Research on the operational application of observed yield of winter wheat from agrometeorological stations in yield prediction
The observed yield of winter wheat from 123 agrometeorological observation stations and the announced yield of winter wheat at county level where the observation station was located were used to integrate the observed yield and announced yield at province and national level by the proportion of winter wheat planting area. And the observed yield and announced yield sequences of winter wheat were compared and analyzed at province and national level. The observed and announced yield of winter wheat at national level were predicted based on the climate suitability index forecast method. The forecast accuracy of different yield sequences were compared and analyzed. The results showed that:(1) the observed yield was large than the announced yield at province level in all provinces, and the difference between the two yields differed markedly. The correlation coefficient between observed and announced yield was good in each province and the correlation passed the significant test except Xinjiang province. The correlation coefficient between observed yield and announced yield at national level reached 0.97, and the observed yield could reflect the characteristic of announced yield. (2) The percent of consistency statistics of trend meteorological yield of observed and announced yield remained good at national level, so it was suitable to carry out yield prediction. While it was unsuitable to carry out yield prediction at province level due to the low percent.(3) The accuracy of different yield sequences in forecasting their own sequences was high and the accuracy of announced yield was higher than the observed yield. The accuracy of the forecast conversion of the announced yield by using the observed yield would be reduced. Conclusively, it is feasible to carry out yield forecast at national level based on the observed yield series because of the real-time, objectivity and representative of the observed yield. At the same time, the new yield series could provide new data support for yield forecast.