• Growth, productivity and climate change assessments of drought tolerant rice cultivars under different crop management practices: simulations using CSM-CERES-Rice model in central terai of Nepal

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  • 29/02/2016

This MSc thesis study was conducted by Bishal Dhakal, student at the Tribhuvan University, as part of the SAF-BIN project in Nepal in 2014.

Rice is a staple food in Nepal, but its production is restricted due to rising erratic rainfall patterns, and fluctuating temperatures caused by climate change. Appropriate crop management practice and drought tolerant cultivars are climate smart methods to mitigate the effects. The evaluation and adaptation of these practices can be improved through crop simulation models. The aim of the study was to evaluate the model CSM-CERES1 Rice ver. 4.5 for its ability to simulate agronomic and climate change parameters of drought tolerant rice cultivars under different crop management practices. The study was carried out in Dhauwadi VDC2 Nawalparasi district, Nepal from June to October 2014. The field experiment was conducted in strip-plot designs at three farmers´ fields with 12 treatments based on three crop management practices3 and four varieties4. Biometric, yield attributing and economic data were recorded and statistically analyzed via ANOVA and Duncan's Multiple Range Test.  For the simulations study, the CSM-CERES-Rice model was calibrated5, validated and the sensitivity of the model to various agronomic and climatic parameters was performed.The field study revealed that grain yield, was significantly influenced by the management practices, but not by genetics. SRI3 achieved highest grain yields (5.28 t/ha) compared to the conventional and ICM3 practice (4.49; 4.73 t/ha). Moreover, SRI showed highest values for effective tillers/m2, panicle length and weight. There was no significant interaction effect of management practices and cultivars in grain yield, but in straw yield (highest: Sukkha-5 cultivar with SRI, 5.66 t/ha), and harvest index (highest: Sukkha-5 with conventional practice, 54.75%). SRI showed highest gross return, net return and B:C ratio. The simulation model was found well validated with days to anthesis, days to physiological maturity and grain yield and it was found sensitive to weather years, transplanting date, temperature, C02 concentration and solar radiation. Cultivar Sukkha-5 grown under SRI management practice showed best yield results. The CSM-CERES Rice Model was successful and showed the immense scope of using this model as a tool for estimating potential yields and effects of different agronomic and climate change parameters in the study area.


1 Cropping System Model (CSM)-CERES (Crop-Environment Resource Synthesis)
2 Village development committee

3 System of rice intensification (SRI), integrated crop management (ICM) and conventional management

4 Introduced varieties: Sukkha-3, Sukkha-4, Sukkha-5 and the local variety: Hardinath-2.

5 adjustment to genetic coefficients related to plant development and grain yield