continuous development of the cultivation of this product. Considering the importance of cotton in crop rotation and the sever reduction of cotton cultivation in recent years, it is necessary to use new approaches to increase the cultivation area, production amount and to reduce the production cost of this strategic crop. One of the strategies for developing the area under cotton cultivation is delayed cultivation as transplanting, which increases yield, early maturity and water use efficiency. Proper irrigation scheduling plays a very important role in delayed cultivations. In order to determine the physical and chemical properties of the soil in the study area, soil samples were taken from a depth of 0 to 30 and 30 to 60 cm and were analyzed in the laboratory. Fertilizer recommendation was done on the bases of soil test. In this experiment, the percentage of saturation moisture, electrical conductivity, acidity of saturated paste was determined and soil texture was measured by hydrometric method. Therefore, an experimental design of factorial strip plot, with three replications, was carried out in the Hashemabad cotton research station, in 2020. Irrigation methods of tape and furrow were as main factor. Cultivation methods of direct and transplanting as sub-factor and sub-sub factor was irrigation intervals after 70, 105, 140 mm cumulative evaporation from the pan, and irrigation quantities of 0, 50, 75, 100, 125% of the evaporated water from the pan. The treatment of 105 mm cumulative evaporation from the pan is usually 14 days, depending on the region. While the treatment of 70 mm means irrigating as soon as possible during 8 days. In addition, the treatment of irrigation after 140 mm of cumulative evaporation from the evaporation pan, ie once every 20 days, means that irrigation leads to plant stress. It should be noted that irrigation with less than 50% of the evaporated water from the pan can reduce the yield and is not applicable to the furrow irrigation method in the field, due to water not reaching the end of the field. In addition, irrigation with more than 125% of water evaporated from the pan is not highly recommended. The results showed that irrigation method had no effect on yield and yield components, but transplanting method had higher yield, early maturity, boll weight and water use efficiency at rates of 14, 180, 4.8 and 11.3% compared with direct method, respectively. Among the irrigation interval treatments, the irrigation after 105 mm evaporation from the pan had higher yield, boll weight and water use efficiency than the 70 and 140 mm treatments; So, that the yield of this treatment was 8.8 and 16.6% higher than the 70 and 140 mm treatments. While, water use efficiency of 105 mm treatment was 9% higher than 140 mm. In fact, cotton is a plant that reacts a lot to the amount and frequency of irrigation. It means irrigation management, and the balance between reproductive and vegetative growth is regulated by irrigation management. Excessive irrigation not only prevents increased yield, but also reduces yield and water use efficiency. Different irrigation water quantities had no effect on yield but on yield components had significant effect. The highest water use efficiency was related to 50% irrigation water, which was 19.6%, 43% and 69.8% higher than 75, 100 and 125% irrigation water, respectively. Irrigation quantity of more than 50% does not significantly increase yield but increases water use efficiency. Finally, the best treatment was transplanting method with an irrigation interval of 105 mm evaporation from the pan and 50% irrigation water of cotton increases. Also, transplanting cultivation increased yield compared to direct cultivation. Although it is not economically viable, it is recommended if the price of cotton increases.

Cotton as one of important crop products in Iran has special role and needs to increase its production to achieve self-sufficiency. The correct methods of crop management, including planting date are in order to determine the most appropriate growth conditions to increase yield and maximize productivity of the growing environment. Planting date of cotton is very important due to environmental limitations and coincides the sensitive period of cotton with severe summer heat and cultivation of two crops and early and late cold at the beginning and end of the season. The objective of this study was to obtain the best planting date in view of cotton high yield and increasing of water use efficiency.

In this study, 35 year (1984-2018) statistical data of Hashem Abad Meteorological Synoptic Station of Gorgan (precipitation, maximum and minimum temperatures, daily solar radiation) entered into the weather and product calibration model (SSM-Crop) and defines 11 planting date scenarios in the weather and product calibration model (SSM-Crop) (13 and 23 April, 3,13 and 23 May, 2, 12 and 22 June, 2, 11 and 22 July) was evaluated cotton yield changes and water use efficiency as well as its statistical characteristics during different years with different climatic conditions.

The results of predicted yield and water use efficiency in climate and crop model (SSM‌‌-Crop) showed that by delaying in cotton planting date, average cotton yield decreased but based on t-test Student results, there was no significant difference on cotton yield at the level of 5% in planting dates of related to scenarios of 23 April, 3 and 13 May. There was an increasing trend for average water use efficiency from 13 April to 23 May scenarios and then, from the 23 May to the 22 July scenario, was decreasing trend so that the highest and the lowest values were 10.07 and 1.75, related to 23 May to the 22 July scenario, respectively.

Cotton is a plant that planting date can play an effective role in yield and water use efficiency, but the best planting date regarding to calibrated climate and crop model was obtained from 5 May to 21 May. Delaying in planting date was not recommended so farmers Due to reduction in average cotton yield and water use efficiency. Because of delaying and cultivation of two crops during year in most farming fields of Gorgan. transplanting method can be recommend for obtaining of higher yield and optimum use of water in cotton.

One of the basic elements of water resources management and increasing agricultural productivity is the optimal use of (water) resources. The water footprint index is one of the new approaches used for this purpose. In this study, the water footprint approach was used to optimize the cultivation pattern of crops in different climates of Iran. For this purpose, 11 crops were selected in six different climates of Iran and after calculating the water footprint of the cultivated crops, the RIS indicators and the actual blue water footprint (WFAblue) were evaluated. After evaluating and calculating the indicators, the TOPSIS optimization method was used to provide the optimal cultivation pattern. Results showed that among the proposed products, wheat, barley, alfalfa, cotton, and tobacco had the highest amount of green water footprint, of which the highest one was corresponded to the PH-C-W climate. However, the highest blue and gray water footprint are mainly related to rice, beans, cotton and tobacco, which is due to the high water consumption of these products (high water demand). Evaluation of the optimization model also showed that the most optimal crops for cultivation in the region were respectively corn with 39%, barley with 23%, potato with 20%, tomato with 7% and wheat with 1% priorities. The most undesirable crops for cultivation in the provinces of the country were respectively, tobacco, cotton, beans, rice, sugar beet and alfalfa.

Repeated tillage, in addition to the burning of post-harvest crop residues in recent decades, has caused various problems, including reduced soil fertility and increased soil water losses, resulting in reduced water use efficiency. To study the effects of type of tillage system and how to manage wheat residues on yield, and cotton water use efficiency, a field experiment was conducted in 2016 and 2017 in a randomized complete block design with four replications in Hashemabad cotton research station of Gorgan was executed. The tillage system consisted of four levels of tillage: no-tillage (NT), conventional tillage (CT), disk (DK), combinate (ComT), and crop residues management of wheat including three levels of complete removal of the remains (CRR), straw removal (SR), and preservation of residues (PR). According to the results, the average total yield in two years of the experiment was 1183 kg/ha in the land preparation with disk (DK) and complete removal of residues (CRR) up to 2563 kg/ha in the land preparation with combinates (ComT) and preservation of residues (PR) was variable. In all tillage systems, the highest yield is related to (PR) and (SR). (CRR) significantly reduced the yield compared with those treatments. Also, the effect of treatments on water use was very similar to their effect on total yield. The average water use efficiency of 0.33 kg / m 3 of water consumed in the treatment of CRR, in addition to conventional tillage (CT) up to 0.77 kg / m3 of water consumed in the treatment (PR) Also, planting with (ComT) was variable. In all soil tillage systems, water use efficiency in the removal of residues was significantly less than the (PR) and (SR). Besides, the results of this study clearly showed that: a) Regardless of the tillage systems, preservation of wheat residue in the soil after harvesting can significantly improve the yield and water use efficiency of cotton, and (b) among the tillage systems, in conventional tillage (CT) system, the lowest yield and water use efficiency are obtained.

Climate change is one of the most important environmental challenges that has a significant impact on basic resources, including water resources, so it is necessary to assess this phenomenon, agriculture and water resources. In this study, due to this importance, the simulation of climatic parameters with the general ocean circulation model GFDL-CM3 under two commonly used scenarios RCP4.5 and RCP8.5 in two time periods of 2021-2040 and 2041-2060 in six different climates of Iran has been investigated and Using its results, the prediction calculations of the water footprint of agricultural crops were performed in two components, blue water and green water footprints. For this purpose, 31 stations from all over Iran were selected and classified by UNESCO classification into six climate classes and then their 30-year meteorological statistics data are entered into the LARS-WG model. meteorological data were generated over the desired time periods. The results showed that during future periods the temperature in the study areas will increase from 0.5 ° C to 2.3 ° C and rainfall changes will increase from -16 mm to 100.2 mm. This causes changes in green and blue water footprints in different climates of Iran from -13.44% to 37.53% in green water footprint and -18.77% to 38.20% in blue water footprint, respectively. Among the climates studied, the two climates SA-K-W and PH-C-W will have the largest reduction in green water footprint and the highest increase in blue water footprint, and will be most affected by climate change and its consequences.

Considering the importance of cotton in crop rotation and the decreasing trend of its cultivation area in recent years, it is necessary to use efficient and optimized methods to increase the cultivation area and the amount of production of this strategic crop and to reduce its production costs. One of these methods is the delayed cotton cultivation of premature cultivars in the form of transplanting. Considering the important role of time management and irrigation in cotton cultivation, it is necessary to determine the optimal amount of water consumed by this plant in the delayed cultivation method. This research was carried out in a split plot design by randomized complete block design with three replications. Irrigation interval treatments (including irrigation after 70, 105 and 140 mm cumulative evaporation from the evaporation pan) as main plots and different irrigation water amounts (including 50, 75, 100 and 125% of evaporated water from the pan) as subplots were considered. The results showed that the treatment of irrigation after 105 mm evaporation from the pan had the highest yield, bolting percentage, water use efficiency and lint content, and yielded higher yields of 11 and 40% than 70 and 140 mm treatments, respectively. While 100% water treatment with 2016 kg/ha had the highest yield among irrigation depth treatments, the difference between treatments with 50 and 125% was not significant in 5% level in Duncan test. On the other hand, with increasing water depth, water use efficiency decreased, in such a way that 50% water treatment had the highest water use efficiency. Finally, according to the evaluation results of performance, yield components, and water use efficiency, the best treatment was irrigating after 105 mm evaporation from the pan with depth of 50%.

Cotton is a plant that responds to the amount of irrigation water and irrigation time, and due to lack of water in Golestan province, the need for optimal use of water unit is more than ever before. This will not be achieved except through modern methods of surface irrigation or irrigation under pressure and appropriate management of irrigation and increasing water use efficiency.

This experiment was conducted as a split plot design in a factorial design with three replications at Hashem Abad Cotton Research Station. Physical and chemical parameters of soil such as soil texture, bulk density, moisture content of crop capacity and wilting point, soil salinity and soil acidity before cultivation were measured by sampling from two depths of 0.25 to 25 cm and 25 to 50 cm. Farm fertilizer requirement was calculated according to the results of the experiments. The distance of cotton cultivation during the studied surface was considered the same. Before irrigation was done due to soil moisture content. Planting two cotton cultivars was done randomly. During the growing season and before the first irrigation, a single-hinged rainwater system was implemented. During irrigation period, irrigation was carried out based on the water requirement of Plot i5 and irrigation continued on the basis of the water requirement of this plot to reach the farm capacity. During the growth period, the symptoms and the indicators of yield components included plant growth measurements, first flowering time, time of the first product, etc., and finally the yield was recorded. Different amounts of irrigation water treatments including rain irrigation, irrigation over water requirement as main plots and treatments of different amounts of nitrogen fertilizer including 0, 33, 66 and 100 percent fertilizer recommendation as well as cotton cultivars were considered as subplots.

The results showed that the highest yield (4362 kg / ha) was related to 4I treatment and the lowest yield was obtained from rain fed (without irrigation) with 3379 kg / ha. The yield of I2, I3, I4, I5 and I6 treatments was 2,2, 16,7, 29,1, 8,1 and 15/7 percent, respectively, than rain fed (I1). Among fertilizer treatments, the highest yield was related to unfermented fertilizer application, which was significantly different with treatments of 66% and 100% fertilizer requirement. The lowest yield was 66% fertilizer requirement. In a research year (2012) due to suitable rainfall in the growing season, cotton plants were well-grown, and any excess water or nitrogen fertilizer accelerated vegetative growth which ultimately led to a decrease in reproductive growth and Subsequently, performance declined. In terms of precocious percentage, rain and I4 treatments were the earliest and the shortest treatments. Different amounts of nitrogen fertilizer had no effect on premature percentage. The highest number of bolls per plant was related to I5 and I6 treatments, which difference was significant with I1 and I2 treatments, but not significant with I3 and I4 treatments. The amount of nitrogen fertilizer application from 0% to 100% of fertilizer requirement did not have a significant effect on the number of bolls per plant.

The yield of Golestan cultivar was 17.9% higher than that of B-557. Water use efficiency in rainfed and irrigation treatments was 1.51 and 0.81 kg / m 3 / ha, respectively. B was 557 earlier than Golestan cultivar. Two cotton cultivars called Golestan and 557 B were identical in number of bolls per plant. It is recommended to select Golestan cultivar as a basic cultivar pattern. In rainfed overwrought years, an irrigation can be done or watering is done in supplementary form.

Considering the importance of cotton in crop rotation and the high reduction of cotton cultivation in recent years, it is necessary to use new approaches to increase the cultivation area, production amount and to reduce the production cost of this strategic crop. One of these strategies is the delayed cotton cultivation in the form of transplanting method by using earliness cultivars. This method can be used to plant cotton after wheat in a crop rotation and due to shortening of the growth period and without dealing with cold, an acceptable amount of crop can be obtained. Managing the time and amount of irrigation plays an important role in delayed plantings. In this regard, it is necessary to determine the optimal amount of water used by cotton in transplanting and conventional methods. This experiment was carried out in a split split plot design with three repetitions with transplanting and direct treatments as main plots, irrigation frequency including irrigation after 70, 105 and 140 mm cumulative evaporation from evaporation pan as subplot, and various water quantities including 50, 75, 100 and 125% of evaporation from the pan were considered as sub-sub plots. The results showed 38% increase of yield for transplanting method in comparison to direct cultivation, but this increase was not significant. Water use efficiency, earliness percentage and lint percentage in transplanting were 14%, 45% and 3.3% higher than direct planting, respectively. The highest yield, water use efficiency, earliness and lint percentage were related to irrigation frequency after 105 mm evaporation of the pan. The treatment of 50% of used water had higher yield, water use efficiency, and lint percentage than other treatments. Therefore, the best treatment was the transplanting method with 105 mm pan evaporation and 50% used water.

Deficit irrigation is a management strategy for increasing water productivity. The yield loss can be compensated by saving water consumption under deficit irrigation. Increasing water productivity is a key factor in removing the biggest challenge facing the agricultural sector in water-limited areas, which means less water production. In order to achieve this, awareness of the relationship between water and yield, known as production functions, can be of great help in this regard. An experiment was carried out on a plot of 96 × 30 × 30 m2 based on a plot in a factorial arrangement in three replications. The main treatments consisted of six main hydrothermal treatments (0%, 33%, 66%, 85% 100% and 125% water requirement) and sub-treatments including four levels of fertilization (0%, 33%, 66% and 100% fertilizer requirement), and two cultivars named Golestan and B 557. Furthermore, the irrigation planning based on soil moisture discharge ranged from 5% to 70%. In this experiment, single branch sprinkler irrigation system was used, therefore 144 plots (6 water × 4 fertilizers × 2 digits × 3 repeats) were, created on the sides of the pipeline. On each cropping line, 20 cm spacing on each row and at a row spacing of 75 cm were cultivated. For each plot, the dimensions were 2.5 × 2.3 m (2.5 m in the direction of irrigation, and 3 m along the irrigation line). Soil samples were collected from each depth of 0-5, 20- 20, 20-40 and 40-60 cm before each irrigation. The moisture content was determined by weighing method. Based on the physical properties of the soil (bulk density, percentage of moisture content in field capacity and wilting point), effective depth of root and field management (MAD) 60-70% (based on previous studies), the depth of irrigation water was calculated. 40% of N-fertilizer application was carried out prior to sowing and the remaining N-fertilizer was applied from flowering stage with first irrigation and based on different treatments. The irrigation time was determined by dividing the irrigation water depth by the intensity of the sprinklers. 6I treatment due to the close proximity to the sprinklers received the largest amount of water and treatment 1I received the lowest amount of water (rain) as it was situated outside of the spray nozzle radius. From the beginning of planting, the irrigation program was carried out according to the amount of soil moisture at the irrigation time of the 5I treatment (100% water requirement). Therefore, it is expected that treatment 6I has received water more than water requirement. The total amount of water received by each row of crops during the growth period was measured by placing a water collecting canal mounted on a tripod to a height of 1 meter. After irrigation, by using cylinders the depth of water collected in the cans was measured. Due to wind blowing during the day, irrigation was carried out at night, to maintain the uniformity of water distribution. The final harvesting operation was performed for all treatments and replicates on first and second of November. a relationship and the corresponding regression coefficients were obtained between the irrigated yield and the each cultivar and fertilizer level separately, . The quadratic relationship was determined between the yield and the applied water. The coefficients values of the quadratic equation of production function were calculated for each fertilizer application and cultivars and were showed in Tables 5 and 6. The yield functions of cotton cultivars versus applied water were in the form of a second-order quadratic with a downward contraction. Initially, the gradient of the graph was high and then its intensity decreased indicating that water efficiency is much higher in irrigation. In addition, by increasing the amount of irrigation, the amount of the product reached to the peak value, and since then, a yield reduction was observed as applied water amount increased owing chiefly to Nleaching. The sensitivity coefficients for Golestan cultivars and 557 B were calculated at four levels of fertilizer according to the Doorenbos and Kassam formula. The average sensitivity coefficient for Golestan and B-557 was 1.18 and 1.27, respectively. It can be concluded that the Golestan cultivar is less sensitive to water shortage as compared with B-557. These results can be used to optimize water use under water constraints.

Optimizing water use in cotton is one of the main ways to save water and achieve optimal yield. Therefore, in order to study the effect of planting system and irrigation on morphological characteristics and yield of two cotton cultivars, this research was conducted in Hashem Abad Cotton Research Station in Gorgan in 2016. This experiment was conducted as a split plot design in a completely randomized block design with four replications. Treatments were included irrigation levels in 4 levels (irrigation based on 0, 40, 80 and 120% evaporation from evaporation pan), cultivars in two levels (Latif and Golestan) and planting system in two levels (transplanting and direct). The results of the experiment showed that the number of monopedia and the size of the simpodia above the ground in the transplanting system was more than direct system. By increasing irrigation water, the number of simpodia, plant height, and the size of simodia and monopedia increased significantly but had no effect on the number of monopedia. Latif cultivar had higher plant height and simpodia size and simpodia size above the ground compared to Golestan cultivar, but the number of monopedia in Golestan was more than Latif. The two cotton cultivars were similar in terms of number of simpodia and monopedia size. Cotton yield in transplanting system was 24% higher than direct system but this difference was not significant. The yield of two cotton cultivars had no significant difference. By increase in irrigation water from 0 to 80% of water use, yield increased but yield in the treatment of 120% water use decreased so that the highest yield (2515 kg / ha) was related to 40% water use treatment, which had no significant difference with 80% treatments but had significant difference with 0 and 120% treatments. The interaction effect of planting system on irrigation was significant only on plant height and simpodia size but the interaction effect of planting system in cultivar on morphological parameters was not significant. The interaction effect of irrigation on cultivars was significant on all morphological parameters except simpodia size above the ground.

To investigate the effects of city sewage on yield and yield components and the contamination balance of heavy metals in Ray Zone, an experiment in form of randomized complete block design with four replications and 5 treatments: Includes Treated domestic wastewater (T1), untreated domestic wastewater raw sewage, (T2) irrigation with well water and treated wastewater as interlaced (T3), irrigation with well water and untreated wastewater as interlaced (T4) and Well water as a control (T5) was conducted. The study showed that the effect of treatments on yield and its components was significant and best yield performance was achieved from untreated city wastewater. A significant difference at 1% level of earliness was observed among the treatments that the highest percentage of earliness with 75/8% belonged to Control which well water was used and untreated city wastewater had the least percentage of earliness. Significant differences at 1% level of the amount of manganese, copper, iron, nickel, cadmium and lead in cotton seed was observed among treatments. This study showed that the effect of treatments on yield and yield components were effective and the best performance was obtained using untreated home wastewater. The reason is that in this type of wastewater have more nutrients that play an important role in the production of bolls numbers and the performance of final yield. In arid and semi-arid regions like Iran reuse of water can be a means to compensate for water shortages.

In order to investigate the effect of magnetic field and irrigation with different salinity levels on cotton seedling emergence, a study was conducted as factorial experiment in a randomized complete block design with three replications in the Kashmar Higher Education Institute during 2016. In this experiment, different levels of irrigation water salinity were considered i.e.0.5: (S1); 3: (S2); 7: (S3); 10: (S4); and 13: (S5) ds/m as a main plots and magnetic field (M1) and non-magnetic (M2) as sub-plots. Six Neodymium-iron-boron magnets with the power of 1500 mT and dimensions of 4×2×1 cm were used to produce magnetized water. were included Determination of percentage and duration of seedling emergence under irrigation by magnetic and no magnetic were evaluated parameters The results showed that by increasing of salinity, germination of cotton reduced so that the ratio of reduction were as 46, 60, 83 and 100 % for salinities treatments i.e. 3, 7, 10 and 13 ds/m, respectively, under non-magnetic condition and also under magnetic condition were at the rates of 21, 46, 36 and 50 %, respectively. According to the results, it was evident that more than 67 % of the buds were appeared in all salinity levels under magnetic conditions before the fourth day after the appearance of the first seedling, while for non-magnetic conditions were obtained sixth day for low salinity and for high salinity 15day after the appearance of the first seedling. The results showed that magnetic water effect was significant at 1 and 5% on number of seedling and accelerate germination time, respectively. Therefore, it can be conclude that magnetic effect was positive on the number of buds and accelerate germination time under various irrigation water salinities.

The goal of this study was to investigate the effect of salinity and amounts of irrigation water on yield and yield components green pepper (Capsicum annum) variety of green Hashemi in greenhouse conditions.The research was done based on factorial experiment in completely randomized design including three replications as pot planting in Gorgan University of Agricultural Sciences and Natural Resources.Irrigation water quality consist of five levels of salinity (0%, 10%, 20%, 30% and 40% of the mixing sea water and tap water) and the quantity of irrigation water consist of three levels (100%, 125% and 150% of water requirement were considered). Data were analyzed with SAS and the results showed that the effect of irrigation water quantities on length, diameter and length to diameter ratio of fruit was significant (P

Due to water deficit in Golestan, it is necessary to optimize use of water which means to find relation between water use and yield. For this reason, this experiment was conducted by sprinkler irrigation as line source. Six irrigation treatments as I1, I2, I3, I4, I5 and I6 is assumed in two hand of sprinkler line because of sprinkler water triangular distribution, so that I1 and I6 treatments received the highest and the lowest water, respectively and I2 treatment received as water requirement as. Three cotton cultivars of Sahel, Sepid and 818–312 were planted by 20 × 80 centimeter. Experimental design was strip split plot with three replications. The results showed that the highest yield was I3 treatment that with I4, I5 and I6 treatments in the first year and all treatments in the second year had significant difference. Sepid cultivar yield was 17.9 % higher than two cultivars in the first year and 15 % higher than Sahel cultivar in the second year. Difference between three cultivars on view of earliness was not significant and on view of boll weight in the first year was not significant but in the second years was significant. The highest boll weight belonged to I3 Treatment and also I6 Treatment was the highest earliness. Sahel cultivar during two years had the lowest micronairy. Treatment of I3, received on view of water use received 30% less water than water requirement. Ultimately, on view of yield, quality properties and less water use, the best irrigation treatment and cultivar were I3 treatment and Sepid cultivar.

Water is an important factor in crop production، and is of a high value in agricultural Engineering. Water shortage is the most restricting factor in irrigated areas. Because of quality and quality limitation، deficit irrigation research has a special value in water use optimization and determination of water depths indexes inirrigation strategy. Thus، a determination of the water-yield relationship is essential. This study was carried out in Gorgan region to evaluate the effects of water stress on yield and water use efficieny of soybean in six levels of irrigation (is1-is6) for Sepideh variety in six replications using line source sprinkler irrigation method. Yield function for was derived as (Y=-0. 0528x2+54. 907x-3073. 5، R2=0. 93). Under full iriigation، the sepide cultivar need 354. 9 mm of water to produce maximum yield of 10190 kg/ha. Maximum and minimum of water use efficiency were obtaibed 16. 0 and 35. 3 kg/ha. mm at IS1 and IS4، respectively. Average grain yield and number of pods per plant were increased by increasind water depth. Minimum of grain yield، number of pods per plant and thousand grain weight were obtained in Is1. FAO water stress index (Ky) was obtained 0. 94. Ky was derived 0. 92. The comparison between the ky of cultivated soybean cultivars at Golestan province showed that katool cultvar has the more suitable response to water deficit than sahar and G3 cultivars to increase yield and optimal use of limited water resources.

Since trickle irrigation system efficiency depends on the physical and hydraulic characteristics of the drippers and specially water application uniformity, therefore evaluation of drippers as the most important section of a trickle irrigation system will be very important to have an efficient irrigation system. The objective of present study was to measure discharge rates of three different kinds of emitters (including Siplast, Inline168 and Katif8) at four different pressure levels of 50, 100, 150 and 200 kPa to assess the hydraulic performances, calculating the coefficient of manufacturing variation, water distribution uniformity of emitters and emitter discharge exponent, in order to establish the emitter´s flow rate sensitivity to pressure and comparing the results to the manufactures´ specifications. Based on results, Katif8 was classified as pressure compensating and inline168 and Siplast were classified as non-compensating pressure as expected. All three emitters distributed water uniformly at all operating pressures. Results indicated that designing trickle irrigation specially relationship between discharge and pressure should be based on reliable test data, not on manufacturer´s supplied data.

The objective of deficit irrigation is to increase water use efficiency by reducing of water quantity or wave off further irrigations that have not necessary. Cotton plant is sensitive to irrigation timing and quantity through different growth stages. The field trail was conducted at Hashemabad Cotton Research Station (Gorgan) to determine water consumption and cotton sensitivity to deficit irrigation at different growth stages during years 2004, 2005 and 2006. The study was carried out in a split plot design with three replications. Treatments of deficit irrigation in different growth stages were contained: deficit irrigation in flowering stage(I1), deficit irrigation in peak flowering stage(I2), deficit irrigation in boll formation stage(I3), deficit irrigation in flowering, peak flowering and boll formation stages(I4), deficit irrigation in flowering and peak flowering stages(I5), deficit irrigation in flowering and boll formation stages (I6) and deficit irrigation in peak flowering and boll formation stages (I7) as main plots and irrigation water quantities of 0% (q1), 35 % (q2), 70 % (q3) and 100% (q4) water requirement as subplots. Data from combined three years analyses showed that there were significant differences (R<0.01) among years with respect to yield, earliness percentage, boll weight and boll number per plant. Through different growth stages, deficit irrigation treatments showed significantly different yield but did not showed significantly difference earliness percentage, boll weight and boll number per plant. Irrigation treatments I7, I2, and I3 had the highest yield over 3 years. The lowest yield was found in I4 and I5. In summery, flowering and peak flowering stages can be considered the most sensitive growth stages with respect to water deficit. Irrigation water quantities were significantly different with respect to yield, earliness percentage, boll weight and boll number per plant. Treatment of 70% of water requirement(q3) had higher water use efficiency at rate of 16.7%, less water use at rate of 18.4% and 4.7% yield reduction than full irrigation (q4), so it can be applied as best treatment.

Compaction is applied by an external force on the soil and its result is decreasing soil macro porosity and increasing soil bulk density. One of the main important parameter in soil compaction is mechanization in agriculture and travelling in the fields. Compaction with decreasing in soil infiltration, percentage of stable aggregates and decreasing soil porosity limits the developing of roots, infiltration and decreasing of water in the soil and finally decreases crop yield. In order to study of the effect of C and L shape subsoiler on water consumption and quantitative and qualitative characteristics of cotton, an experiment was conducted in Hashem Ababd of Gorgan in silt-clay-loam soil for two years. This study carried out in split plot arrangement based on randomised complete block design with three replications. Two methods of subsoiling (parallel and perpendicular to row plant) were taken as a main plot and the form of subsoiler (L shape, C shape and moldboard as testimonial) were assigned to sub plot. C and L shape Subsoilers decrease the soil penetration resistance significantly which this decreasing was more in C shape subsoiler. the results showed that none of the treatments, subsoilers, the methods of subsoiling and their reciprocal effects, did not affect on cotton yield in the first year. However, the continuity of the second year subsoiling affected significantly the cotton yield. The C shape subsoiler in perpendicular to row plant had more cotton yield in compare with other treatments. Despite the lack of significant cotton yield increase, The use of subsoiler could be explained in economic terms with respect to the increased yield. The fibres quality was not affected by the treatments. Most water consumption in this study in first and second year was achieved by L shape subsoiler with 5740 and 4163 m3 ha-1, respectively.