Abstract:

【Objective】 The harvest index model of winter wheat in China based on meteorological data was established for supporting crop yield model. 【Method】 Based on observed data of winter wheat and meteorological data during recent twenty years from thirty agrometeorological stations in Henan, Hebei and Shandong provinces, the trend and meteorological harvest index were extracted by using time-series analysis method. The trend harvest index was separated from the measured harvest index by linear fitting; the meteorological harvest index was then calculated by subtracting the trend harvest index from the measured one, and the relationship between the meteorological harvest index and the meteorological factors was studied by stepwise regression analysis which simulated the influence of the changed meteorological factors on winter harvest index. 【Result】Correlation analysis suggested that the meteorological harvest index of winter wheat significantly correlated with the meteorological factors during the growth period. However, the influencing factors were different in different scales. Both statistical models of single station scale and regional scale were validated, respectively, using other data (n=209). The model validation showed that, the simulated linear regression as against measured harvest index yielded a correlation coefficient (r) of 0.65 with a slope of 0.42, the root mean squared error of 12.2%, the mean bias error of -2.4%, the index of agreement of 75.8% and the model efficiency of 42.3% on the single station scale, and the model almost explained the total variance. The simulated regression against measured harvest index yielded a correlation coefficient (r) of 0.56 with a slope of 0.33, the root mean squared error of 13.3%, the mean bias error of -1.3%, the index of agreement of 69.0% and the model efficiency of 31.7% on regional scale. 【Conclusion】 The established models can well simulate the change of winter wheat harvest index under different meteorological conditions. The winter wheat harvest index model coupled with crop net primary production model can be used to do research on simulating winter wheat yield on the regional scale.

Key words: meteorology, winter wheat, harvest index, model