Knowing and determining the water productivity is the first step to improve it. The aim of this research is to determine the water productivity of potato plants in hot, moderate and cold climates of Kermanshah province. In the mentioned climates, Qasr-e-Shirin, Kermanshah and Sonqor cities, which had the largest area under potato cultivation, were selected as the areas for conducting this research. For this purpose, 35 farms were selected under the conditions of farmers in 2021-2022. The total volume of irrigation water of each of the selected farms was measured during the growing season. Effective precipitation was determined using the USDA equation. The amount of water consumed by farms was also calculated from the total amount of irrigation water and effective precipitation. After harvesting the crop and determining the yield of potatoes by dividing the amount of yield by the amount of water consumed, the water productivity of the selected farms was determined. SPSS software and ANOVA analysis of variance were used for statistical analysis of the results. The results showed that the average volume of potato irrigation water in the sprinkler method in Qasr-e-Shirin, Kermanshah and Sonqor cities was 7507, 7186, and 6739 m3 ha-1, respectively, and their average water consumption was 8002, 7246, and 6783 m3 ha-1, respectively. The average yield of potatoes in these cities was 24100, 35500 and 36100 kg ha-1, respectively. Therefore, the average water productivity of potatoes in these cities was 3.4, 4.9 and 5.7 kg m-3, respectively. Therefore, the results showed that the water productivity of potatoes in Qasr-e-Shirin city is 30%, and 40% lower than in Kermanshah and Sonqor cities, respectively, and the most important reasons are the lower yield and the larger volume of irrigation water and potato water consumption in this city. Therefore, it is possible to increase yield and reduce water consumption and finally increase the water productivity of potato by managing agronomic and breeding, and training farmers in order to reduce water consumption in this city.

Wheat, with the scientific name Triticum aestivum L., is the world's first agricultural product, which is consumed by 35% of the world's population as the main food source. The cultivation area of this crop in the world is 219153830 ha, of which about 48% of it is under irrigation. The area of wheat cultivation in Iran is 6908545 ha, and about 34.3% of it is under irrigation. The area of irrigated wheat crop in Kermanshah is about 102236 ha. Based on the statistics of the crop year 2021-2022, Kermanshah province ranks sixth, fourth and third in the country in terms of the amount of cultivated area, production and yield of water wheat. Wheat plant is one of the main and major agricultural products of Kermanshah province and it is cultivated under irrigation in a large area of their lands. Therefore, determining wheat physical water productivity is an important indicator in wheat production planning. Considering the increase in population, climate changes, lack of water resources, and the increasing need for wheat production and food supply, it is necessary to improve the wheat water productivity. To improve water productivity, the first step is to know and determine its amount. Unfortunately, there is no accurate information about its amount in Kermanshah province, and only information related to the results of research projects in certain conditions is available, which cannot be generalized due to the difference between those conditions and the conditions of farmers' fields. The purpose of this research is to determine the water productivity of wheat crops in cold, moderate and hot climates of Kermanshah province.

Kermanshah province is located in the geographical position of 45° 25ʹ to 48° 6ʹ East longitude and 33° 41ʹ to 35° 17ʹ North latitude. Kermanshah province with an area of 24434.25 km2 covers about 1.5% of the country's area and its average height is 1200 m above sea level. This province generally has three climates: cold, moderate and hot. Based on the statistics of the agricultural year of 2020-2021of the Organization of Agricultural Jahad of Kermanshah province, and in the mentioned climates, Sonqor, Kermanshah and Sarpol Zahab cities respectively have the largest area under wheat cultivation and were selected as the research areas. To carry out the current research, 34 farms were selected under the conditions of farmers and during the growing season, the total volume of irrigation water of each farm was measured. The effective precipitation was determined using the data of the closest synoptic meteorological station to the selected farms and the USDA relationship. The volume of water consumed by each selected farm during the growing season was also calculated from the sum of the total volume of irrigation water and effective precipitation. After harvesting the crop and determining the yield of wheat by dividing it by the amount of water consumed, the amount of physical water productivity in each of the farms was determined. Then, the data obtained in the studied cities were statistically analyzed using SPSS software.

The results showed that the average total volume of irrigation water measured in Sonqor, Kermanshah and Sarpol Zahab cities was 5204, 5795, and 4236 m3 ha-1, respectively, and the average volume of wheat water consumption was 6297, 7737, and 5844 m3 ha-1, respectively. Therefore, the total volume of wheat irrigation water in Sarpol Zahab city was 19% and 27% less than in Sonqor and Kermanshah cities, respectively, due to the short duration of the wheat growth period and growth in the cool months of the year. This causes the amount of wheat water consumption volume in this city to be 7 and 24% less than the two cities of Sonqor and Kermanshah, respectively. The average yield of wheat in the mentioned cities was 5799, 7082 and 4937 kg ha-1, respectively. The average physical water productivity of wheat in the mentioned cities was 0.97, 0.95 and 0.86 kg m-3, respectively. Therefore, the results showed that the amount of physical water productivity of wheat in Sarpol Zahab city was lower than the other two cities, and the most important reason was the low yield of wheat in this city.

In this research, the values of the total volume of irrigation water, the volume of wheat water consumption and the physical water productivity of wheat in cold, moderate and hot climates of Kermanshah province were determined. The results generally showed that the total volume of irrigation water and the volume of wheat water consumption in the hot climate of the province were less than in the cold and moderate climates of the province due to the short growth period of wheat and the growth of this plant in the cool months of the year. Therefore, due to the smaller amount of the volume of wheat water consumption in hot climate, it was expected that the physical water productivity of wheat in this climate would be higher than the other two climates of the province. However, due to the lower yield of wheat in the hot climates, this did not happen and the physical water productivity of wheat in the hot climate of Kermanshah province was lower than the two cold and moderate climates of the province. Therefore, it is possible to increase the yield and finally increase the physical water productivity of wheat by managing agronomic and breeding in this city.

To calculate the index and optimal depths of crop water use, and maximizing the profit under deficit irrigation practices, this study was performed using a split plot design. In this experiment three cultivars of early maturing corns (301, 303 and 315) were set as the main treatments with 3 replications, while the irrigation levels were considered to be the minor treatments. A line source irrigation method (after Hanks) with 6 irrigation levels on both sides of the line was used. In this research, three sub-functions such as yield Y(w), cost C(w), and benefit B(w) were developed initially. Then, the optimal depths of irrigation were extracted from these functions. The results indicated that: a) although the complete irrigation had the maximum yield, however, the marginal net profit was not maximum because of the cost rise, b) with deficit irrigation under land restriction conditions and aiming to maximize the use of unit land, the optimized water depth for all cultivars was 3% less than the complete irrigation, and c) using deficit irrigation under water limitations and aiming to maximize the use of unit volume of water, the optimized irrigation depth would be 19% less than the complete irrigation practices. Also, the results showed that the net benefit was the same for the equivalent depth and the maximum water depth; therefore, it is logical to use the equivalent depth. Meanwhile, applying 17.5% deficit irrigation for cultivar 301, 20.4% for cultivar 303 and 19.1% for cultivar 315, the highest earning return (Rials per m3 of water) will be 1011.2, 1206.1 and 1543.6 Rials, respectively. It can be concluded that with the savings of water under deficit irrigation practices, the planting area would increase and ultimately the marginal net profit increases substantially. Also, the most net profit among the cultivars was obtained for cultivar 315.

Due to lack of accurately measured data on crop water consumption in Hormozgan province, the FAO- estimated crop water requirement data are used in most irrigation projects, without their prior assessment in terms of compliance and consistency with the region, which in turn, it may cause water loss or water stress to the plant. Thus, the present research was carried out to evaluate the FAO method precision in estimating canola water consumption in Hormozgan province. Accordingly, first, a lysimeter was installed in the center of a 4-ha ground area. Next, in and around the test site, the canola cultivar (Hyula-401) was cultivated and its water consumption was measured weekly by water balance equation. Climatic parameters such as air temperature, relative humidity, wind speed, sunshine, and rainfall were measured at the meteorological station located on the site and using them, reference crop evapotranspiration was calculated by FAO-56 Penman-Monteith Equation. Then, via multiplying it by the crop coefficient (Kc) identified according to the FAO guidelines, canola water consumption was calculated in weekly periods and compared with values obtained from lysimeter. Finally, the results showed that although the FAO method has a good accuracy in estimating the seasonal water use of the plant in the test area, if the purpose of the planning is irrigation at the farm level, this method could overestimate weekly water consumption from 0.06 to 1.5 mm day-1. Therefore, it is recommended to modify the estimated water consumption by the FAO method using the regression equation proposed in this research.

About two-thirds of rivers, lakes and groundwater are applied for agricultural production in the world. Same as other countries, a significant fraction of surface and groundwater resources are used in agricultural sector in Iran. Water balance at country scale is the origin of estimation of applied water as agricultural consumption. The variability of annual precipitation is as the origin of the components of water balance in hydrological cycle, caused changeability in the water consumption of agricultural sector which are important reasons for estimating and re-estimating consumptive water in agricultural sector. Therefore, in this study, consumptive water of agricultural sector was analyzed based on long term (50 years) and short term (current 7 years) measured data for precipitation with the method of water balance in hydrological cycle in the country. Results revealed that average annual precipitation were 249±53 and 206±33 mm for two long and short studied periods, and the consumption water in agricultural sector were 67 ±18 and 83±6 km3 for long (50 years) and short (7 years) periods for non-modified conditions. The modified consumption water for the short period was 75±6 MCM.Results revealed that for the long period, the water consumption in agricultural sector was 0.50 of renewable water in the country. The outstanding of this study was up to date estimating of the water consumption in agricultural sector and its analysis. But applying water balance method for this purpose has some substantial limitations and non-reliable simplifications. Therefore suitable experiments are needed to reliably the results.

Determination the water consumption and water productivity of different products can be a great help to the decision-making of water and agriculture officials. Therefore, the present study was conducted to measure water consumption and the yield of bean at 25 fields managed by farmers in Azna, Aligudarz and Selseleh counties in Lorestan province. Thus, the volume of water consumed for bean were measured in the selected fields with different irrigation methods and various water sources without interfering with their irrigation scheduling during the growing season. The amount of water consumption under different irrigation systems varied from 8669 to 19312 m3.ha-1. The average of water consumption and water productivity in sprinkler and surface irrigation systems were 9735, 16161 m3.ha-1 and 0.33 and 0.16 kg .m-3, respectively. Therefore, it can be said that sprinkler irrigation compare to surface irrigation system increased the water productivity and reduced water consumption about 106 and 39.8 percent, respectively. The average of irrigation efficiency in both sprinkler and surface irrigation systems determined about 67.5% and 35.7%, respectively. The results of comparing the average volume of water consumption, water productivity and irrigation efficiency with t-test showed a significant difference between sprinkler and surface irrigation systems. Comparison of average water requirement by using t-test showed that The average computational water requirement differs significantly from the national average water document by 6720 and 6994 m3.ha-1, respectively. Investigation of correlation coefficients showed indirect changes in water consumption with irrigation efficiency and water productivity. However, the relationship between irrigation efficiency and crop yield has been consistent and positive with water productivity

Increasing crop production per unit volume of water consumption requires recognizing the most dependent variable in drip irrigation to the volume of water consumption and also identifying the most important variables independent of water productivity in surface and subsurface drip irrigation for optimal use of available water resources. The present research was carried out in Behbahan Agricultural Research Station during four cropping seasons (2013-2017) on a Kabkab date variety. Experimental treatments include the amount of water in the subsurface drip irrigation method based on two levels of 75% and 100% water requirement and in surface drip irrigation based on 100% water demand. Data were analyzed using a randomized complete block design with three replications. The results of the analysis of variance of the mean of different irrigation treatments in quantitative traits showed that the effect of irrigation was significant at the level of 1% in terms of cluster weight index, fruit weight, and fruit flesh to kernel weight ratio. The results of regression analysis of variance showed that in the dependent variable of cluster weight, the consumption water volume explained 19.1% (R2 = 0.191) of the fluctuations of the dependent variable (cluster weight). Among all the studied variables, the volume of water consumption explained the most significant changes in date cluster drying. Fruit moisture with t (2.096) and equivalent beta coefficient (0.046) had a significant positive effect on water productivity at the level of 5%. The results of the Pearson correlation coefficient showed that the effect of yield on changes in water productivity was much greater than the volume of water consumed so the yield caused significant changes in water productivity. While the effect of water consumption on water productivity was not significant.

Increasing water use efficiency is one of the cases to arrivance to the stability production. In order to estimation and comparison of water use efficiency among crop species including corn، safflower، sesame، and medicinal species including hemp، marsh mallow، white mallow. An experiment was conducted during 2009 growing seasons in the Agriculture research Station Ferdowsi of Mashhad. The experiments was white mallow established as a completely randomized block design with three replication and six treatments included six crop corn، safflower، sesame as crop plant and hemp، marsh mallow، white mallow as medicinal crop. Results showed that the treatments had significant effect (p≤0/01). The highest value of water use efficiency were obtained in Corn by 1/84 g per kilogram by 6770 m3 watered requirement and lowest value obtained in white mallow by 0/04 g per kilogram by 7530 m3 watered requirement. However the highest value of harvest index was 41/57 percent in Marsh mallow and lowest value was 9/2 percent in marsh mallow.

Electricity generation and water consumption are intertwined. With increasing population and increasing economic development, the need for energy increases and as a result, water consumption issues in energy systems will become much more complex. Most power generation technologies require water for cooling, steam turbines and power plants. The amount of water required for different types of power generation technologies is different. This study examines the amount of water consumed by Iran's combined cycle power plants and identifies the close relationship between the amount of electricity production and the amount of water used to generate electricity and helps to improve the conditions for environmental protection by managing water and energy consumption. In this study, library studies and similar studies in Iran and the world were conducted and the coefficients and methods for calculating the amount of water consumed were extracted. The amount of water consumption of each power plant was obtained by multiplying the amount of electricity generation and WCF related to the dry cooling system and the type of power plant using natural gas fuel. Finally, the data obtained from the calculations were compared with the actual data of the water consumption in the electricity generation process (demin water). Studies showed that the use of international water consumption coefficients estimates very different results compared to real data. Therefore, the use of water consumption coefficients for Iran can not be used.