Analysis and Prediction of the Planting Condition and Progress for Six Major Crops in the United States.

Crop planting dates impact subsequent management decisions and final crop yields. The objectives of this study were to analyze region-specific crop planting conditions and develop a site-specific algorithm for planting initiation and progress. We evaluated the planting conditions and progresses for corn (Zea mays L.), cotton [Gossypium hirsutum (L.)], rice (Oryza sativa L.), sorghum [Sorghum bicolor (L.) Moench], soybean [Glycine max (L.) Merr.], and winter wheat (Triticum turgidum L.) in selected U.S. states. For the five summer crops, earliest planting dates gradually shifted toward later dates with increasing latitude and elevation. The trend was reversed for winter wheat, with the earliest planting shifting to earlier dates from south to north and from low to high elevation. Lowest min soil temperatures in the seven days preceding the earliest planting (planting temperatures) for summer crops generally decreased from south to north and from low to high elevation, while highest max soil temperatures in the seven days preceding the earliest planting (planting temperature) for winter wheat also decreased from south to north and but increased from low to high elevation. Planting temperatures were fitted quadratic equations of duration, latitude, elevation and longitude for each state and each crop, the resulting equations had marginal success in predicting planting temperatures and corresponding earliest planting dates at the county level. Planting progress was predicted based on the planting temperatures and soil wetness conditions at the county level, with state-level progress obtained through integration of county-level progress. The algorithm was marginally successful at state progress prediction. The results could be used for crop production planning and for crop simulations and analyses.