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ali mokhtaran; abdolali gilani; sami Jalali; Leila Behbahani; mojtaba Rezaei; Kobra Tajaddodi Talab
Abstract
Rice is one of the most important summer crops in Khuzestan Province. Due to the severe water limitation, the effect of using strip drip system in the method of direct seeded rice in dry bed was monitored on the yield of common rice cultivars of the province and changes in soil salinity. This research ...
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Rice is one of the most important summer crops in Khuzestan Province. Due to the severe water limitation, the effect of using strip drip system in the method of direct seeded rice in dry bed was monitored on the yield of common rice cultivars of the province and changes in soil salinity. This research was conducted during 2019-20 and 2020-21, at the Ahvaz Agricultural Research Station on three adjacent plots of land, using split-plot design and randomized complete blocks in three replications. The main factor was irrigation including three levels: daily irrigation, every two days, and three days; and the secondary factor included three cultivars (Red Anbori, Champa, and Daniyal) and one salt tolerant rice line (S2). In the first year, due to the allocation of water outside the cultivation date, the yield of the crop was very low, so, the analysis was done based on the second year. The average volume of irrigation water in the field was measured as 14,800, 15,200, 15,700 and 16,100 m3/ha for, respectively, line S2, Red Anburi, Daniyal, and Champa. The results showed that, in the daily irrigation, the "Red Anburi" local cultivar had the highest yield with 3767 kg/ha and S2 line had the lowest 2541 kg/ha, so that when the irrigation changed from every day to three days, the yield decreased by 56% on average. The highest water productivity was obtained by the "Red Anburi" cultivar (0.25 kg/m3) in the daily irrigation. The reason for this problem can be shown in the monitoring of soil salinity, so that with daily irrigation, the salinity of the saturated extract in all soil layers showed a decreasing trend from 3.77 to 1.8 dS/m. According to the results, use of drip irrigation system would significantly reduce the volume of irrigation water compared to "conventional puddled transplanted rice". This has been an effective strategy in reducing the stress on the water resources of the province and saving the available water to preserve the ecosystem, although significant reduction of rice cultivation area in this province is recommended.
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ali mokhtaran; Peyman Varjavand; Hossein Dehghanisanij; Shokrola Absalan; Azarakhsh Azizi; Alireza Jafarnejadi
Abstract
This study was conducted to compare and monitor drip and surface irrigation systems for corn and wheat crops in three planting seasons from summer 2016 to spring 2018 in one of the agricultural research stations in Khuzestan, located in Ahvaz. The source of irrigation water was Karun River with salinity ...
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This study was conducted to compare and monitor drip and surface irrigation systems for corn and wheat crops in three planting seasons from summer 2016 to spring 2018 in one of the agricultural research stations in Khuzestan, located in Ahvaz. The source of irrigation water was Karun River with salinity of 3 dS/m in Ahvaz section. This study was performed using randomized complete blocks design with three replications. The basis of blocking in corn cultivation was 2 and 4 days irrigation intervals, and in wheat cultivation, the distances between drip lines were 40, 60, and 75 cm. The results showed that the volume of water used in the drip system for corn and wheat was 24% and 32% lower than the surface irrigation system, respectively. Also, water productivity in the drip system was higher than surface irrigation system by 16% and 21%, for corn forage and grain, respectively, and by 35% for wheat. Wheat water productivity for different distances of drip lines was not significantly different. Therefore, in heavy-textured soils, drip irrigation lines at 75 cm spacing can be used for wheat cultivation. In soil monitoring analysis, the drip system reduced soil quality such that, after three planting seasons, the initial non-saline-sodic soil (ECe = 3.09dS / m, ESP = 6.18%) became saline (ECe = 7.63dS / m, ESP = 12.63%). Despite accumulation of salts at the periphery of the wetted soil under the drippers, the plants had a better growth and yield in the drip system than the surface irrigation, because of the high soil water potential around the roots and under the drippers, which reduced salt effects. The results of this study showed that if a drip system is used for the climate similar to the central and southern regions of Khuzestan, land drainage and leaching operations at the end of the growing season are necessary to protect the soil.
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ali mokhtaran; abdali naseri; Heidarali kashkuli
Abstract
In the new drainage conditions in the center and southwest of Khuzestan Province, by reducing the depth of drainage installation and controlled drainage, studying the dynamics of the mixing zone, understanding the specifications of this region, and its effect on the flow rate of drainage water and salinity ...
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In the new drainage conditions in the center and southwest of Khuzestan Province, by reducing the depth of drainage installation and controlled drainage, studying the dynamics of the mixing zone, understanding the specifications of this region, and its effect on the flow rate of drainage water and salinity is important. In this study, seven groups of piezometers, each consisting of 8 piezometers placed at different soil depths (0.8 to 5m) and at different distances from the drainage water collector were studied in two research farms, namely, field R9-11 Dabal Khazaei agro-industry (with an average drainage depth of 2 m and distances of 65 m) and field R8-7 in Salman Farsi agro-industry (with an average depth of 1.4 meters and 42 meters distances).Water level in piezometers, water salinity in different soil layers, and drainage water flow rate and salinity were monitored daily in three periods of heavy irrigation of sugarcane (March to October of 2013, 2014 and 2017). Results indicated that by starting a heavy irrigation, hydraulic head increased and hydraulic head variance between bottom layer (4 and 5 m) relative to the surface layers, established vertical flow and saline inflow upwards. Reducing the installation depth of drains up to 60 cm from in R9-11 compared to farm R8-7 and moving away from the collector up to 400 m in each farm, reduced the installation depth of drains up to 40 cm, and increased the hydraulic load by an average of 8-12 cm. The thickness of the mixing area was up to one meter and the reduction of the average salinity line in the mixing area was 8%. It was found that in addition to irrigation water salinity, drainage water salinity was affected by groundwater salinity and the difference in drainage depth, position of the impermeable layer, and the presence of sand lenses. By decreasing drainage depth, the drainage water discharge decreased sharply, such that the averag drainage water from each lateral in farm R9-11 was 10 mm/day, and in farm R8-7 it was 3.3 mm/day. The results showed that with increasing the thickness of the salt and fresh water mixing zone due to the optimal reduction of drainage depth, the volume of water consumed in each irrigation cycle decreased due to plant use of this zone, which can be an effective factor in conserving soil and water resources.
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ali mokhtaran; mehrzad tavoosi; Peyman Varjavand; Saloome Sepehri Sadeghian
Volume 34, Issue 3 , September 2020, , Pages 337-354
Abstract
< p > < p >In Khuzestan Province, drainage water production from various activities, especially agriculture, is a serious problem. In order to optimize the use of drainage water, cultivation of salinity resistant crops can be considered as a suitable practice. Therefore, in 2019, a ...
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< p > < p >In Khuzestan Province, drainage water production from various activities, especially agriculture, is a serious problem. In order to optimize the use of drainage water, cultivation of salinity resistant crops can be considered as a suitable practice. Therefore, in 2019, a study was conducted to investigate the possibility of recycling drainage water of sugarcane fields for winter cultivation of quinoa in the Research Farm of Mirza Kuchak Khan Sugarcane Agro-Industry Company in southern Khuzestan. This study was performed as split plots with a complete randomized block design with two factors and three replications. The main factor was the management of irrigation water including the use of Karun river water, drainage water of sugarcane fields, and intermittent-periodic irrigation (alternating application of Karun water and drainage water). The sub-plots were allocated to four genotypes of quinoa including "Giza1, Titicaca, Rosada, and Q26". Interaction of irrigation water type with genotype showed that the highest biomass in terms of dry forage (3645.6 kg/ha) belonged to Giza1 genotype using irrigation with Karun water, which statistically had no difference with the Rozada biomass (2620 kg /ha) using irrigation with drainage water. Monitoring of soil "ECe" and "ESP" during the growing season showed that for the two treatments of irrigation with the water of the Karun River and intermittent-periodic irrigation, the farm soil up to 1 meter depth was non saline and non-sodic. This is while before cultivation of quinova, the soil layer of 0- 25 cm was saline (5.54 dS/m) and the deeper parts were non-saline. In irrigation with drainage water, the 0-25 cm layer soil remained saline due to the effect of evaporation. However, in layers deeper than75 cm, due to the accumulation of salts compared to pre-planting (ECe=2 dS/m), salinity reached ECe=4dS/m and ESP=7%. These results indicate the need for leaching at the end of the growing season and the importance of drainage for salt outflow from agricultural lands to maintain soil salt balance in areas where drainage water recycling is practiced.