نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد، گروه مهندسی آب، دانشکده علوم کشاورزی، دانشگاه گیلان، رشت، ایران
2 دانشیار، گروه مهندسی آب، دانشکده علوم کشاورزی، دانشگاه گیلان و گروه پژوهشی مهندسی آب و محیط زیست پژوهشکده حوزه آبی دریای خزر، رشت، ایران
3 استادیار پژوهش، مؤسسه تحقیقات برنج کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، رشت، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction
Increasing irrigation water productivity is one of the key topics in food production in different countries of the world, especially in water-scarce countries such as Iran. Plant growth models, in addition to predicting yield, are capable of evaluating diversity and risks of different management scenarios. Plants modeling can lead to a reduction in the use of production resources by finding optimal management scenarios. The objective of this study was to simulate the physical water productivity, leaf area index and evapotranspiration of three rice genotypes under different irrigation and nitrogen fertilizer managements using the CERES-Rice model.
Materials and methods
This experiment was conducted with 36 treatments in a split-plot design based on randomized complete block design with three replications in the Rice Research Institute of Iran, Rasht, Guilan province, Iran, during two cropping years, 2017 and 2018. Irrigation management at four levels including permanent flood irrigation and intermittent irrigation with irrigation intervals of 7, 14, and 21 days was considered as the main factor, rice genotypes at three levels including the certified local variety Hashemi, line M5 and M12 line as the sub-factor, and nitrogen fertilizer at three levels including 60, 80 and, 100 kg/ha net nitrogen fertilizer as the sub-sub-factor. After harvest, grain yield was measured in kg/ha and then irrigation water productivity was calculated from the ratio of grain yield to water volume used. In this study, the plant growth model of CERES-Rice version 4.7.5 was used for modeling, and data from 2017 and 2018 were used to validate and calibrate the model, respectively. Graphical comparative methods and statistical indicators including root mean square error (RMSE), normalized root mean square error (NRMSE) and model efficiency (EF) were also used to evaluate the model performance.
Research findings
The results of this study showed that the predicted yields of the CERES-Rice model had a similar trend to the actual yields and the response to irrigation treatments was the same as the measured yields. The results of the simulation of water productivity under different irrigation and nitrogen fertilizer managements for data from 2005 to 2016 with the aim of evaluating water productivity in a long-term meteorological period revealed that the irrigation intervals of seven days at 100 kg/ha nitrogen fertilizer level was the best irrigation management for the studied years. The irrigation intervals of 14 and 21 days at the level of 100 kg/ha nitrogen fertilizer also had more appropriate physical water productivity.
Conclusion
The results of water productivity modeling showed that a seven days irrigation interval at 100 kg/ha nitrogen fertilizer was the best irrigation interval. Therefore, the development of seven days intermittent irrigation and education and promotion of proper utilization by farmers are recommended to increase water productivity. Therefore, in order to increase water productivity, it is recommended to develop seven days intermittent irrigation and educate and promote proper utilization by farmers.
کلیدواژه‌ها [English]
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