CCPD-Maize: A twenty-year dataset of maize phenology with high spatial resolution in China

The dataset is a long-term, high-resolution maize phenology map for China (China Crop Phenology Dataset–Maize, CCPD-Maize), which contains the phenology maps of maize in 22 provinces of China from 2001 to 2020. The file format is GeoTIFF and the spatial reference is WGS84 (EPSG:4326). The resolution of the phenology maps is 30 m.  We based on a long-term high spatiotemporal resolution fusion dataset of Normalized Difference Vegetation Index (InENVI NDVI dataset) and an annually updated maize distribution dataset (CCD-Maize dataset), used the relative threshold method to identify the maize phenology. Here, the start of the growing season (SOS), the end of the growing season (EOS), the length of the growing season (LOS), the length of the vegetative growth stage (VGS), and the length of the reproductive growth stage (RGS) of maize were generated. The validation of the satellite-based SOS and EOS with the observed maize emergence and maturity dates from agro-meteorological stations showed good accuracy, with R2 of 0.964 and 0.823, respectively.