نشریه مدیریت آب در کشاورزی
سال ششم شماره 2 (پیاپی 12، پاییز و زمستان 1398)

Due to the severe shortage of water in recent years and the implementation of agricultural policy in the agricultural sector, the use of drip irrigation in most Iranian plants has been implemented or under research and development. Due to technical characteristics of drip irrigation method, the irrigation efficiency in this method is more than other irrigation methods. Although drip irrigation is very effective in irrigation methods, but with the increasing expansion of drip irrigation in the country, the areas susceptible to the implementation of the system are limited and there may be restrictions on the implementation of drip irrigation systems in some areas. Therefore, in some cases it is necessary to predict the implementation of drip irrigation systems in some cases, such as changing the surface irrigation method to drip irrigation in the old trees, changing the root trees in the cause of some problems caused by pests..., etc. The purpose of this study was to investigate the capabilities, advantages and limitations of deep drip irrigation systems to make farmers and propagators based on a comprehensive knowledge of the system.

Increasing the production of agricultural products and income of farmers is one of the important goals of agricultural sector policy makers. But the limitations of water resources in this sector are facing serious challenges and, as a result of water resource management, has led the agricultural sector to cope with the use of alternative sources of water, especially saline waters, for the continuation of agricultural activities, because with existing knowledge, climatic conditions change are almost impossible to improve hydrological conditions. But by changing the managerial attitude on how to use the available water resources and using the rational use of salt water as an irrigation water source, while increasing agricultural production, the competitiveness of non-water can be reduced. In this paper, based on empirical evidence and internal and external scientific findings, the feasibility of using saline water resources in agricultural activities is discussed. The results indicate that water consumption of drainage water, considered qualitatively as non-consumable water in agriculture, can have a positive and determining effect on increasing the production and income of some agricultural products such as wheat, cotton, and forage plants, while they can provide conservation areas for fresh water resources and cultivation area development. For example, irrigation of wheat with drainage water (12 dS/m) in Golestan province (Iran) reduced wheat yield by only about 10%. Also, the composition of drainage water with a salinity of 20 dS/m with non-saline water (1 dS/m) is 50%, although the yield is reduced from 4000 kg to about 3600 kg ha-1, but by saving 50 percent of freshwater resources, a new opportunity will be created for sustainability of water resources, or to expand cultivation and increase production. Main challenges are also expressed in applying saline water resources, and suggestions for policy and proper application of these resources in the agricultural sector are presented.

Due to the issue of water scarcity and drought in Iran, agriculture water management is essential. Agriculture water management requires a policy of correct and efficient use of water, and the smart irrigation system is a suitable and optimal way to use water properly. For this purpose, a moisture sensor device was designed and constructed in February and March 2019 to determine the appropriate time to stop irrigation in furrow irrigation. Testing the device in the laboratory and its application in the Farm of the Campus of Agriculture and Natural Resources, University of Tehran, (Mohammad Shahr), Iran, from April to July 2019. The purpose of this study was to evaluate the performance of smart sensor of soil moisture to determine the optimum depth of installation and recording of soil moisture at 10, 30 and 50 cm depths and different length ratios in furrow irrigation. Initially, calibration of the device was carried out on field soil and based on the obtained validation, the device was transferred to the field. To achieve the goals of optimum depth of installation and optimum length, 36-meter furrows with a distance of 0.75 meters were created in the field. Sensitive lengths in furrows with 0.5L, 0.75L, and 0.85L ratios were selected as the starting points. The results showed that in the calibration and validation phase the R2 value (coefficient of determination) were 0.93 and 0.95, respectively, and in the calibration and validation stage the value of NRMSE (Normal Root Mean Square Error) was 80 and 13.81%, that indicating good model training in the calibration stage. Also, the average RE (Relative Error) parameter in estimating soil moisture was 2.74%, indicating high accuracy of the device in estimating soil moisture. The results also showed that if the device was installed at a depth of 30 cm from the soil surface of the furrow and at 75% from the beginning of the field, the depth and runoff losses would be minimal and irrigation adequacy would be best compared to other depths and lengths. It is expected that with optimal water consumption and timely interruption of irrigation, deep losses and runoff will be avoided and with low water consumption, the productivity of crops will increase.

Stomatal conductance is one of the important indices to assess water deficit stress in plants. To evaluate stomatal conductance in corn leaves for scheduling irrigation, an experiment was conducted at East Azarbaijan Research Center for Agriculture and Natural Resources. The experiments were as Randomly Complete Blocks with three replications and with treatments of a: full irrigation, b: deficit irrigation from stages of 6-7 leaves to the end of ripening with full irrigation at flowering stage, c: deficit irrigation from stages of 6-7 leaves to the end of ripening with full irrigation at dough stage. The stomatal dimensions were determined by copy method. Stomatal conductance was measured along a leaf with different distances, at different leaves of a plant and at before and after irrigation events by a porometer. Results showed that the stomatal along a leaf and at leaves of a plant had a variable value. So that the stomatal conductance increased with increasing distance from petiole to leaf tip and with an increasing leaves number for soil surface to the canopy. The stomatal conductance changes along the leaf and its variability in leaves numbers were modeled as Logistic functions. The temperature variability along leaf was modeled as Sinusoidal function. Results also showed that the stomatal conductance from irrigation treatments were different. The stomatal conductance from two days after irrigation were similar and averaged 0.31 ms-1. The suitable time for irrigation and its cutoff were at stomatal conductance of 0.21 and 0.33 ms-1.

Providing appropriate solutions for the management of water productivity and consumption of sugarcane crop production requires a thorough understanding of the strengths, weaknesses, opportunities, and threats of the crop production system. In this regard, the present study seeks to strategically analyze the water productivity management of sugarcane crop production in Khuzestan province with emphasis on its strengths, weaknesses, opportunities and threats. Research methodology is classified into descriptive and analytical methods in which questionnaire-based surveys, interviews and SWOT analytical tools are used to identify and analyze the strategic factors of internal environment (strengths and weaknesses) and external environment (opportunities and threats). Sugar cane experts are used. According to the results of the study, mechanization of sugarcane cultivation and production pattern with 0.862 final weight was identified as the most important strength. Inadequate awareness of irrigation workers about water, soil and plant issues with a final score of 0.744 with the most significant weakness, the existence of researchers and specialists in the sugar cane production industry with a final weight of 0.864, the most important opportunity and inappropriate utilization management with a final score of 0.555 to They were identified as the most important threat. In addition, competitive strategy with final weight of internal factors of 2.745 and external weight of external factors of 3.104 has been adopted as the most important strategy in the management of water input productivity in sugarcane production in Khuzestan province.

Proper and efficient use of water in the agricultural sector is of great importance. Therefore, it is not possible to achieve development without preventing water loss and utilizing new technologies. One way to achieve this aim is to replace the tape irrigation system Instead furrow irrigation method. For this purpose, two irrigation methods and water requirement for peanut yield and water use productivity in a split plot experiment were conducted in a completely randomized block design with three replications in 2015 in Guilan province. The main treatment consisted of two levels of surface irrigation (furrow) and tape and sub-treatment consisted of 40, 60, 80 and 100% water requirement management. The results showed that the highest biological yield, pod and seed yield under tape irrigation and 100% water requirement were 13894, 5029 and 3273 kg ha-1, respectively. The highest water use productivity based on biological yield was observed in diameter irrigation conditions at 100 and 75% of water requirement with average of 2.12 kg / m3. The highest water use productivity was based on pod and seed yield under tape irrigation and 100% water requirement with mean of 0.77 and 0.5 kg m-3, respectively. Due to the peanut water requirement and the limited rainfall and water resources at flowering time, the least water should be used to the maximum. Therefore, tape irrigation can be used as an efficient and useful tool for optimizing peanut moisture.

Various methods of fertilization and irrigation in furrow method should be evaluated and managed in order to increase efficiency, reduce evaporation, leaching and deep percolation. One of these deficit furrow irrigation methods is partial root zone drying. So, the purpose of this study was to investigate the distribution and absorption of water and nitrate, nitrate leaching and water use efficiency of Every Furrow Irrigation method (EFI), variable Alternate Furrow Irrigation method (AFI) and Fixed alternate Furrow Irrigation method (FFI). For this purpose, corn (S.C. 704) was planted on early May 2016. In order to apply different irrigation methods, 12 furrows with a width of 70 cm and a length of 40 m were selected and divided into three treatments. Samplings with three replications were made at 1, 3, 5 and 9 days intervals after each irrigation at 10, 30, 50 and 70 cm below the surface of soil in dry and wet furrow. Results showed that the amount of water and nitrate absorption in EFI, AFI and FFI methods were 0.198, 0.178 and 0.143 (m3-water/m3-soil×30day) and 0.0022, 0.0018 and 0.0011 (mg/kg), respectively. Also in FFI method nitrate accumulation was occurred under the dry furrow. Water application efficiency in EFI, AFI and FFI methods was 51%, 81% and 77%, respectively. Finally, the AFI method with the least amount of leaching was chosen as the preferred method.

This research was used from climate information such as average humidity, average wind speed, soil temperature and salinity of different soil depths (5, 10, 20, 30, 50, and 100 centimeters) in 10 years (2008-2017). The purpose of this study was to investigate the relationship between climate parameters and soil salinity fluctuations. For this purpose, rice soil salinity data were used which were previously measured. In both seasons of rice cultivation (conducted in one of the nurseries of Alborz province), salinity fluctuations at different depths of soil were recorded over a period of five to seven days, and soil salinity required for the purposes of this study was obtained, and then with the required meteorological data, the research was done. Also, Hurst test to find enough variance of the data to analyze the time series trend, and Mann-Kendal, spearman, and multivariate regression tests were applied for data analysis. The results showed that all parameters of the study based on the Hurst coefficient bigger than 0.5, had a significant variance for time series analysis. The results of Mann-Kendal and spearman tests showed that in surface soil layers (5 and 10 cm) after 10 years period, the soil salinity had a descending trend. However, both tests had an increasing trend in deeper layers (20, 30, 50 and 100 cm) and at depths of 50 and 100 cm observed the significantly increasing trend at a 5% level. Result of the multivariate regression test illustrated that the temperature in depth of 5 cm and average relative humidity (each 16%) and average speed of 60% had the most and the least effect, respectively on the soil salinity in the mentioned soil depth. Also, in four depths of six depths, the temperature in depth of 5 cm was the most effect on soil salinity of different soil depths. As a general result, in areas where the conditions of this present study, cultivation of plants with surface roots is possible because salinity fluctuations in the surface layers are low and it does not pose a threat to the plant under cultivation but crop cultivation with deep roots is limited because salinity fluctuations is an increasing trend that should be addressed so that soil salinity does not have a detrimental effect on plant yield.

In this research, to evaluate the Zero inertia model in SIRMOD and WinSRFR software, data from the advance time, recession time and runoff volume were obtained from conventional furrow irrigation (CFI), fixed alternative furrow irrigation (FFI) and alternate furrow irrigation (AFI). The simulation results were used with the help of the relative error index (RE) for the infiltrated water volume and the root means square error (RMSE) index for prediction of advance and recession time. To determine soil permeability coefficients were used of the model SIPAR-ID, Multi-level optimization, Two-point method of Elliott-Walker and IPARM. The results of the CFI method in SIRMOD software, the Elliott-Walker two-point method with RMSE equal to 1.81 and in the WinSRFR software, the multi-level optimization model with RMSE equal to 1.66 The results had the highest accuracy in predicting advance times. The simulation of the advance and recession time of the FFI method indicated that the best value of the RMSE index for using the SIPAR-ID model in SIRMOD and WinSRFR software was 2.42 and 2.41 minutes, respectively. The results showed that in the AFI method, using the IPARM model in SIRMOD software and the multi-level optimization model with WinSRFR software, the best accuracy was achieved with RMSE 1.61 and 1.24 min, respectively, at advance times, respectively. As a general result, it can be stated that according to the similar prediction of two SIRMOD and WinSRFR software, it is recommended to simulate, design and evaluate irrigation systems in the case of accurate estimation of influence coefficients.

The rapid growth of the world's population and the increasing occurrence of droughts due to climate change and human actions have made available water available for agriculture worldwide reduced. The sharp decline in water resources has made agriculture section, as the largest consumer of water resources, involve to serious drought challenge. Given the need to food and increasing crop yields as well as water scarcity in the country, increasing yields per unit area should be achieved by saving water consumption as well as increasing water productivity. In Iran, the current productivity of sugar beet is about 0.6 kg of sugar per m-3 of water. According to the major goals of water use productivity improvement plans, it is expected that in the year 2025, one kg of sugar will be produced per m-3 of water. To achieve the goals of the plan, it is necessary, besides to increase the yield of sugar to about 10 t.ha-1, make the water consumption closer to actual water requirement by managing the water resources and using water reduction strategies. This paper shows the issues related to the causes of low water productivity in sugar beet farming and presents a management package to reduce irrigation water use and increase water use productivity resulting from numerous field studies in different regions of the country. Suggested items are: 1- Early seeding of sugar beet, 2- Change in sugar beet planting pattern, 3- Deficient irrigation in growth stages of drought-tolerate, 4- use of pressure irrigation systems, 5- development of autumn sugar beet cultivation, 6- Use of recommended Varieties for water deficit conditions, 7 -Sugar beet planting using transplanting system, and 8 - Sugar beet seeding after harvest or last irrigation of autumn cereals. In this article, after introducing the management package, their effectiveness as well as guidelines for the requirements developed in the field are presented.

Saffron is a valuable and highly economical plant that will reduce its yield if not harvested in a timely manner. The research was conducted because of lack of sufficient manpower at harvest time, differences in weather conditions and price fluctuations at the time of purchase of the product. Irrigation treatments were irrigation on the conventional time (15 days before harvest), T1, irrigation with 15 days delayed T2 and irrigation delayed by 30 days. In the mean study, the yield and forage content were statistically significant at 5% probability level, but no significant differences were observed between the number of flowers and corm weight. The highest and lowest values for yield and number of flowers were observed in T3 and control treatments, respectively. The highest fresh weight and fresh fodder for T2 treatment with 7.6 grams and 88.3 g / m2 were obtained according to the results. The results showed that analysis of variance of yield and forage yield at 5% probability level (P <0.05) were statistically significant. There were no significant differences between the number of flowers per square meter and the weight of the bunches. In general, it can be stated that irrigation treatment with 30 days delay increases the yield of saffron.

Implement of pressurized irrigation systems within the farms are not possible in some provinces of Iran, due to high cost of energy supply, evaporation and wind-drift losses, salinity conditions and ownership patterns. Therefore, the appropriate option is the application of low- pressure irrigation systems. The low- pressure system is a series of tubes that are supported by the canal, water tank or pumping station and distributes water to the farm ditches with a low pressure. The history, advantages and challenges of the application of low-pressure irrigation systems and some extension approaches are mentioned in this study. The major advantages can be referred to the reducing water conveyance time, increasing the irrigation efficiency, decreasing energy losses, preventing pollution of groundwater resources, controlling human diseases and reducing the cost of maintenance and applications. The challenges of application of low- pressure irrigation systems include the more complication relative to open irrigation systems, the inability of designer engineers to design and implement systems, the need for higher hydraulic height, and impossibility for monitoring water flow in the distribution system. It highlighted the importance of factors of design and implementation of low - pressure systems such soil and water characteristics; cultivation pattern and water requirements; irrigation management; design of border, furrows and basins dimensions; design of conveyance lines and pools; design of gated pipes; irrigation scheduling; maintenance procedure; cost of project implementation; economic evaluation; project management ; dimensional design; and design criteria for surface irrigation methods

A challenge of sustainable development is related to agriculture, food security, and conservation of water and soil resource, under the current crop production paradigm. Increasing crop yields often have negative environmental impacts. Soil salinization and sodication are major environmental hazards that limit agricultural potential and are closely related to agricultural unsuitable management and water resources overexploitation, especially in arid climates. In this study, we investigated the negative impacts of saline and sodic irrigation water on soil properties that it is necessary to study the factors affecting the degradation of soil structure to implement proper land management and we intended to help the farm producer or landowner to understand the fundamental differences between these two problems. Samples of clay loam and sandy loam soils were treated in 5 wetting and drying periods with different types of water quality (which combinate different levels of EC and SAR). Soil water content of samples was achieved at soil matric suctions of 0, 10, 20, 40, 60, 100, 300, 1000, 2000, 4000 and 15000 cm. Also, dispersible clay and saturated hydraulic conductivity were determined. Results showed that increasing of SAR caused dispersion of clay and saturated hydraulic conductivity was decreased with increasing of dispersed clay. Increasing SAR caused some macropores and mesopores changed to micropores and as result enhanced water retention especially at high matric suctions. Water retention capacity was enhanced by increasing in water EC as that flocculated soil particles and created new soil pores.

The scarcities of fresh water resources for agriculture production on the one hand and low cost establishment and energy supply and easy maintenance on the other hand, has led researchers to conduct many studies about increasing surface irrigation efficiency. In this study, effect of deficit irrigation at the furrow end on furrow irrigation performance indicators and effect of soil moisture profile on silage corn yield (biomass) were investigated in Karaj, Iran, in 2014. Four treatments (100% irrigation: full irrigation, 75% irrigation: 25% deficit irrigation, 50% irrigation: 50% deficit irrigation and 25% irrigation: 75% deficit irrigation at the furrow end) were considered. Deficit irrigation increased application efficiency. Runoff was as a main irrigation water loss due to short furrow and high slope. Deficit irrigation increased non-uniformity of moisture profile and crop production along the furrow. The most non-uniformity of crop yield along the furrow was observed in the 75% deficit irrigation treatment. Crop yield was greater at the upstream than at the downstream of experimental furrows. There was a direct relationship between crop yield and storage efficiency. The treatment with 25% deficit irrigation at the furrow end was identified as the best treatment regarding water saving and low reduction of crop yield.

The village, after the family, is the most important center of life, the foundation of society and the center of agricultural activity and production. Our country also relies on agricultural products and agriculture creates a value or a basic right for the villagers. Therefore, the villagers are entitled to the use of agricultural water first and foremost and in the first place. Therefore, this research has been done by descriptive-analytical method and data gathering by documentary method and in some cases it has been surveyed with the aim of whether the rights of villagers and peasants in agricultural water have a scientific, rational, impartial and equitable status. The overall conclusion of the study is that in the present situation, the rights of peasants in agricultural water suffer from conflicting principles and policies and do not support its clear customary and religious laws. As a result, the rights of the villagers to agricultural water are not systematic and targeted. The national agricultural water project in Barmayoun village is also in line with the government's future policy and election promises. The solution of this article is firstly to create a comprehensive law on the system of rural agricultural water, and then to democratize the Iranian administrative system, namely the election, supervision and dismissal of various local administrations and heads by the elite community of local people.