Crop yield variation trend and distribution pattern in recent ten years
In recent ten years, a perception exists that the agricultural management and crop cultivars have been improved obviously. But the crop yield variation trend due to above reason remain unknown yet. To evaluate the main food crop (maize, soybean and rice) yield trend from 2007 to 2016, the MODIS product (MCD12Q2) was used to extract the mature date of different crops. A two-band variant of the enhanced vegetation index at mature date was applied to establish empirical yield estimation model, coupling with statistical crop yield data. The validation show the estimated yield had accuracy of 90.9%, 91.7% and 83.3%, respectively. The average maize and soybean yield in study area presented increasing trend, but rice yield presented declining. However, maize yield in 22 cities and soybean yield in 19 cities show decreasing trend actually. Through statistical analysis, the crop yield distribution pattern was proved to be almost fixed. Most cities occupies approximate position on the ranking of relevant crop yield. It was demonstrated that some cities, for example Chifeng city, was suitable to develop specific agriculture economy. This paper can be used to give suggestion for agriculture planning and management.