نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم کشاورزی، دانشگاه فنی و حرفهای، تهران، ایران.
2 گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی و منابع طبیعی، دانشگاه لرستان، خرم‌آباد، ایران.
3 گروه کشاورزی اکولوژیک، پژوهشکده علوم محیطی، دانشگاه شهید بهشتی، تهران، ایران.
4 گروه تولیدات گیاهی، دانشکده کشاورزی، مجتمع آموزش عالی سراوان، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Introduction: Global climate change has caused extensive changes in climatic parameters such as rainfall and temperature, ultimately affecting field crop productions. Accordingly, adaptation strategies such as identifying optimal planting date and supplementary irrigation can lead to sustainable production in rainfed cropping systems. Considering continuous climate change and its effects on the agricultural sector, especially in arid and semi-arid regions, it seems inevitable to provide adaptation strategies to reduce climate change's negative effects and increasing agricultural production. Accordingly, the present study aimed to investigate the effect of planting date and supplementary irrigation (SI) at important growth stages on wheat yield and growth in rainfed agro-ecosystems under baseline and future climate change conditions using the APSIM-Wheat model.
Materials and Methods: The current study focused on five locations (Bijar, Marivan, Saqqez, Qorveh, and Sanandaj) in Kurdistan province, Iran. The study locations were chosen based on being a cultivated rainfed wheat area, their climatic diversity, and the availability of long-term climate data (rainfall, sunshine duration, and minimum and maximum temperatures). The WeatherMan (Weather Data Manager) program embedded in Decision Support System for Agro-technology Transfer (DSSAT) package was used to restore and modify missing and outliers data in the study locations. The APSIM-Wheat model was applied to predict the wheat development and growth (Azar-2 cultivar). The performance of the crop model was evaluated based on the comparison of field-measured and simulated values for study traits. To do this, the Willmott index of agreement (d-index), normalized root mean squared error (nRMSE), mean bias error (MBE), determination coefficient (R2), and 1:1 line indicators were considered. The five GCMs under RCP8.5 scenario were singled out based on five possible climate characteristics, including cool wet (IPSL-CM5B-LR), hot wet (HadGEM2-AO), cool dry (GFDL-ESM2G), hot dry (MIROC-ESM), and middle (CESM1-BGC). Simulation experimental treatments in five locations were three irrigation regimes of (i) rainfed, (ii) SI at flowering stage, (iii) and SI at grain filling stage, and three planting dates of 1, 15, and 30 October at baseline period (1980-2010) and five GCMs under the RCP8.5 scenario for 2040-2070 period.
Results and Discussion: Large variability was detected in rainfed wheat grain yield depending upon planting date and irrigation regime in five studied locations. wheat plants differently responded to planting dates and irrigation regimes in the Kurdistan province, Iran and varied from 1.81 t ha-1 (rainfed × 30-Oct in Qorveh) to 5.76 t ha-1 (SI at flowering stage × 15-Oct and SI at grain filling stage × 15-Oct in Qorveh). The average grain yield of the entire wheat agro-ecosystems was 4.63 t ha-1. An increase of 6.9% was simulated for wheat grain yield entire Kurdistan province, Iran (as a semi-arid and cold agro-climatic zone) under future climate change conditions compared with the baseline. At the baseline period, the maximum wheat grain yield produced at an early planting date (1-Oct) in all locations except for Sanandaj, in which a mid-planting date (15-Oct) had the highest simulated grain yield. The simulated grain yields were maximized at a mid-planting date in studied locations except for Sanandaj, in which a late planting date (30-Oct) had the highest grain yield under future climate change conditions. The SI at flowering and grain filling stages had a similar effect on the wheat grain yield. Averaged by planting dates and locations, the wheat grain yield was increased by 8.7% when SI regimes were used compared with the rainfed treatment under climate change conditions.
Conclusion: The current findings showed that a mid planting date × SI at flowering/grain filling stages was identified as the best management practice under future climate conditions and can be suggested in semi-arid and cold agro-climatic zone for the autumn wheat in the Kurdistan province, Iran.
کلیدواژه‌ها [English]
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