AgMIP-Pakistan is conducting three extensive field experiments on rice, maize and wheat, sown in long series of sowing date, to collect the data for multi-model evaluation and improvement.

Crop models are based on the simplification of real crop growth system. Models can simulate but are uncertain in their results inherently. These models differ in their basic structure, formulation, parameters and approach. There are different methods to evaluate the models performance such as inter-comparison, sensitivity analysis, uncertainty analysis and comparison of observed and simulated output of models. These analytic tools will simulate cultivar differences in the response of phenology, growth and yield to sowing date (changing photoperiod and thermal). Sowing date among crop management practices has the very significant impact on crop growth and development. Many rice, maize and wheat models allow for quantitative differences among cultivars in vernalization requirement and photoperiod sensitivity.

Pakistan has variety of season and changing photoperiod. To check the sensitivity of models for photoperiod, variable sowing date is the only possible option. The collected data set will be used to multi-model evaluation in changing photoperiod and response of rice, maize and wheat in series of sowing date. Finally, these data will help for the improvement in the crop models simulation, multi-models inter-comparisons for the best model in Pakistan’s conditions and new model development for Pakistan.

Multi-Model Evaluation with Changing Photoperiod in Series of Wheat, Rice and Maize Sowing Dates: A Step for Model Improvement.