جستجوی مقالات مرتبط با کلیدواژه « سند ملی آب » در نشریات گروه « آب و خاک »

Irrigation planning is one of the management strategies, which is based on determining the exact water requirement. The lysimetric method is the most accurate method of determining the water requirement of the plant, but due to the high cost and the need for high technical knowledge, it cannot be used anywhere. The basis for determining the water requirement in the Ardabil Plain is the use of NETWAT software output information, which is known as the National Water Document of Iran. This software calculates the water requirement using the Penman-Monteith FAO model. The output of this software due to the need to update climate information, not introducing the exact range of plains, ignoring sub-climates in some plains and catchments (including Ardabil Plain), and not considering some important crops in the plain (lack of potato water requirement in Ardabil Plain) and the creation of new databases in recent years, should be reconsidered. 

This study in Ardabil Plain and water requirement of the dominant crop pattern including wheat, barley, potato, alfalfa, and bean crops was calculated by the Penman-Monteith method and CROPWAT software. To calculate the net irrigation requirement, first, the evapotranspiration potential of the plain was obtained using climatic information from three stations Ardabil, Abi Biglou, and Namin. Then, the effective rainfall of the plain was extracted by the information from Ardabil, Abybeigloo, Namin, Koozeh Topraghi, Gilande, and Samian rain gauge stations. Required information on plain soil was prepared using 22 points in the plain. In the last step of the information preparation phase, the characteristics of the cropping pattern plants were defined using field measurements, local experiments, and FAO publication No. 56. The cropping pattern (91.4% of the cultivated area of Ardabil Plain) included wheat, barley, potatoes, alfalfa, and beans, which according to the five-year statistics ending in 2021, the cultivated area of these crops was 18,300 (32.6%), 10300 (19.4%), 15700 (28%), 5200 (9.2%) and 1200 (2.2%) hectares. After preparing the case information, the water requirement was calculated for each of the wheat, barley, potato, alfalfa and bean products in each of the soil sampling points in 10-day periods during the growing season. Based on the point information obtained, a zoning map of net irrigation needs in the Ardabil Plain was prepared.

Based on the obtained point information, a zoning map of net irrigation needs in the Ardabil Plain was prepared. The results showed that the zoning of the net need for irrigation divides the Ardabil Plain into three separate parts in this regard. The northern part and the southern part are divided into high consumption, the eastern and southeastern parts are low consumption, and the western part and parts of the center are divided into medium consumption. In addition, according to the zoning results, the average, minimum, and maximum net irrigation needs of the crops were calculated. For the wheat crop, the average, minimum, and maximum net irrigation requirements were 164, 314, and 259 mm, respectively. For the barley crop, the average, minimum, and maximum net irrigation requirements were 110, 255, and 205 mm, respectively. For the potato crop, the average, minimum, and maximum net irrigation requirements were calculated as 325, 613, and 484 mm, respectively. In addition, for alfalfa and bean crops, the mean, minimum, and maximum net irrigation requirements were estimated at 425, 872, and 670 mm and 337, 637, and 497 mm, respectively.

The results showed that if the average of the whole plain is used for wheat, barley, potato, alfalfa, and bean crops, instead of point or regional information, about 18, 20, 21, 23, and 22% deficit irrigation, respectively, and in Low consumption sector accounts for about 58, 86, 49, 58, and 48% of excess irrigation. Also, the results showed that using the output numbers of NETWAT software will cause wrong water management in Ardabil Plain. Therefore, using the results of the National Water Document (NETWAT) will lead to incorrect water management due to the problems mentioned. That is if the results of the national document are used as the basis for determining the water requirement in the Ardabil Plain, compared to the minimum and maximum numbers obtained from this research, about 32 and 38 MCM will occur in the exceeding irrigated and deficit irrigated plains, respectively (without considering the impact potato crop due to not calculating its water requirement in the national water document for Ardabil Plain). Considering climate change and also the development of different databases, it is suggested to use up-to-date information for water requirement calculations. Also, considering that the Ardabil Plain is divided into three separate parts in terms of the net need for irrigation, therefore it is recommended that instead of using one number as the consumption in the whole plain, from point or regional information obtained from this research for wheat, barley, Use potatoes, alfalfa and beans.

Considering the importance of water consumption management in the agricultural sector, in this research, the application water efficiency and the water consumption volume in wheat fields of Semnan province were investigated. The volume of inflow, outflow, soil moisture before and after irrigation and the depth of root were measured and based on them, the values of application water efficiency was determined. The results showed that there is the most water losses in the first irrigation and the application water efficiency varies according to several factors such as farm management, depth, length and slope of furrows, physical properties of the soil. The average values of application water efficiency in the surface irrigation method were estimated at 30.6%. Inattention to the characteristics of the soil, the slope of the land, the depth and length of the furrows, the lack of proper leveling and inappropriate timing of irrigation with the plant's water requirements, and the low flow rate entering the furrows have caused an increase in water losses in the fields. The average volume of water consumption in Shahrood, Semnan, Damghan and Garmsar was 7700.7, 6628.3, 5875.4 and 7890.8 m3/ha, respectively. Comparing the calculated water requirement with the volume of irrigation water showed the application of deficit irrigation in the wheat fields of Semnan and Damghan. Also, the results showed that the calculated water requirement was higher than the values in the national water document. According to the area under wheat cultivation in the province, for every one percent increase in application irrigation efficiency, about 793,000 m3/ha of water will be saved.

About three quarters of the country's sweet lime orchards are located in Fars province. Having sufficient information on the amount of irrigation water and water productivity of these gardens can lead to better management of water resources and increase water productivity. In this research, the water productivity and the amount of water given in 60 sweet lime orchards in six regions of Fars province were measured during 2021. Among the selected orchards, due to differences in irrigation management, soil salinity and other factors, the volume of irrigation water varied from about 10000 to 24000 m3/ha per year. The average total volume of irrigation water was 14712 m3/ha. In terms of the regional average, the lowest and highest amount of irrigation water was related to Ghir-Karzin and Darab regions with 13023 and 17079 m3/ha per year, respectively. The productivity of irrigation water in selected gardens was between 0.71 and 2.23 kg/m3 and on average 1.40 kg/m3. Comparing the volume of irrigation water with the gross water requirement showed that in the year of conducting the research, these differences were statistically significant in Lar and Darab regions. In general, the average difference between the volume of irrigation water and the annual gross water requirement in the province was 569 m3/ha, which was not statistically significant. But on average, the volume of irrigation water was 2288 m3/ha more than the long-term gross water requirement, which was a significant difference. Therefore, it is necessary to apply irrigation scheduling and accurately determine the required water to increase the productivity of sweet lime orchards in Fars province.

Fars province is one of the prominent provinces in the country in the production of oranges and tangerines. Having sufficient information on the volume of irrigation water and water productivity in orange and tangerine orchards can lead to better management of water resources and increase water productivity. In this research, water productivity and irrigation water volume were measured in 60 orange and tangerine orchards in three regions of Fars province during the crop year 2019. Among the selected orchards, due to differences in irrigation management, the state of water resources and soil conditions, the volume of irrigation water varied from about 8800 to 24700 m3/ha/yr. The average total volume of irrigation water in orange and tangerine orchards was 15388 and 15093 m3/ha, respectively. The average volume of applied water, which is the sum of effective irrigation and rainfall, was 18289 and 17867 m3/ha, respectively. The average fruit yield for orange and tangerine orchards was estimated as 18.4 and 20.8 t/ha, respectively. The productivity of irrigation water in selected orchards was between 0.45 and 3.03 kg/m3 and on average for orange and tangerine it was 1.30 and 1.44 kg/m3 respectively. Comparing the volume of irrigation water with the gross water requirement showed that in the year of conducting the research, the volume of irrigation water was on average 4400 m3/ha or in other words 41% more than the required water. The average difference in the volume of irrigation water with the long-term gross water requirement was about 4000 m3/ha. Considering the area of orange and tangerine orchards in the three regions of Darab, Jahrom and Kazeroon, the amount of water saved will be 46, 8 and 14 Mm3/yr, respectively.

About 34% of the lemon produced in the country is obtained from Fars province. This province, like many parts of the country, is one of the arid and semi-arid regions, and water management is of particular importance in it. In order to better plan and manage water resources and increase the amount of crops and water productivity of farms and gardens, sufficient information should be available on the amount of water used in different crops. Considering the importance of lemon fruit in Fars province and conducting little research on the amount of irrigation water for this product in the country, it can be useful to investigate this index and the water productivity of this product in the Fars province.

In this project, the water productivity and the amount of irrigation water given by gardeners for lemon production during one year (2021) were measured without providing technical or expert advice to the gardeners. The location of the research was the seven most important cities in Fars province in terms of lemon cultivation area, including Qhir-Karzin, Jahorm, Darab, Lar, Kazerun, Farashband and Mohr. In each city, 10 gardens and a total of 70 gardens were selected for data collection and monitoring. The desired gardens in the cities were identified and selected with the help of experts from the agricultural jihad organizations of the provinces. The studied lemon orchards were selected in such a way as to cover various factors such as irrigation method, soil texture, variety and quality of irrigation water. The yield was obtained in three consecutive years and their average was used in the analysis. The selected gardens were all equipped with drip irrigation system. The amount of discharge from the water source was measured by calibrated meter in each of the selected gardens three times a year. After determining the flow rate of water entering the orchard, by carefully monitoring the irrigation program of the orchard and also measuring the area under cultivation, the volume of irrigation water for lemon trees in each of the selected orchards was measured. The amount of evapotranspiration of lemon trees in each region was calculated using the meteorological data of the nearest station to the project implementation area in the last 10 years and the year of conducting the research using the Penman-Montieth method. The values of net required water of lemon were also obtained from the National Water Document. The gross required water of gardens was obtained and compared with the irrigation water volume of gardens by t-test. Variance analysis was used to investigate yield changes, irrigation water volume and water productivity in lemon production in the target cities.

Among the selected orchards, due to differences in irrigation management, soil salinity and other factors, the amount of irrigation water volume varied from about 6000 to 21000 m3/ha/yr. The average total volume of irrigation water was 13376 m3/ha. In terms of regional average, the lowest and highest amount of irrigation water volume was related to Jahrom and Darab with 10030 and 16433 m3/ha, respectively. The average total volume of applied water, in which the amount of effective rainfall is added to the volume of irrigation water, was estimated to be 14407 m3/ha/yr. The range of changes in the volume of applied water in gardens varied from about 7000 to 22000 m3/ha. Therefore, it can be said that the contribution of rainfall in the year of conducting the research was on average about 100 mm or 1000 m3/ha. In terms of volume of applied water, the highest and lowest amount belonged to Kazerun and Jahorm cities with 18799 and 10768 m3/ha, respectively. Irrigation water productivity in selected orchards ranged from 0.69 to 3.21 kg/m3 and averaged 1.52 kg/m3. Comparing the volume of irrigation water with the gross water requirement in different areas showed that in some regions over-irrigation and in some deficit irrigation was done. But in general, the average difference between the volume of irrigation water and the annual gross water requirement was 255 m3/ha, which was not statistically significant. However, the volume of irrigation water at the rate of 1735 m3/ha was more than 11640 m3/ha of long-term gross water requirement, which was statistically significant at the level of 1%. Therefore, it is necessary to apply irrigation scheduling and determine the exact water requirement to increase the productivity of the lemon orchards in Fars province.

Volumetric delivery of water by installing smart water meters on the agricultural wells could be an effective action for proper use of water and increase the water productivity. In recent years, the smart water meters were used at Arsenjan plain in Fars province for volumetric water delivery.

In this study, the applied water and the water productivity in some of the Arsenjan plain farms and gardens were evaluated. Twelve farms were selected for each of the three products; winter wheat, tomato and pomegranate. Well discharge, crop yield, volume of applied water was measured using smart meters. The actual values were also measured. The values of irrigation water productivity and total water productivity was calculated. The differences between applied water and some water requirement scenarios were compared using t-test.

Results showed that the values of applied water and discharge in the smart meters were 21 and 25 percent less than the actual measured values, respectively. Therefore, the performance accuracy of the studied smart water meters was low. The average irrigation water productivity of wheat, tomato and pomegranate was 0.93, 7.75 and 1.44 kg/m3, respectively. The average applied water in the studied farms and gardens were 43 percent more than the required values estimated by Penman-Montieth method. Finally, it was suggested that in order to improve the performance of smart meters, the calibration of these meters should be considered more carefully.

Increasing irrigation efficiency and reducing water losses in gardens is necessary due to the severe shortage of water resources in the country. In order to increase the irrigation systems efficiency it is necessary to evaluate them. For this purpose, 6 gardens with basin irrigation system were selected. The amount of irrigation water volume, depth of root development, yield, application efficiency (early, mid and late of the growing season) and water productivity were determined. Also, the water requirement was calculated by the Penman Monteith method using meteorological data (recent ten years) and compared with the values provided in the National Water Document. In apricot orchards, the average application efficiency varied from 43.3 to 58.4 percent (average of 49.7 percent) and in vineyards from 41.7 to 61.9 percent (51.4 percent on average). Deep percolation was the major portion of irrigation water losses in apricot and grape gardens by 49.7 and 51.4%, respectively. The average water productivity of these products was 0.78 and 5.2 kg.m3 respectively. The results showed that in gardens where land leveling and water supply of the trees were well done, irrigation efficiency and water productivity were significantly increased. Comparing the computational water requirement with the volume of irrigation water shows the imposition of deficit irrigation in these gardens. The results also showed that the computational water requirement was much higher than the values mentioned in the National Water Document, which highlights the need to update the National Water Document.

Permissible working hours of agricultural wells in the Neyshabour plain was determined equal 4120 hours by regional water authority of Khorasan-e-Razavi. This research was conducted to introduce method of working hours of agricultural wells in the Khorasan-e-Razavi province (case study of Neyshabour plain) and analyse effective parameters on working time of wells. For this purpose, the area of agronomy and horticulture crops was obtained for the years of 2001 to 2010. Water requirement of these crops was extracted from the water national document. Working hours of wells for every months would be calculated by deviding gross irrigation requirement to average hydromodul of three maximum months. The calculations to assess the effect of sowing pattern was done separately in two phases, for all crops pattern and for major crops pattern. In the thirth and forth phases, the effect of annual variation of water requirement and irrigation hydromodul were assessed on the working hours of Neyshabour plain wells. The results showed that instead of using all crops pattern, it is possible to use just major crops in calculating of working hours of wells. Annual variation of sowing pattern and water requirement in the Neyshabour plain have significant effect (95% confidence) on working hours of wells. By suppose the constant area under crops in the Neyshabour plain, adjust in calculating of working hours of wells was done using measured hydromodul in the region. In adjusted method, the annual working hours showed increase averagely 440 (11%) hours in compare to permissible working hours of Neyshabour plain (4120 hours). This variety in working hours of wells cause to be near to existence and realy conditions of the Neyshabour plain. In an agronomy year, it is possible to have an acceptable forcasting for working hours of regional wells by determining the sowing area of wheat and barley.