@article { author = {Farrokhi, E. and Nassiri Mahallati, M. and Koocheki, A. and beheshti, alireza}, title = {Simulation of Growth and Development of Tomato (Lycopersicon esculentum Mill.) under Drought Stress: 2- Simulation of Water Productivity, Above Ground Biomass and Yield}, journal = {Water and Soil}, volume = {35}, number = {5}, pages = {627-643}, year = {2021}, publisher = {Ferdowsi University of Mashhad}, issn = {2008-4757}, eissn = {2423-396X}, doi = {10.22067/jsw.2021.15035.0}, abstract = {Introduction: Predicting yield is increasingly important to optimize irrigation under limited available water to enhance sustainable production. Calibrated crop simulation models therefore increasingly are being used an alternative means for rapid assessment of water-limited crop yield over a wide range of environmental and management conditions. AquaCrop is a multi-crop model that simulates the water-limited yield of herbaceous crop types under different biophysical and management conditions. It requires a relatively small number of explicit and mostly-intuitive parameters to be defined compared to other crop models, and has been validated and applied successfully for multiple crop types across a wide range of environmental and agronomic setting. This study was conducted as a two-year field experiment with the aim of the simulation of water productivity, above ground biomass and fresh and dry yield of tomato using AquaCrop model under different irrigation regimes applied at two growth stages in Mashhad climate conditions.Materials and Methods: A two-year field experiment was conducted during 2016-2017 growing seasons in the experimental field of Ferdowsi University of Mashhad located in Khorasan Razavi province, North East of Iran. The water-driven AquaCrop model developed by FAO was calibrated and validated to simulate water productivity, above-ground biomass and yield of tomato crop under varying irrigation regimes. AquaCrop was calibrated and validated for tomato under full (100% of water requirements) and deficit (75 and 50% of water requirements) irrigation regimes at vegetative (100V, 75V, and 50V) and reproductive stages (100R, 75R, and 50R). Model performance was evaluated in terms of the normalized root mean squared error (NRSME), the Nash–Sutcliffe model efficiency coefficient (EF), Willmott’s index of agreement (d) and coefficient of determination (R2). The drip irrigation method was used for irrigation. The tomato water requirement was calculated using CROPWAT 8.0 software. The irrigation water was supplied based on total gross irrigation and obtained irrigation schedule of CROPWAT. The 2016 and 2017 measured data sets were used for calibration and validation of AquaCrop model, respectively.Results and Discussion: Calibration results showed good agreement between simulated and observed data for water productivity in all treatments with high R2 value (0.93), good ME (0.23), low estimation errors (RMSE=0.09 kgm3) and high d value (0.85). The goodness of fit results showed that measured WP values were closer to simulated WP values for the validation season (2017) than for the calibration season (2016). During calibration, (2016), the model simulated the biomass with good accuracy. The simulated above ground biomass values were close to the observed values during calibration (2016) for all treatments with R2 ranging from 0.92 to 0.99, NRMSE in range of 7.4 to 23%, d varying from 0.94 to 1, and ME ranging from 0.71 to 0.98. Validation results indicated good performance of model in simulating above ground biomass for most of the treatments (0.92 < R2 < 0.98, 6.5% < NRMSE < 21.3%, 0.76 < ME < 0.99). During validation (2017 growing season), overall, the trend of biomass growth (or accumulation) was captured well by model. However, the range of biomass of simulation errors was high, especially in treatments with higher stress. Accurate simulation of the response of yield to water is important for agricultural production, especially in an arid region where agriculture depends closely heavily on irrigation. During validation, the model predicted dry and fresh yield satisfactorily (NRMSE = 15.64% and 11.80% for dry and fresh yield, respectively).Conclusion: In general, the AquaCrop model was able to simulate the observed water productivity, above ground biomass and yield of tomato satisfactorily in both calibration and validation stage. However, the model performance was more accurate in non- and/or moderate stress conditions than in sever water-stress environments. In conclusion, the AquaCrop model could be calibrated to simulate growth and yield of tomato under temperate condition, reasonably well, and become a very useful tool to support decision on when and how much irrigate. This study provides the first estimate of the soil and plant parameter values of AquaCrop for simulation of tomato growth in Iran. Model parameterization is site specific, and thus the applicability of key calibrated parameters must be tested under different climate, soil, variety, irrigation methods, and field management.}, keywords = {Aquacrop model,Deficit irrigation,Modelling,Vegetative and reproductive stages,Water Productivity}, title_fa = {شبیه‌سازی رشد و نمو گوجه‌فرنگی (Lycopersicon esculentum Mill.) تحت شرایط تنش خشکی: 2- شبیه‌سازی بهره‌وری آب، زیست‌توده و عملکرد}, abstract_fa = {پیش‌بینی عملکرد محصول با هدف بهینه کردن میزان آب آبیاری به خصوص هنگامی که آب قابل دسترس محدود باشد، برای افزایش پایداری در تولید بسیار حائز اهمیت است. در این مطالعه مدل آب محورِ آکوواکراپ که توسط فائو توسعه داده شده است، به منظور شبیه­سازی بهره­وری آب، زیست توده و عملکرد گوجه­فرنگی تحت رژیم­های مختلف آبیاری واسنجی و صحت­سنجی شد. آزمایش در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد در دو سال زراعی 1396-1395 اجرا شد. واسنجی مدل با استفاده از داده­های سال 1395 و صحت­سنجی مدل با استفاده از داده­های سال 1396 انجام شد. در این مطالعه مدل آکوواکراپ تحت شرایط آبیاری کامل (100 درصد نیاز آبی) و کم آبیاری (75 و 50 درصد نیاز آبی) اجرا و در دو مرحله رویشی و زایشی برای محصول گوجه­فرنگی واسنجی و صحت­سنجی شد. کارایی مدل با استفاده از میانگین مربعات خطای نرمال­شده (NRMSE)، کارایی مدل (EF)، شاخص توافق ویلموت (d) و ضریب تعیین (R2) مورد ارزیابی قرار گرفت. مدل آکوواکراپ به منظور شبیه­سازی بهره‌وری آب، زیست­توده بالای سطح خاک و عملکرد خشک میوه گوجه­فرنگی برای همه تیمارهای آبیاری به‌ترتیب با مقادیر شاخص­های آماری 14/81%=NRMSE، 0/85=d، 0/93=R2، %23>NRMSE>4/%7، 1>d>0/94، 0/99>R2>0/92 و 97/%9=NRMSE، 96/0=d، 86/0=R2 واسنجی شد. در طول مرحله صحت­سنجی، 13/64%=NRMSE، 0/90=d، 0/23=R2، 3/%21>NRMSE>5/%6، 1>d>0/95، 0/98>R2>0/92 و 15/64%=NRMSE، 0/95=d، 0/95=R2 به‌ترتیب برای بهره­وری آب، زیست توده بالای سطح خاک و عملکرد خشک میوه گوجه­فرنگی بدست آمد. به طور کلی توانایی مدل آکوواکراپ در شبیه­سازی مقادیر بهره­وری آب، زیست­توده بالای سطح خاک و عملکرد مشاهده شده رضایت­بخش بود، با این وجود کارایی مدل با افزایش تنش آب کاهش پیدا کرد.}, keywords_fa = {آکوواکراپ,مرحله رویشی و زایشی,کم آبیاری,مدل‌سازی,بهره‌وری آب}, url = {https://jsw.um.ac.ir/article_40438.html}, eprint = {https://jsw.um.ac.ir/article_40438_f2e8b6cf60ec459387d73919ff03138c.pdf} }