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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.
Fatemeh Meskini-Vishkaee; Alireza Jafarnejadi; Naser Davatgar
Abstract
Irrigation water scarcity is one of the major limiting factors in agricultural production. This study was conducted to investigate the effect of different intensities of water deficit stress on yield and water use efficiency of Chamran 2 wheat cultivar in a moderate-textured soil in Khuzestan province. ...
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Irrigation water scarcity is one of the major limiting factors in agricultural production. This study was conducted to investigate the effect of different intensities of water deficit stress on yield and water use efficiency of Chamran 2 wheat cultivar in a moderate-textured soil in Khuzestan province. In this research, 10 treatments including full irrigation and water deficit stress at three intensity levels (low, moderate, and severe) were applied under two conditions: during whole growing season or at a given stage of plant growth. This research was done as a completely randomized design with three replications. The salinity of studied soil was 2.95 dS m-1, and soil texture was silty clay loam. The mean water use in different stress treatments was less than full irrigation by 17% (moderate-intensity stress in the third growth stage of wheat) to 43% (high-intensity stress throughout the plant growth period). Applying different intensities of water stress caused reduction in wheat grain yield by 13% (low-intensity stress throughout the growth period) to 76% (high-intensity stress throughout the growth period). The results showed that water stress at stem elongation and grain filling stages of wheat reduced the grain yield more than stress at flowering and milk stages. The lowest value of mean thousand kernel weight (28 g) was observed in the treatments applied in the final growth stage of wheat, confirming the importance of irrigation effects during grain filling stage on the quality of grain. The overall water use efficiency in low-intensity water stress (0.78 g L-1) was higher than the full irrigation treatment (0.62 g L-1), probably due to the reduction of irrigation water losses by drainage and evaporation.
alireza jafarnazhadi; seyyed mohammad hadi mousavi fazl
Abstract
Nowadays, application of unconventional water such as wastewater is one of the strategies for preventing water deficit. This study was conducted to evaluate effect(s) of treated wastewater application on microbial and chemical contamination of soil and wheat (Chamran V.). Five treatments included T1 ...
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Nowadays, application of unconventional water such as wastewater is one of the strategies for preventing water deficit. This study was conducted to evaluate effect(s) of treated wastewater application on microbial and chemical contamination of soil and wheat (Chamran V.). Five treatments included T1 (irrigation with 100% fresh water), T2 (75% fresh water + 25% wastewater), T3 (50% fresh water + 50% wastewater), T4 (25% fresh water + 75% wastewater), and T5 (100% wastewater) that were conducted with three replications, in a randomized complete blocks design in the research station of Ahvaz Agricultural Research Center. The irrigations were done based on soil moisture monitoring. The volumes and the time of irrigation were determined based on the 70% soil Field Capacity. The soil (0-30 cm) and plant (seed) samples were taken during wheat growth periods and were analyzed for some parameters such as soil microbial population as well as cadmium (Cd) concentration and micronutrients in soil and plant. The results showed that the total soil Cd concentration in 95% of the samples was less than 1.6 mg.kg-1. However, soil DTPA-Cd concentrations in all the treatments decreased compared to initial Cd soil content. The results revealed that wastewater treatments had no significant (p<0.05) effect on seed microelements, except Fe. The average soil DTPA-Cd in each wheat growth stage did not increase compared to its initial concentration. The soil microbial population at different growth stages was not significantly different (p<0.05) in T3 and T5 treatments, possibly due to growth limitations as a result of nutrient accessibility limitation. It may be concluded that the application of wastewater (along with fresh water) had no adverse effect on soil and wheat quality in short term. However, long term application of unconventional waters may cause contamination in soil and agricultural products.