NUGGET

With funding from the U.S. Department of Agriculture SBIR Program, Applied Geosolutions, LLC has developed the Nutrient and Greenhouse Gas Evaluation Tool (NUGGET), an early version web-gis prototype that has been designed for estimating and analyzing nutrient releases to air and water from agricultural managements. End users of prototype are rapidly filtering in and include crop consultants, farm managers, natural resource mangers and policy makers. To date, NUGGET is fully functional and is being tested for site-level locations in Merced County, California.

At the center of NUGGET lies the Denitrification-Decomposition (DNDC) soil biogeochemical model, which is designed to assess the impact of management strategies on the fate of nitrogen (N) and carbon (C) in agro-ecosystems (Li et al. 1992). DNDC integrates crop growth processes with soil biogeochemistry. The model tracks crop physiological processes, water stress, and N stress, while accurately modeling important plant-soil processes related to N and C cycles, including mineralization, ammonification, ammonia volatilization, nitrification, denitrification, N uptake, and leaching. To track the impacts of cropping practices on N and C cycling, DNDC includes detailed algorithms to quantify the effects of crop rotation, manure amendment, tillage, fertilization, irrigation, flooding, weeding, and grazing. DNDC can be applied at various scales, ranging from site-specific applications to quantify within-field variability to county and regional scales to account for differences in environmental conditions and management practices.

The main goal behind the NUGGET concept is to enhance the information used by planners and decision makers working to evaluate agricultural management strategies and their associated environmental impacts. At present, farmers and crop consultants must make management decisions within a regulatory environment that is becoming more restrictive and complex. Regulators are forced to make policy recommendations without sufficient understanding of the environmental processes they are attempting to regulate. In short, evaluating alternative management strategies that account for the broad variability in agro-ecosystems can be difficult given the complex processes impacting soils and crops within climatic conditions and farming practices. Dynamic, process modeling can be an effective tool for assisting farmers in effective management strategies to enhance profitability while protecting the environment.

Prior to this project, DNDC remained a basic research tool and was not designed for specific agricultural management applications. However, with the development of the NUGGET prototype, DNDC is now more accessible and easy to use, particularly for non-technical candidates. At this time, the NUGGET prototype consists of user-interactive web framework built around the DNDC model. Site navigation is performed through user-interactive web mapping of agricultural site locations and easy-to-navigate web forms that illustrate model input parameters (including soils, climate, and crop types). Such web components allow end users to select a site of interest and view/modify model-site input parameters. End users can also discriminate on the use of a series of crop management methods of which include detailed parameter settings for crop rotations, manure amendment, tillage, fertilization, irrigation, flooding, weeding, and grazing. After reviewing model inputs, with a simple mouse click, end users can then execute the DNDC model and view results quickly in the form of time series plots and tables. Results allow users to inspect and track specific cropping practices and the corresponding impacts on N and C cycling.

We anticipate our NUGGET prototype will be a valuable contribution toward developing agricultural management strategies that are environmentally responsible and sustainable and are also economically viable for growers. Examples strategies include efficient use of water and fertilizer resources, enhancement of soil organic carbon content and accounting for carbon sequestration, and minimization of nutrient and pesticide leaching, ammonia volatilization, and greenhouse gas emissions.



Figure 1: NUGGET Framework diagram





Figure 2: Flow diagram for the NUGGET system. In this example flow diagram for manure applications, the general flow of the system starts with user selecting the location of the farm for model simulations using a dynamic map navigation system, like Google Maps. Once the location has been selected, default climate and soils data from the GIS are retrieved and shown to the user in the web application. User can then modify the defaults as needed. With a series of web menus, the user defines the management system of the farm. After all inputs are selected, DNDC run on the server. Database system records all inputs and model outputs in the Postgres/PostGIS database. Users then use the web reporting and data visualization system to create output products, maps, and reports.

Applied GeoSolutions, LLC 87 Packers Falls Road, Durham, NH 03824 Phone 603-292-5747 | Fax 413-714-1051 | Email: info@agsemail.com