“But when it comes to land-use choices that don’t have revenue expectations and are usually a cost, like most of the best management practices, the tools available for those items are surprisingly rare,” he said. “There’s a little bit of information out there, but having it recent and really germane to what our farmers are dealing with here in Iowa is pretty rare.”
The tools are specific to Iowa, but they provide a framework that other Corn Belt states can adopt and adapt with their own numbers. Other states are applying the potential opportunity cost data from this work in their strategies.
The tools have a decision tree format. Users choose the desired outcome — N, P or sediment reduction — and are asked a series of questions associated with the land being farmed. A list of practices is presented that could fit the farm operation, and clicking each one gives the cost specifications and information about them, with links to more information.
The practices included in the tool are:
Land Use
- Extended rotation
- Contour buffer strip
- Multi-purpose prairie strips
Nitrogen and Phosphorus Management
- The Four Rs: Right source, Right timing, Right rate, Right place
- Conservation tillage
- Cover crop
Edge of Field
- Riparian buffer
- Vegetative filter strip
- Terrace
- Bioreactor
- Re-saturated buffer
“Some practices are really straightforward. Other practices are a little bit more complicated,” Tyndall said.
For example, denitrifying bioreactors are straightforward in use and function but calculating their size requires a series of hydrologic, engineering and physics equations to deal with a certain drainage area. The tool provides a calculator based on one created to determine the size per drainage area and then includes the economics, to determine costs based on size.
Tyndall said all the calculations have been done for the practices. A review process has begun working with Jamie Benning, water quality program manager for ISU Extension and Outreach. Her team will review the tool internally to ensure the calculations and the information provided makes sense, and smooth any design issues on the interface. The review also involves seeking input from contractors who install practices to see if the estimated cost based on surveys is accurate.
To make it interactive, links will be included to related information. If users are interested in bioreactors, for example, they can find the latest information or extension publication and possibly videos of installations or maintenance.
Given the uncertainties of the review process, Tyndall said it’s hard to estimate exactly when it will be ready for public use.
“It’s very likely it will be available by the end of the year, but there may still be some things that we’re working on,” he said.
Source: Iowa State University of Science