Location: Agricultural Systems Research Unit
Project Number: 3012-61660-007-00
Start Date: Oct 01, 2013
End Date: Dec 31, 2015
RZWQM2 (a RZWQM-DSSAT4.0 hybrid) and GPFARM-Range process-level models will be used in this study. Typical crop and range livestock management systems will be selected at cooperating ARS locations: Fort Collins, CO, Akron, CO, Bushland, TX, Sidney, MT, Pendleton, OR and Pullman, WA for cropping systems, and Cheyenne-WY, Miles City-MT, and Woodward-OK for range-livestock systems. Scientists at the selected locations will collect minimum datasets (e.g., weather, soil, and crop information) needed for RZWQM2 or GPFARM-Range models, and then work with ASRU scientists to calibrate and evaluate the models. The models will then be validated by comparing the model predictions (e.g., crop production, evapo-transpiration, N uptake, soil moisture, and etc.) against measured data not used in the calibration or in another location. Once the model has been satisfactorily validated for available experimental data at a location, it will be used to extend results for a longer duration using historical and projected climate-change weather conditions (down-scaled from climate change model) and for other important soil types in the surrounding area of the location. The model will then be applied to propose alternative crop and grazing management scenarios. Promising alternative management scenarios derived from the models will be the subject of future field testing. The effects of high CO2 and high temperature on plant growth under possible global change conditions will also be examined for interactions and indirect effects on water and nitrogen uptake. We will compare our RZWQM2 model with DSSAT, Hybrid Maize (university of Nebraska), and MAIZESIM (ARS-Beltsville) models for response to water stress levels, using the 6-years’ experimental data for different water levels at Greeley, CO, as well for response to climate change scenarios for two locations in Colorado (Greeley and Akron) provided by the AgMIP climate group and by the NCAR group. Based on the results, we will improve our model for responses to water, temperature, and their interactions. We will make the results of climate scenario simulations for Colorado available to the AgMIP economic modeling group for extrapolating the results to regional scale, and to other AgMIP groups.