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Volume 17, Issue 46 (9-2017)
Abstract
Since the most important climatic parameter affecting sugar beet cultivation is the temperature, we carried out this research considering climatic elements such as temperature, precipitation and freezing days in relation to autumn sugar beet planting. Daily temperatures of selected stations in a period of 10 years (2005-2015) has been used for agroclimatic analysis. In order to evaluate that, thermal potential assessment, deviation from optimal conditions and active day gradient index (GDD) were used. The evaluation of thermal potential based on the threshold of 0, 4, and 10 degrees Centigrade at the station levels in Kermanshah province showed that Sar-e-Pol-e-Zahab Station has the highest cumulative thermal unit and Kangavar Station has the least one. In Isfahan province, Khour-va-Biabanak station has the highest cumulative thermal unit and Khansar station has the lowest unit. Based on the deviation from optimal conditions in Kermanshah province, Sar-e-Pol-e-Zahab station has the lowest (-27.79) and in Khour-va-Biabanak station (-21.78) had the least deviation from optimal conditions. Planting date at the stations was considered based on the autumn temperature. In Kermanshah province, Sar-e-Pol-e Zahab station had the earliest date of harvest (May 1st.), while this date in Isfahan province was for Khour-va-Biabanak station (May 9th.). Suitable areas for planting in Kermanshah province are found to be the eastern and northeastern regions of Sar-e-Pol-e Zahab and Qasr-Shirin. In the province of Isfahan, the northern and western parts of Khour-va-Biabanak and Kashan were the most proper regions and central areas are in the next steps.
Mrs Somayeh Naderi, Prof. Bohloul Alijani, Prof. Zahra Hedjazizadeh, Dr. Hasan Heidari, Dr. Karim Abbaspour,
Volume 24, Issue 73 (6-2024)
Abstract
Evidence suggests that climate change will create uncertain regional agricultural production stability in the coming decades. This research investigated the impact of climate change on hydrology and sugar beet yield as one of the main crops in the Urmia lake basin using the Soil and Water Assessment Tool (SWAT). To address this, a baseline SWAT model was setup for 1986-2014. Afterward, the output was calibrated (1989-2004) and validated (2005-2014) in the SWAT-CUP software using the SUFI2 algorithm to simulate streamflow of 23 gauging stations and crop yield. The Nash-Sutcliffe efficiency was 0.43 and 0.53 for calibration and validation periods, sequentially. The Percent Bias was 45% and 16% for calibration and validation periods, respectively. As well as the agreement indices of 0.71 and the little Percent Bias (-6% to 10%) for crop production, verified the model's efficiency. The next step was downscaling and bias-correction of the precipitation and temperature data received from 3 climate models, namely GFDL, HadGEM2, and IPSL under RCP4.5 and RCP8.5 using CCT program. Then, the downscaled data were fed to SWAT, and Finally, hydrological fluxes and sugar beet yield were estimated for 2021-2050. Despite a dispersion of precipitation changes ranging from -12% to +35% in most scenarios, results highlight the pivotal role that the warmer temperature (+2.7°C) increases evaporation, resulting in sharpened pressure on water resources and runoff, especially, at the beginning of crop growth season. Finally, the negative impacts on crop productivity (-45%) is not unexpected. This means that sugar beet may suffer from climate change impacts, and the production of this plant will change over the next period in this region.
Keywords: Climate Change, Sugar Beet, Urmia Lake Basin, Sensitivity Analysis, SWAT.
Mohsen Azizi, Hossein Mohammadi, Dariush Taleghani,
Volume 25, Issue 78 (9-2025)
Abstract
The aim of this research is to identify potential areas for autumn sugar beet cultivation in Golestan Province, Iran, based on temperature and precipitation parameters. Temperature (daily) and precipitation (annual) data from a 15-year statistical period (2006–2020) were analyzed using methods such as thermal potential diagrams, deviation from optimal conditions, phenology, and zoning of irrigation requirements based on annual rainfall. The results of the temperature evaluation using the thermal potential method, based on thermal thresholds of 0°C, 4°C, and 10°C, revealed that Inche Brun station has the highest cumulative thermal units, while Aliabad Katul station has the lowest. Analysis of the probability of late spring frost at the 95% confidence level showed that frost events occurring at the end of April in the central, eastern, northern, northeastern, and western parts of Golestan Province coincide with the phenological stages of root bulking and sugar accumulation in sugar beet. Based on the deviation from optimal conditions, Inche Brun station exhibited the lowest deviation (-20.64), indicating more favorable conditions for sugar beet cultivation. Phenological analysis identified Gonbadkavus, Bandar Turkman, Kalaleh, Inche Brun, and Bandar Gaz as the most suitable areas for autumn sugar beet cultivation in Golestan Province. Rainfall evaluations using the annual rainfall zoning map of Golestan Province indicated that, while there are no significant limitations in terms of rainfall and water supply for autumn sugar beet cultivation, the recent multi-year droughts necessitate additional irrigation to ensure optimal growth. In conclusion, this study highlights the potential for autumn sugar beet cultivation in specific areas of Golestan Province, taking into account thermal conditions, frost risks, and rainfall patterns. However, supplementary irrigation is recommended to address water shortages caused by prolonged droughts.
