Journal of Water and Irrigation Management
Year:2019 | Volume:8 | Issue:2 |Papers Count:10

Considering the extent of salinity in soils of Iran, abiotic stresses such as salinity are serious threat to agricultural production of medicinal plants. For this purpose, the effect of different irrigation regimes and salinity on some properties of leave of quinoa cv. Titicaca. This research was conducted as a factorial experiment in the basis of randomize complete design with 3 replications in Gorgan University of Agricultural Sciences and Natural Resources during 2016. In this research, deficit irrigation levels consist of 3 levels (50, 75 and 100 percent of water requirements calculated by evaporation pan class A) and salinity factors consist of 5 levels (0, 10, 20, 30 and 40 percent of the mixing sea water and tap water). The result showed that different salinity levels on Leaf area index, leaf length, leaf width, petiole length and leaf relative water content were highly significant (P>0. 01), but different irrigation regimes and interaction of salinity and irrigation regimes on chlorophyll (P>0. 05) and leaf relative water content (P>0. 01) were significant. Result of this study showed that increasing the amount of irrigation water and salinity levels significantly increasing and decreasing all studied characteristics, respectively. The results showed that increasing of salinity levels from 0 to 15 percent mixture of sea and tap water has resulted to redaction of grain yield to 2. 2 and percent, respectively.

The shallow groundwater can compensate a part of plants water requirement. In this investigation Lysimetric experiments were conducted to determine the contribution made by groundwater to the overall water requirements of (Stevia rebaudiana B. ). The plants were grown in 36 mini lysimeter (or pot), each having a diameter of 0. 40 m and packed with silty clay soil. The three replicate randomized complete block factorial experiments were carried out using different treatment combinations. Nine treatments were applied by maintaining groundwater, with an EC of 1, 2, 6 and 10 dS/m, at three different water table levels (0. 7, 0. 9 and 1. 20 m) with supplementary surface irrigation. The supplementary irrigation requirement for each treatment was applied by adding water (EC of 1 dS/m). The average percentage contribution from groundwater for the different treatments (1, 2, 6 and 10 dS/m) and water table depths (0. 7, 0. 9 and 1. 2 meter) as (66. 5, 57. 7, 45. 3) and (61. 5, 52. 7, 42. 1) and (59. 9, 49. 4, 41. 0) and (59. 0, 46. 6, 40. 1) percent of the average annual (Stevia Rebaudiana B. ) water requirement respectively. The main results showed that the shallow ground water with quality less than 2 dS/m can be used to compensate a most part of the annual plant water requirement.

In recent years, application of pressurized irrigation systems in palm fields has been increased. The objective of this study was to evaluate the irrigation systems and to determine the best system for date palm fields in Bushehr, Iran. The methodology of this study was defined in the form of water consumption measurement, evaluation of irrigation efficiency and providing a decision making model. In this study, the effective technical-executive criteria contributed 39. 1% in irrigation system selection, 21. 0% in economic criteria, 21. 0% in social criteria, 19. 9% in operation and maintenance criteria and 11. 0% in environmental criteria. According to the multi criteria decision-making model in Bushehr, the bubbler irrigation system was the most suitable system. Also, in some places of Bushehr provience where the bubbler irrigation system cannot be implemented, replacing the traditional flood irrigation system with alternate furrow irrigation system was the proper system. Evaluation results of the bubbler irrigation systems in Dashtestan district showed the lowest irrigation efficiency equal to 36. 6 percent and the average value equal to 56. 5 percent. The lowest and average irrigation efficiencies in Tangestan district were equal to 31. 4 and 57. 8 percent respectively. The lowest and average irrigation efficiencies in Jam district were equal to 40. 1 and 65. 2 percent, respectively.

Drought is one of the most important factors limiting crop growth and in most phases of plant growth effect is harmful and destructive. Therefore use of practice to reduce its adverse effect is very important. It seems that, through exogenous application of glycine betaine, plant resistance to drought stress can be increased. In order to investigate the effect of drought stress and glycine betaine foliar spraying on photosynthetic parameters of chickpea, a factorial experiment was conducted in a completely randomized block design with three replications in a research greenhouse of the Faculty of Agriculture of Lorestan University in 2017. Drought stress in four levels (control, 75, 50 and 25 of field capacity) and foliar spraying application of glycine betaine in three levels (0, 25 and 50 mM) were applied. The results showed that drought stress significant at 1% level of probability decreased photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, photosynthetic water use efficiency and carboxylation efficiency, but glycine betaine notably improved them. Glycine betaine application enhanced the photosynthesis in water-deficit experiencing plants, mostly due to a greater stomatal conductance and carboxylation efficiency of CO2 assimilation. It could be concluded that spraying glycine betaine (25 mM) improve photosynthetic parameters in drought conditions and induces more water stress tolerance in chickpea.

This study was conducted to compare the estimation methods of the reference Evapotranspiration for the methods based on solar radiation with FAO Penman Monteith for different climates to find the best model for each weather station and each climate in Iran. The evapotranspiration equations used in this research were Turc, modified Turc, Hargreaves, Makkink models, Priestley-Taylor, Jensen-Haise, McGuinness & Bordne, Jones & Ritchie, Irmak, Hansen, Doorenbos-Pruitt, Abtew, and tabari et all models. Meteorological data of 154 synoptic stations across the country on a daily basis was prepared from the country's Meteorological Agency for 15 years. The accuracy of the methods was evaluated using the statistical indexes. Among them are RMSE, MBE, R and t. The results showed that models of Hansen and modified Abtew were more applicable and Jones & Ritchie and Hargreavs had the less accuracy in arid climates. In semi-arid areas Irmak and Hansen methods had more accuracy. In Mediterranean areas Adjusted Turk and Makkink 2 were more accurate methods. In the semi-humid, humid and very humid areas the methods of Priestley-Taylor and Irmak presented more appropriate results. The methods of Jones & Ritchie and Doorenbos – Pruitt were the less accuracy in all climates.

Due to drought and water scarcity, the use of unconventional waters in agriculture, i. e. the outlet of urban wastewater treatment, has become an important water resource, recently. The aim of this study was to investigate the effects of irrigation with Khorramabad treated urban wastewater in Lorestan province on the accumulation of chemical elements such as nitrogen, potassium, phosphorus, and sodium in soil along with soil organic matter, pH and salinity in a pepper field. The experiment was conducted in the form of randomized complete blocks design with six treatments: T100: 100 percent wastewater, T75+25: 75 percent wastewater + 25 percent fresh water, T50+50: 50 percent wastewater + 50 percent fresh water, T25+75: 25 percent wastewater + 75 percent fresh water, T0+100: 100 percent fresh water, and T0+100+k: 100 percent fresh water containing fertilizers with three replications in the research greenhouse of faculty of agriculture, Lorestan University. Experimental results showed that the effects of treatments on the accumulation of phosphorus, potassium, sodium, organic matter, EC, and pH were significant at 1 percent level and nitrogen at 5 percent level. By increasing the percentage of wastewater in irrigation water (T100: 100 percent wastewater), to pre-planting soil the concentration of available phosphorus (59%), available potassium (20. 7%), total nitrogen(2. 28-fold), and organic matter (1. 1-fold) increased, and the pH (except T100 treatment) 7. 4% and EC 18% decreased. In addition, the findings of this study indicated that with the use of wastewater due to its nutrients which are required for the plants, it is possible to minimize the fertilizer consumption by a proper management plan.

Consideration to climate variables are the primary factors that controlling rainfed cultivation and the adaptation of the growing and reproductive period to the appropriate climate conditions provide through the sowing date. Therefore, the main objective of this research is to offer the time of the occurrence of water stress susceptible stages (flowering and milking) in order to achieve optimal yield in the main areas of rainfed wheat cultivation in Iran. Six western and northwest provinces of Iran are the first to sixth-largest in terms of area under cultivation and yield in rainfed wheat production, in this regard, it was used daily statistics of temperature and precipitation during (1998-2014) as well as soil texture data were used which had the appropriate coverage of the studied area (31 Stations). Firstly, it was offered a new definition of effective precipitation and determined sowing date and germination. Then, considering the degree-day of growth (1400-1700), the date of the beginning and the end of the flowering and milking stage was determined. The calculations were performed with SMADA software at three probability levels: 70, 80 and 90 percent, with choosing of the best statistical distribution. Accordingly, it was determined the time interval from 23 September to 27 October for germination and 2 periods between March 15th and April 15th and May 10th to June 10th for flowering and dying periods.

In order to investigation the root distribution and plant growth of Rosmarinus officinalis L., an experiment was conducted in a completely randomized design with three replications under using subsurface irrigation system in 2016. In this study treatments are full irrigation (FI), regulated deficit (RDI75 and RDI55) and partial root zone drying irrigation (PRD75 and PRD55). The results showed that deficit irrigation at 75 and 55 percent of full irrigation resulted in saving 17. 1 and 32. 6 percent water consumption respectively. Comparison of FI and PRD75 showed that dry weight, height of plants and number of shoots per plant decreased 5. 3, 9. 8 and 8. 9 percent respectively. However, proper development of root in PRD75 increased 12. 8 percent of water productivity, 7. 3 percent of root fresh weight, 2. 7 percent of root depth and 10. 7 percent of root volume. Therefore, considering the problems of water scarcity, it is possible to provide PRD75 as a superior treatment and a suitable strategy to cope with the water crisis, to move towards a sustainable agricultural system.

Evaluating the efficiency of empirical methods for determining of reference evapotranspiration is essential in order to determine plants water requirement. Therefore, in this this study, the meteorological data of 154 stations around the Iran country were used during the statistical period of 15 years (1999 to 2013). Potential evapotranspiration for all synoptic stations was computed using the computational methods based on air temperature, containing 17 methods. The results of different methods were compared to the result of the reference method (FAO-Penman-Monteith). The best and worst methods were selected based on different statistical indexes including regression coefficient, squared squares, mean error estimates and Jacobis criterion. The results showed that for dry climate, Hargreaves-M4, Hargreaves, Hargreaves-M2, Hargreaves-M1, Hammon 1961, Hamon 1963 and Hargreaves Samani were the most suitable methods, respectively. For semi-arid climate, the Hargreaves-M4, Hargreaves, Hamon 1963 and Hargreaves Samani methods were the most appropriate methods. In the Mediterranean climate, the Hargreaves-M4 and Hargreaves methods were the most appropriate methods. In the semi-humid climate condition, the Hargreaves-M4 and Hargreaves-M2 were selected as the most appropriate methods. In wet climates, Hargreaves-M4, Hargreaves-M2 and Hargreaves-M1 methods were the most suitable methods and in the very humid climates, the Hargreaves-M4, Hargreaves, Hargreaves-M1and Blanicril-4 were the most appropriate methods respectively. Moreover, the Schendel method also was selected as the worst method in all the above mentioned climates. Meanwhile, in the semi-arid climate, the lysimetric studies confirmed the selection of the best and worst methods for estimating temperature evapotranspiration.

Use of subsurface drip irrigation and absorbent material such aszeolite increase the moisture retention in soil. So, it has effective effects on crop yield and water use efficiency. In order to evaluate the study of the effect of dripper depth and zeolite amount on corn, this research was conducted in two crop seasons: the first one on March 2016 to June 2016 (T1) and the second one on July 2016 to November 2016 (T2) at research farm station in ShahidChamran university of Ahvaz as completely randomized block in split sprite block. In this study, two treatments consist of calsic zeolite in three levels (zero: Z0, 5%: Z1, and 10%: Z2) and implementing dripper in three depths (10cm: D1, 20cm: D2, and 30cm: D3) with three replications. The results showed that dripper depth had a significant effect on corn biomass, nitrogen percentage and protein percentage and zeolite amount had a significant effect on corn yield, biomass, nitrogen percentage and protein percentage (P-Value≤ 0. 05). The interaction effect of dripper depth and zeolite amount had a significant effect on leaf area index, nitrogen percentage and protein percentage (P-Value≤ 0. 05). The highest yield and water use productivity were observed in D3Z3, the highest biomass was found in D2Z3 and D3Z3. The interaction of all treatments showed that T2D3Z1, T1D3Z3, and T1D3Z2 had the highest yield and T1D2Z3 and T2D2Z3 had the highest biomass. Treatments D2Z3 had the highest protein percentage and D2Z3 and D3Z2 had the highest nitrogen percentage. Concluding the results, D3Z3 was the best treatment in the case of yield, water use productivity, biomass, and corn quality. So, it is recommended to use depth 30cm to implement the dripper and use 10% of zeolite for cultivating corn in Khuzistan.