Influence of a Changing Climate on Crop Water Use in the Northeast.

Mid-century climate change is expected to significantly impact agriculturally productive areas in the United States Northeastern Seaboard Region (NSR).  Prior work by the authors utilized process-level based crop models in order to evaluate potential changes in the production of corn, potato, and winter wheat due to shifts in seasonal air temperature, rainfall patterns, and atmospheric carbon dioxide concentration. This assessment was conducted at relatively fine sub-county spatial scales throughout the 13 state region and incorporated geospatial trends in physical soil quality, land-use and availability, and crop management practice. Economic yields for all three commodities were shown to be impacted by the changing climate. However, crop resource responses, such as water and nitrogen use, and associated utilization efficiencies, will also be substantially influenced by a changing climate. Since these changes do not necessarily linearly scale with dry matter production, more rigorous quantitative analyses are needed to provide accurate estimates. Studying the impact climate change may have on crop water and nitrogen use is critical in terms of understanding and evaluating realistic adaptation measures, in particular, in-season management options that are dependent on availability of natural resources. The current presentation focuses on simulated geospatial trends in water and nitrogen uptake, and water use efficiency, for the three commodities under current and future climate in the NSR.  An assessment of changes in crop water use efficiency as a result of irrigated versus rain-fed production management will also be explored under current and mid-century climates.