Somayeh Shirzadi; Mostafa Mardani; Ali Shahnazari
Abstract
Water supply and demand Management plays an important role in the agricultural sector. In recent years, due to inadequate management of agricultural water distribution, agricultural lands in Tajan Irrigation and Drainage Networks are suffering from excessive use of groundwater and salinity. Therefore, ...
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Water supply and demand Management plays an important role in the agricultural sector. In recent years, due to inadequate management of agricultural water distribution, agricultural lands in Tajan Irrigation and Drainage Networks are suffering from excessive use of groundwater and salinity. Therefore, the purpose of this study was to investigate the sustainability of groundwater, water consumption, and distribution management in Tajan Irrigation and Drainage Network after implementing water-pricing policies and reducing available water of upstream lands. For this purpose, Positive Mathematical Programming model and the Asano sustainability index were used. The required data were collected from Agricultural Jihad Statistics, direct referral to Jihad-e-Agriculture Organization and Mazandaran Regional Water Company in years 2016 and 2017. The results showed that the situation of water resources in the region is not stable, while changing the cropping pattern and adopting different irrigation policies in the region will increase the sustainability of water resources from 0.45 to 0.27, which corresponds to changing from critical to good situation. The higher price policy for water up to 30% compared to the current conditions has little effect on irrigation water use. However, reducing available water of the upstream lands, in addition to reducing the amount of consumed water and managing its consumption, would improve the economic benefits of the network, with a minimum reduction in the upstream economic benefits. Therefore, in order to contribute to the sustainability of groundwater in the region, it is suggested that managers of the Tajan Network should adopt the policy of reducing available water to the upstream lands.
A GH; A SH; M R; H Z
Abstract
Deficit irrigation, as a limiting factor for growth, will affect physiological characteristics of plants. In order to investigate the effects of deficit irrigation on yield, chlorophyll fluorescence, dry weight of stems and leaves, and leaf area index of sunflower, this study was performed at the research ...
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Deficit irrigation, as a limiting factor for growth, will affect physiological characteristics of plants. In order to investigate the effects of deficit irrigation on yield, chlorophyll fluorescence, dry weight of stems and leaves, and leaf area index of sunflower, this study was performed at the research farm of Agriculture and Natural Resources University of, Sari, Iran, in 2013. The experimental treatments were arranged as randomized complete block design with three replications. The irrigation regimes consisted of full irrigation (FI), regulated deficit (DI75, DI55), and partial root-zone drying irrigation (PRD75, PRD55). The results indicated that the effect of irrigation treatments on yield, photosynthetic efficiency, maximum fluorescence (Fm), minimum fluorescence (Fo), leaf area index, shoot dry weight, leaf dry weight, and head dry weight was significant. Comparison showed that water stress significantly decreased grain yield, photosynthetic efficiency index and maximum fluorescence (Fm), whereas the minimum fluorescence (Fo) was increased. The maximum seed yield (5148 kg ha-1) was attained in full irrigation treatment and had no difference with PRD75 treatment. The maximum leaf area index at the end of the growing season was 4.3 and recorded in FI and had no difference with PRD75, DI75 and PRD55. Overall, treatment PRD75 is recommended since it reduced water consumption by 16.8 percent relative to FI treatment and had no significant difference with full irrigation treatments (FI) in terms of seed yield, quantum yield, and other growth parameters.
a darzi; m mirlatifi; a shahnazari; f ejlali; m mahdian
Abstract
Proper water management in paddy fields is the most important operations that plays a fundamental role in the usefulness of other inputs in rice cultivation. Construction of drainage systems is very essential for improving water management in paddy fields. The effect of different drainage systems including ...
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Proper water management in paddy fields is the most important operations that plays a fundamental role in the usefulness of other inputs in rice cultivation. Construction of drainage systems is very essential for improving water management in paddy fields. The effect of different drainage systems including three conventional subsurface drainage systems, a bi-level subsurface drainage system, and surface drainage system on the yield of Tarom rice cultivar were compared at the improved and consolidated paddy fields of Sari Agricultural Sciences and Natural Resources University. The experiment was conducted in a randomized complete block design with 5 treatments. At the harvesting time, some crop indices such as plant height, flag leaf length, main panicle length, tillering number, number of lateral branches of the main panicle, straw yield, biological yield, grain yield, and harvest index were determined. Statistical analysisrevealed that many of the determined indices in subsurface drainage treatments were significantly different than those of the control treatment. The grain yield of subsurface drainage treatments was 0.91-1.65 t/ha greater than that of surface drainage treatment. The maximum tillering number, plant height, grain yield, and straw yield belonged to the bi-level drainage plots, while surface drainage treatment had the lowest values for these parameters.