Analysis of Crop Phenology Using Time-Series MODIS Data and Climate Data

Abstract:

Understanding crop phenology is fundamental to agricultural production, management, planning and decision-making. In the continental United States, key phenological stages are strongly influenced by meteorological and climatological conditions. This study is conducted in the Midwestern United States to estimate phonological information for corn and soybean. A time series of the Moderate Resolution Imaging Spectrometer (MODIS) Normalized Difference Vegetation Index (NDVI) 16-day composites from 2001 to 2013 was analyzed with the TIMESAT program to automatically retrieve key phenological stages. The temperature data from CRUNCEP was analyzed with R based on the crop model to calculate potential planting date and harvest date by AgroIBIS crop phenology algorithm. With these two methods, start of season (planting date), end of season (harvesting date), and length of growing season from 2001 to 2013 were determined and compared. The results showed a good relationship between estimates derived from satellites and estimates calculated by the crop model formula. Crop progress reports from USDA NASS were used to validate our estimates. We will present the relationship between our estimates and validation data. We will select some specific sites to investigate finer scale local changes of crop phenology during the last decade.