استفاده از مدل SWAP به منظور شبيه سازي عملكرد محصول تحت مديريتهاي مختلف آبياري با آب شور در منطقه رودشت اصفهان

چكيده انگليسي :

AbstractThe salinity of soil and water resources is a major factor reducing agricultural production andgradually decreasing the agricultural land uses One effective method to reduce soil salinity is to useleaching and applying appropriate irrigation management To determine the effects of irrigationwater salinity and leaching on wheat yield and salt distribution pattern in soil a field experimentwas conducted at Rudasht east of Isfahan on a silty clay soil a typical soil of central part of Iran with three irrigation water salinity of 2 8 and 12 dS m without leaching and with leaching levels of4 19 and 32 with two irrigation water management method irrigation with uniform water qualityand irrigation by non saline water EC 2 dS m until germination then using saline water usingfactorial design with four replications for each treatment The results showed as the irrigation watersalinity increases the grain yield straw yield 1000 grain weight crop height spike length and leafarea index decreases significantly Grain yield was 5891 3717 and 2883 kg ha respectively Anincrease in grain protein was noted as the salinity of irrigation water increased Irrigationmanagement and leaching increase yield component and decrease grain protein but effect ofirrigation management on spike length leaf area index and grain protein and effect of leaching onstraw yield and grain protein was not significant Irrigation management was more effective thanleaching for increasing grain yield straw yield and seed protein In this region wheat was found tobe semi sensitive and semi tolerant crop in response to salinity The coefficients A and B of therelative yield equation were obtained as 5 3 dS m and 7 4 for the study area As the irrigation watersalinity increases the EC CO32 Cl SO42 Ca Mg and Na in soil decreases significantly Minimum and maximum of soil salinity was 4 2 and 9 4 dS m respectively Irrigation managementdecreases salinity and soil ions and leaching decreases the amount of Cl SO42 and Na in soil butonly effect of irrigation management in decreasing CO32 Cl and Na was significant Effect ofirrigation management on decreasing ions was more effective than leaching As the irrigation watersalinity increase soil moisture content increased and carbon and nitrogen decreased and leachingreduced soil salinity In treatments which were irrigated with 2 dS m water soil salinity increased indepth In treatments which were irrigated by 8 dS m water soil salinity increases to the depth of 30cm decreased to the depth of 60 cm and then remained constant In treatments which were irrigatedby 12 dS m water soil salinity increased to the depth of 30 cm and then decreased Effects ofirrigation water management and leaching on salt removal from soil was higher for the top soil layeras compared to the lower layers of soil Under leaching more salts were accumulated at the lowerdepths of soil The SWAP model was found have low sensitive to input data of root distributiondepth and irrigation water salinity Lane coefficient 8 and medium sensitive to climate date soilsurface layer hydraulic characters leaf area index and irrigation water amount sensitivitycoefficient of 27 This model was calibrated for the study area the coefficient determined squareroot mean error absolute mean and mean error were 0 68 0 71 0 39 and 0 19 respectively Thisresult shows that SWAP is usable in arid regions Calibrated model simulated yield and soil salinitywith R2 0 68 and 0 39 respectively The simulation of model under low soil salinity was better thanhigh soil salinity

منصوري، حامد

استفاده از مدل SWAP به منظور شبيه سازي عملكرد محصول تحت مديريتهاي مختلف آبياري با آب شور در منطقه رودشت اصفهان

خواص آب , شوري خاك