نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 دانشگاه آزاد اسلامی واحد گرگان
2 استاد گروه زراعت دانشگاه علوم کشاورزی و منابع طبیعی گرگان
3 دانشگاه شهید بهشتی
4 دانشیار / دانشگاه آزاد گرگان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: Climate change is considered the most important threat to sustainable development in the current era. In this context, the agricultural sector receives the greatest impact from climate change due to extensive and direct interactions with its environment. The increase in temperature and heat stress caused by climate change is one of the biggest risks and concerns for grain maize production. Accordingly, it is necessary to investigate solutions to deal with the declining maize grain yield.
Materials and methods: Therefore, in order to better understand the optimization of sowing date in mitigating the effects of temperature increase on grain maize (Zea mays L.) yield in six regions including Islamabad, Kangavar, Kermanshah, Ravansar, Sararoud and Sarpol Zahab in Kermanshah province, simulation and crop model were used. In this study, climate data for the years 1980-2009 (as the base period) were received from the Meteorological Organization, and meteorological data for the future period 2040 to 2069 were generated using the HadGEM2-ES general circulation model. Exponential downscaling of climate-generating climate parameters was performed with climate scenario generation tools in the form of the AgMIP project and in R software. The IPCC Fifth Assessment Report was used to simulate future climate conditions under two climate scenarios RCP4.5 and RCP8.5. After simulating the future climate and generating the required parameters (minimum temperature, maximum temperature, precipitation, and solar radiation), growth and development simulation was performed using the SSM-Maize crop model under current conditions and climate change conditions, and the role of changing the sowing date as an adaptation option in dealing with the adverse effects of temperature increase in six cities of Kermanshah province with different climatic conditions was evaluated.
Results: The results showed that the average grain yield in all locations (except Sarpul Zahab) declined up to -3.8% and -6.5% under RCP4.5 and RCP8.5, respectively, compared to the baseline. The decline is largely due to the shortening of the crop growth period and the increase in average air temperature throughout the growing season. Based on the findings of this research, maize crop under climate change conditions can experience more moderate temperature conditions and a longer growing season by changing sowing dates, which could have a significant effect in reducing the adverse effects of rising temperatures on crop yield. In fact, with climate change, early sowing (the earliest sowing date) in areas such as Islamabad, Kermanshah, Ravansar, and Sararoud, which are part of a cold climate, resulted in an increased grain yield by +2.61 and +4.54% under RCP4.5 and RCP8.5, respectively, while delaying the sowing date (May 19th) in Sarpol Zahab, which is part of the hot climate, could increased grain yield by +2.11 and +6.29% under RCP4.5 and RCP8.5, respectively, compared to common sowing dates.
Conclusion: Changing the sowing date can be a simple and effective solution to reduce the negative effects of rising temperatures due to climate change on maize grain yield in various climates of Kermanshah province. The findings of the current study showed that along with breeding activities, policy makers and extension agents of the agricultural sector can help farmers reduce the adverse effects of climate change on grain maize by compiling the cropping calendar and choosing the appropriate sowing date based on future climatic conditions.
کلیدواژه‌ها [English]
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