Location: Rangeland Resources & Systems Research
Project Number: 3012-61660-008-04-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2014
End Date: Aug 31, 2019
The longer term goal of this cooperative research project between USDA-ARS and Colorado State University (CSU) is to inter-compare agricultural system models and foster improvements in these models to increase their capability to utilize data from climate scenarios in evaluating the effects of climate change on agriculture and natural resources, as part of AgMIP (the Agricultural Model Inter-comparison Project). A major current objective of this international AgMIP project is to compare multiple crop system models with common datasets to identify the best scientific approaches (and knowledge gaps) for simulating the effects of climate change variables of temperature, CO2, water, and their interactions on natural resources processes and plant growth. The use of these approaches will improve the assessment of climate change effects on natural resources and crop production, and identify adaptations to climate change. Our focus in this cooperative research will be on comparing different approaches in major current models for simulating climatic and water effects on production and soil carbon storage processes in different cropping systems and management practices, and identify and improve the science of these natural resource processes for improved assessments and enhancing production and soil carbon. Specific longer-term objectives are to: 1) identify soil water, soil carbon, and plant growth modules across models that contribute to the best fit with the experimental data and identify the best approaches to simulate the process and its interaction with temperature and management regimes; 2) learn from the comparisons to further improve science for the processes in the current models; 3) improve simulation of water-temperature-CO2-N interactions and assist in exploring management adaptations to limited water and climate change to maintain production and soil carbon in the Central Great Plains. Specific objectives (Statement of Work) for the initial funds being provided for collaborative research are to work with ARS to: 1) obtain modules for effects of temperature, CO2, water, and their interactions on soil carbon (and nitrogen) from major existing crop system models (Daycent and DNDC, and possibly other models such as DSSAT, Cropsyst, APSIM) and link them to the ARS crop system model RZWQM, preferably in the Object Modeling System (OMS); 2) obtain the quality-checked comprehensive experimental datasets available from the AGMIP team or experimental locations, containing needed measurements of above processes; 3) Compare the performance of different models and modules, with a focus on soil water, soil C, and crop productivity results against the experimental data.
The RZWQM model developed by ASRU has the state-of-science approaches to simulate soil water, ET, crop growth (DSSAT crop modules), energy balance, soil carbon, and management practices. We will first identify the process modules in the RZWQM model that are affected by the climate change and water variables, preferably within the Object Modeling System (OMS). We will also obtain such process modules from other AgMIP models and literature. Then we will recreate the full models with various alternatives of process modules to compare their performance with respect to the experimental data from various locations. The process modules will include carbon-nitrogen and water dynamic processes as influenced by climatic variables and their interactions for various cropping- management systems and temperature-rainfall regimes. The best modules will be identified and shared among AgMIP groups and other collaborators for broad dissemination. Initially, experimental datasets from Akron, Sterling, Stratton, and Walsh Colorado will be used for inter-comparison and shared with other AgMIP collaborators. Datasets from other locations in the Great Plains (e.g., Mandan ND) and other AgMIP groups will be added into the database. The inter-comparisons across locations will also involve temperature-water-management interactions in various cropping and management conditions on production and soil carbon. The results of the applications of improved science models to simulate effects of water and climate change on crop production and soil carbon in the Great Plains will be provided to the AgMIP economic modeling team for improved economic calculations.