mohammad reza nouri emamzadei

Surface border irrigation design and variables determination using multi-objective optimizationM. Saleki , M.R. Nouri , H.R. Salemi , R. Fatahi AbstractDesign of surface border irrigation systems is usually performed based on empirical relations presented in the literature or through simulation results in various models. These methods do not allow investigating the impact of all design variables on different irrigation indices.Designing based on minimizing the volume of water input along with maximizing indices such as application efficiency, distribution uniformity, and irrigation adequacy is a new approach that can provide the best results through multi-objective optimization. The best choice for design variables, including length, width, slope, inflow rate, and cut-off time in a field, can be obtained using this method to achieve optimal indices.In this research, by measuring the water advance in sample plots in a field in Isfahan and simulating water movement in the border strips, the soil infiltration coefficients were obtained. Based on this, for a net irrigation depth of 75 mm and a roughness coefficient of 0.15, 56700 closed-end border irrigation events were simulated using WinSRFR 5.1 software. Among the obtained results, using the constrained objective function multi-objective optimization method, with the aim of minimizing the volume of water input and application efficiency higher than 90%, distribution uniformity and irrigation adequacy more than 0.8, 515 optimal options for designing the irrigation border strips were determined, and among them, some options were presented for the optimal design of the irrigation border strips in this field and similar fields.The results show that the volume of water input in the optimized options is between 712.8 and 757.3 cubic meters per hectare, which is significantly different from the measured values in the field. The method presented in this research can be used as a new approach for designing surface border irrigation systems and increasing water productivity in agriculture.

Drought stress is one of the limiting factors of agriculture in many parts of the world, especially Iran. Understanding the mechanism behind drought stress’ effect on physiological and biochemical processes of genotypes is very useful for selecting and breeding genotypes compatible with Iranian conditions. For this purpose, the present study has been conducted in 2018-2019 in the Biotechnology Research Institute of Shiraz University to investigate the effect of drought stress on physiological and biochemical characteristics of both years’ old pomegranate seedlings of Wonderful cultivar in greenhouse conditions. Irrigation has been carried out at four levels of 100% (control), 75%, 55%, and 35% of field capacity for 50 days. The experiment is based on a completely randomized design with three replications. The results show that drought stress has significantly increased carotenoids, flavonoids, malondialdehyde, and proline. The relative leaf water content, cell membrane stability and anthocyanins has decreased, though there has been no significant difference in chlorophyll and glycine betaine levels between drought treatments. Also, the hydrogen peroxide (81%) and activity of superoxide dismutase (480%), catalase (96%), and ascorbate peroxidase (96%) in 35% of field capacity significantly has increased. According to the results of this study, especially the increase in proline and antioxidant enzymes under drought stress, tolerance mechanisms in pomegranate cultivar Wonderful can be associated with active osmotic regulation and active enzymatic antioxidant system.

Water is the source of life and one of the important resources for the sustainable development of countries. Population growth and consequently the need for more agricultural commodities and food products and on the other hand, the limitation of water resources, have led human beings to the optimal use of available water resources and the use of low-quality water (Dehghan et al. 2015). To make more efficient use of limited water resources in the agricultural sector, new strategies such as the use of unconventional and saline water in irrigation operations should be considered (Mardani Nejad et al. 2017). Knowing how plants respond to different degrees of salinity of irrigation water, which is used in different stages of vegetative and reproductive growth, is necessary for proper and optimal management of the use of unconventional water resources in agriculture. Beans are one of the most important crops in terms of high protein content and use in the diet. This plant is one of the annual legumes and is sensitive to water salinity, which is cultivated for seed production (Salehi, 2015b). Bean is one of the plants sensitive to salinity and tolerates salinity up to 2 dS/m, but its yield reduction starts from 0.8 dS/m (Kamel et al. 2016).This experiment was carried out to compare the effects of saline water application in vegetative and reproductive growth stage for irrigation of Derakhshan red bean cultivar, which is suitable for Shahrekord climatic conditions. Experiments of this pot study in open space, were performed in factorial form in a completely randomized design, with three replications in pots with a diameter of 40 and a height of 70 cm in the research farm of Shahrekord University with UTM coordinates (Zone = 39), X = 482573 m and Y = 3579364 m and altitude of 2070 m above sea level. The first factor of the experiment was the use of saline water at the mentioned three levels for irrigation in the vegetative growth stage and the second factor was the use of the same salinity levels for irrigation of reproductive growth stage. The data collected included yield, yield components and water productivity.The results of analysis of variance showed that salinity stress in the vegetative and reproductive growth stage of bean plant significantly reduces yield, yield components, water uptake, water productivity and biological productivity index (α <0.01). Harvest index was not affected by salinity stress at vegetative growth stage, while the effect of salinity stress at reproductive growth stage on harvest index was significant (α <0.01). The highest value of water productivity was achieved in the control treatment with a rate of 0.67 kg/m3; the lowest value of 0.39 kg/m3 was observed in the treatment of applying 2 dS/m saline water in two stages of vegetative and reproductive growth. Regardless of salinity level, the mean effects of salinity in vegetative growth stage led to the productivity of 0.64 kg/m3 and in reproductive growth stage led to the productivity of 0.59 kg/m3. The results also showed that the highest yield (3349 kg/ha) was related to the control treatment and the lowest yield with rate of 1779 kg/ha was related to the treatment of applying 2 dS/m saline water in two stages of vegetative and reproductive growth. Regardless of the salinity level, the mean effects of salinity led to the production of 3067 and 2892 kg / ha grain yield in the vegetative and reproductive growth stage, respectively. The highest amount of water uptake was observed in the control treatment with the rate of 10 mm/day and the lowest amount of 9 mm/day without significant difference in the treatment with a salinity of 2 dS/m in the whole growth period and the treatment of 2 dS/m in the vegetative growth period And 1.5 dS/m was observed during reproductive growth.The results of this experiment, like the results of Ben Usher et al., 2006, showed that increasing salinity during the vegetative growth period of the plant reduces the storage content of plant organs, which affects the yield and its components at the end of the period. On the other hand, the application of salinity stress during reproductive growth period has a direct negative effect on yield and its indicators. These effects will be exacerbated when salinity stress is applied simultaneously during the vegetative and reproductive growth stages. The effects of salinity stress on grain yield and water productivity were more significant in the reproductive growth stage. The result is that in conditions of limited water quality, in order to achieve higher yield and optimal use of water, water with suitable quality should be used in the reproductive growth stage, and saline water could be used in the vegetative growth stage.

Clogging of emitters is one of the main problems in subsurface drip irrigation. The objective of this study was investigation of effect of Geocomposite on wetting pattern in subsurface irrigation system. This research was conducted in lysimeters located at Shahrekord University research field. The study was conducted as a factorial experiment based on a completely randomized design with 10 treatments and three replications of three factors. The first factor of experiment was geocomposite shape with the same area on two levels (shape square with dimensions (4 × 4) square centimeters and rectangular with dimensions (2 × 8) square centimeters), the second factor was combination of geocomposite material on two levels (two layers of geotextile on both sides of Geonet and The second level, a layer of geomembrane and a layer of geotextile on both sides of geonet), the third factor of placement in the soil at on two position (horizontal and vertical) and emitter with envelopment (in two position horizontal and vertical) were used as control. The ground wet and wet the maximum of soil depth profiles were measured. The results was showed that geocomposite of shape square with dimensions (4 × 4) square centimeters for a layer of geomembrane and a layer of geotextile on both sides and how to align horizontally in the soil wet ground level by lowering the 21.55 percent and increased 17.1 percent wet the soil deep profile compared to control (emitter with envelopment horizontally in the soil) is the most effective and best conditions on wetting profiles.

Application of mulches not only affects the physical and chemical properties of soil, but improves infiltration maintenance. In this study, evaluated during four month, the effects of wheat straw, maize straw, sawdust, leaves and superab A200 on the soil physical properties including soil bulk density, capacity water in the soil and cumulative infiltration. The effects of mulch compared in both cases tillage and no tillage, under modle complete block randomized design experiment with split plot in time. Results showed Mulch reduces bulk density but over time, bulk density in all mulchs except of superab A200, were increasing. Use mulch experiments increased water-holding capacity of the soil. In case tillage treatments, wheat straw and in case no tillage treatments superab A200 increasing water-holding capacity. After time increase cumulative infiltration in the wheat straw, maize straw and superab A200 significantly, compared to sawdust and leave mulches.

In arid and semi-arid regions due to restriction of access to fresh water resources for agricultural production, the major source of irrigation water is salt water. It was argued that the use of magnetic technology and salt water pass through a magnetic field can be helped to improve crop yield where salt water is used. In this regard to investigate effect of salt water passes through the magnetic field on the growth characteristics and yield components of green pepper, an experiment was conducted as completely randomized with split plot design by six treatments and three replications at University of Shahrekord in the summer of 2013. Treatments included two water levels (magnetic and non-magnetic) and salinity at three levels (0.3, 2.3 and 4.2 dS/m). The results showed that magnetic water increases of 12, 19 and 33 percent of the total fruit yield in irrigation water with salinity respectively 0.3, 2.3 and 4.2 dS/m. Also all yield components of the including fresh and dry weight of leaves, stems, roots and root volume of treated water with salinity of 0.3 dS/m highest values than the two others. Magnetic water increases 15 and 11 percent in the weight of stems in salinity of 2.3 and 4.2 dS/m than other non-magnetic levels of its.

Non-uniform distribution which occurs during manual fertilizing is one of the biggest problems of surface irrigation. This issue needs more research in the field of surface fertigation. The aim of this study is to evaluate the roles of slope and fertigation timing in furrow irrigation. Urea fertilizer was used and nitrate was selected to be the reagent ingredient in order to study the distribution of fertilizer. The research was conducted in agricultural research field of Shahrekord University. A completely randomized block design was employed with four treatments and three replications. The treatments were Control treatment (natural slope, fulltime fertigation) and three periods of fertigation that were first half, second half and fulltime fertigation. Slope changes, fertigation duration, soil depth of the sampling and distance from the furrow beginnings effects were studied on nitrate distribution in the soil. The LSD test was used for statistical analysis. The results demonstrated that slope had a very significant effect on nitrate distribution and storage in the soil (P<0.01). Also, Changes in fertigation timing and duration caused variation in nitrate distribution and the second half fertigation treatment had the highest nitrate distribution uniformity and absorption of 1653.53 mg/kg. Studying simultaneous effects of fertigation timing, soil depth and distance form beginnings of the furrows exhibited that they had no significant impact on each other. Finally, slope and fertigation timing were reported to be the effective factors in the nitrate storage and distribution.

The shortage of irrigation water with suitable quality for use in domestic, irrigation and industrial sectors is one of the most important problems in arid and semi-arid regions that include one-third area of the world. There is a progressive request for low quality water in regions, due to fresh water shortage. Therefore, many efforts have been taken place to decrease water salinity and increase the quality of abnormal waters such as saline and brackish waters. In this research, the impact of wheat straw and sawdust in sand filters on the physical and chemical properties of water was investigated and compared. For this purpose, saline water passed through a column of pure sand, a column of mixed wheat straw and sand and a column of mixed sawdust and sand, all having the same weight. The turbidity, hardness, chloride anions, magnesium and calcium cations concentration were measured with time. The results showed that the highest sorption of chloride anions (30 percent), magnesium (22 percent) and the maximum reduction of turbidity (74 percent) and hardness (19.27 percent) were achieved by passing water through straw wheat, but the sawdust had the most impact on electrical conductivity reduction (6.34 percent) and removal of calcium cations (23.7 percent) from saline water.