Comparison of Spatial Models for Corn Planting Date and Crop Maturity in Mississippi.

Mississippi’s shift in cropping system dominance from upland cotton (Gossypium hirsutum L.) to corn (Zea mays L.) has caused variably-scaled challenges (at the field-, farmscape-, and regional-scales) for producers and other crop care professionals. Dramatic shifts in crop sequences, planting intensities, and weather patterns have produced inter-related complications associated with the initiation of planting. Ancillary knowledge gaps include: risk assessment determinations, maturity dates (based on growing degree days), and gauging potential yield penalties for continuous production. Geospatial integration of a 3-year corn production footprint (derived from 2013-2015 Cropland Data Layers) with a series of updated temperature-based planting date probability maps enables farmers and other crop professionals to adapt management strategies, minimize risk, and improve farm-gate earnings. The 3-year corn production footprint occupies close to 60% of Mississippi’s harvested land base. Over half of the counties in the Delta have invested between 60-85% of their arable land in corn across the 3-year study interval. Comparison of risk probability maps generated from interpolated weather station point data (N=330) versus Parameter-elevation Relationships on Independent Slopes Model or PRISM-derived-data maps has revealed 2-3 week delays in corn planting dates for two areas in the southern half of Mississippi. Econometric models suggest higher premiums for early corn harvests (7-21d); these vary from $3.95-$4.00/bu. Based on PRISM data models (at a resolution of 16 km²), spatial analysis indicates 17% of the statewide acreages could advance planting dates 1-3 weeks at a very low risk of 10%. Decision-support models that integrate time to maturity (utilizing growing degree days) with optimal planting date intervals are the next logical steps to help producers maintain a competitive edge in corn commodity markets.