Skip to main content
ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Research Project #432332

Research Project: Response of Ecosystem Services in Agricultural Watersheds to Changes in Water Availability, Land Use, Management, and Climate

Location: Water Management and Systems Research

2018 Annual Report

Objective 1: Quantify changes in agricultural production and fluxes of water and associated nutrients (N and P) and sediment from field to watershed scales over the next several decades at fine temporal resolutions in response to changes in water availability, land use, management practices, and climate. Sub-objective 1.1. Understand and quantify the effects of variable irrigation practices on crop production responses by assessing genotype x environment x limited-water management (GEM) interactions for different land use, management, and climate scenarios at field to watershed scales. Sub-objective 1.2. Improve estimates of water redistribution and storage by resolving spatial scale issues related to the measurement and simulation of soil moisture in cropland and grassland ecosystems at field to watershed scales. Simulate hydroecology within the SPRB and the Central Plains Experimental Range (CPER) Long-Term Agroecosystem Research (LTAR) site to extend experimental results to larger areas and different management scenarios. Sub-objective 1.3. Understand how the effectiveness of spatially distributed water conservation strategies and agricultural best management practices (BMPs) for nutrient and sediment control vary with landscape position, geographic/geologic characteristics of the field, farm, or watershed, and other factors. Objective 2: Assess key ecosystem services for projected water requirements and water quality targets in the South Platte River Basin, Colorado, at field to watershed scales in response to changes in water availability, land use, management, and climate. Objective 3: Develop and disseminate a web-based geospatial data management system as a repository of data, models, and tools for accelerating collaborative research and facilitating sustainable management of water, nutrients, and sediment.

Objectives 1 and 2 focus on enhancing scientific knowledge for incorporation into the Agricultural Ecosystems Services (AgES) distributed watershed model with subsequent testing and application of AgES. Objective 1 is divided into three sub-objectives integrated from smaller to larger scales, which focus on: (1.1) improved model components for plant modeling of GEM interactions, particularly for irrigated water management, (1.2) soil water modeling emphasizing spatial scaling of soil water and surface runoff in dryland cropping and rangeland systems, and (1.3) simulation of conservation effects over regional watersheds, primarily in Iowa where collaborators have been investigating and monitoring water quality impacts over decadal time scales. In Objective 2, the AgES model will be used to simulate a series of land use, management practice and climate scenarios for hydrologic and water quality ecosystem service indicators in eastern Colorado. Objective 3 involves development of a web-based Geospatial Portal for Scientific Research (GPSR) for technology transfer of geospatial information. GPSR will be used for dissemination of the results of the present project together with broader technology transfer by ARS and collaborators, such as experimental results generated from Long-Term Agricultural Research sites and Climate Hubs.

Progress Report
Objective 1.1: The Unified Plant Growth Model (UPGM) has been tested within the Agricultural Ecosystems Services (AgES) watershed model. Progress toward final deployment of UPGM as a key component of AgES includes: 1) converting UPGM code to Java to facilitate distribution of the Java-based AgES model, 2) enhancing the model by improving carbon partitioning and plant nitrogen responses and improved plant parameters, 3) running AgES/UPGM as part of the Agricultural Model and Intercomparison and Improvement Project consortium examining genetic variations of key physiological traits for extreme high yields, 4) evaluating UPGM for phenological genetics-by-environment-by-management interactions with a manuscript being submitted in FY18, and 5) continued work with the Wind Erosion Predictions System (WEPS) modeling team on restructuring and redesign of UPGM so that it can more readily incorporate recent scientific concepts and approaches and replace the plant growth components of other agency models such as WEPS, WEPP, SWAT, APEX, and ALMANAC. Objective 1.2: The Agricultural Ecosystems Services (AgES) watershed model was developed by ARS scientists in Fort Collins, Colorado collaboratively with researchers at Colorado State University. AgES was used to explore spatial “scaling” of soil water measurements using data from the Drake Farm in Colorado under dryland cropping (primarily winter wheat-fallow rotations in the simulation period 2003-2008). A journal manuscript was submitted entitled, “Effects of spatial resolution and parameter complexity of an agricultural watershed model on simulated hydrology and scaling of soil water” and is being revised following review. Objective 1.2: Following calibration of soil hydrology parameters in AgES, the model was extended to simulate conversion from wheat-fallow cropping to mixed perennial vegetation under the Conservation Reserve Program (CRP). The transition to CRP in 2013-2014 resulted in reduced surface runoff with increased thresholds of rainfall intensity-duration needed to produce runoff. Following full establishment of perennial vegetation, no runoff has occurred at the watershed outlet (edge of field). Objective 1.2: Measurement of soil moisture in space and time at the Drake Farm continued using buried capacitance sensors at multiple depths and landscape positions, and was enhanced using a portable Time Domain Reflectometer (TDR) and two Cosmic Ray Neutron Sensors (CRNS) installed at summit and toeslope positions. Testing and evaluation of the CRNS stations contributes toward ARS application of this technology at multiple sites, including collaboration at the Long-Term Agroecosystem Research network site on the Central Plains Experimental Rangelands and related milestones in future years of this project. Objective 1.3: Components for simulating conservation practice effects in AgES are being enhanced, and a new tile drainage component has been applied to improve simulation of nitrate transport in the Southfork Watershed (SFW), Iowa. This will contribute toward ongoing collaboration with scientists in Ames, Iowa. This collaboration has potentially high impact because simulations of conservation practices with AgES complement and build upon the Agricultural Conservation Planning Framework ( Overall Project Deliverables: Web-based tools and services are being developed and deployed in collaboration with Colorado State University (CSU). A new web framework at CSU called Catena provides a public interface for execution of the Agricultural Ecosystems Services (AgES) watershed model and visualization of its outputs. A prototype of AgES in Catena now runs on the Cloud Services Innovation Platform (CSIP). Essential tools for processing spatial data and generating model inputs are also being developed: Catchment areas delineation (Cadel) analyses the watershed topology using a Digital Elevation Model (DEM) and other spatial layers (e.g., soil and land use) to partition a watershed into Hydrological Response Units (HRUs) and generate the essential HRU and routing files for AgES. The Landuse and Agricultural Management web-Service (LAMPS) generates land use, crop rotation, and tillage management for each HRU. Deployment of LAMPS has been enhanced in CSIP (see Accomplishment #2), and integration of LAMPS into Catena for a graphical is in the initial stage.

1. Innovative cropping and no-till management increase carbon sequestered in dryland soil. Soil organic carbon pools were measured at different landscape positions across a climatic gradient with different cropping systems. Results of this long-term field study conducted by ARS scientists in Fort Collins, Colorado, and Colorado State University showed that active soil carbon pools in dryland agroecosystems can be increased using no-till management and increasing cropping intensity from wheat-fallow, to wheat-corn-fallow, to continuous cropping, to Conservation Reserve Program (CRP) with native perennial grasses under both drought and wet conditions. These findings, published in a special issue of the Journal of Environmental Quality, provide insight into how management practices can enhance soil carbon sequestration rates and improve soil health in water-limited dryland systems.

2. The new Agricultural Collaborative Research Outcomes System (AgCROS) network. ARS scientists in Fort Collins, Colorado contributed to the management of the new Agricultural Collaborative Research Outcomes System (AgCROS) network. Assisted in the development and improvement of the AgCROS portal and continue to work closely with collaborators to populate standardized data reporting templates for the Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet), Resilient Economic Agricultural Practices (REAP), NUOnet (Nutrient Uptake and Outcome network), LTAR (Long Term Agricultural Research), BIOnet, DAPP (Dairy Agriculture for People and the Planet), and AgAR (Agricultural Antibiotic Resistance) databases that are now publicly available in the new AgCROS network. This network will contribute to joint databases that connect the field to the table, by connecting databases in areas ranging from natural resources, to crops and livestock, to human nutrition.

3. New web service identifies the area and dynamics of the U.S. Corn Belt. ARS scientists in Fort Collins, Colorado updated and applied the Landuse and Agricultural Management Practices web-Service (LAMPS) to identify corn intensity at the county level in 48 states for user-defined time periods. The generated maps illustrate the ability to identify and quantify counties growing corn at different intensities (areas of corn), which resulted in a “bulls-eye” of mostly contiguous high intensity Corn Belt counties tapering into lower intensities beyond the traditional Midwest Corn Belt. LAMPS also generated a map of irrigated areas, which helps explain some factors for the Corn Belt dynamics. Recent changes indicate expansion of the Corn Belt to more northern latitudes in the West and pockets in the Southwest and East. This web service provides valuable information to extension agents, consultants, researchers, and government agencies for analyzing spatial and temporal trends in U.S. corn production.

Review Publications
Green, T.R., Kipka, H., David, O., McMaster, G.S. 2018. Where is the USA Corn Belt, and how is it changing?. Science of the Total Environment. 618:1613-1618.
McMaster, G.S., Moragues, M. 2018. Crop development related to temperature and photoperiod. In: R.A. Meyers, Editor-in-Chief, G. Slafer and R. Savin Section Editors, Encyclopedia of Sustainability Science and Technology. Springer-Verlag, Heidelberg, Germany. 20 pp. Book Chapter. doi:10.1007/978-1-4939-2493-6_384-3.
Robertson, A.D., Zhang, Y., Sherrod, L.A., Rosenzweig, S.T., Ma, L., Ahuja, L.R., Schipanski, M.E. 2017. Climate change impacts on yields and soil carbon in dryland agriculture. Journal of Environmental Quality. doi:10.2134/jeq2017.08.0309.
Sherrod, L.A., McMaster, G.S., Delgado, J.A., Schipanski, M.E., Fonte, S.J., Montenieri, R.L., Larson, K. 2018. Soil carbon pools in dryland agroecosystems as impacted by several years of drought. Journal of Environmental Quality. doi:10.2134/jeq2017.09.0371.