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By: Maria Smith, HCS-OSU
In our last post, we announced the return of GeoVine, a GIS-based vineyard site assessment tool that is currently maintined by the Virginia Tech Center for Geospaitial Information Technology. This tool is supported for users in Virginia, Maryland, and now Ohio. The webinar on December 15 was recorded and can be viewed here. If, after watching the video and exploring the tool, you still have questions or suggestions for additional parameter estimates, please send your comments to firstname.lastname@example.org. The following write-up will provide my re-cap and experiences using the tool, benefits, and caveats to use.
Temporary site access for Ohio stakeholders: https://cgit04.cc.vt.edu:2002/vineyards/
So, let's get started...
What is GeoVine?:
GeoVine is a tool that aggregates publicly available data provided from regional weather stations, USDA soil surveys, and other databases to provide a broad overview of site suitablity for vineyard plantings. In essence, GeoVine simplifies the task of investigating your site's characteristics. It can provide valuable insights into climatic suitability for grape varieties and highlight factors that may impede the success of a new vineyard.
While GeoVine gives a good generalization of site suitability, it does not provide all site-specific information or recommendations that would be needed for properly preparing a site, such as soil analyses for fertilization/pH amendments and tile drainage recommendations. It is also limited in its ability to determine variety compatibility for your site. You are encouraged to consult with us, your County Extension, and County NRCS services for further details into your site and variety selection.
How to use Geovine?:
Loading the site brings you to this main page. The tool can be used without registering, however, registering an account enables editing of site boundaries and saving of all site vineyard reports.
Fig 1. GeoVine home page. Registration, login, and management of site reports can be found at the top in the red menu bar.
Developing a new vineyard report:
To obtain a new vineyard report, select “Vineyard Manager” in the top menu and click “New Vineyard” from the drop-down list. This page then shows you all current regions where GeoVine is available.
Fig 2. “Create a New Vineyard” page under “Vineyard Management”
Entering your site name or clicking on the state of interest allows you to locate your vineyard either through scrolling or (more easily), entering your address information in the top right corner of the page. Note: the view of the map itself can be changed to show satellite view, streets/roads, and current AVAs by changing the “Basemaps” and “Layers” that are shown.
Fig. 3 Locating your site on the map.
Drawing the boundary
Once you have found your site of interest on the map, you can select out the parcel for which you wish to develop a report by using the “draw new boundary” tool on the left side-menu. This boundary tool allows you to select any area that is a closed polygon, with a single mouse click indicating a new directional change, and a double-click (or click back on the first blue dot) to close the boundary. This boundary can then be edited or deleted if you wish to select a different area or modify the existing area. Note: You can only generate one report per boundary area. Other areas of interest within your sites will require you to create another “new vineyard”.
Fig 4. An example of a closed boundary created using the “draw boundary” tool.
Once you have clicked “done”, you can then generate a report for that area. According to Peter Sforza at CGIT-VT, this can take several minutes depending on the queue for their server use. In my experience, this is usually under 5 minutes, so please be patient with the spinning red ring!
GeoVine features the ability to provide daily forecasts for your site based on the closest regional weather station. This feature is automatically enabled but can be easily be turned off depending on your needs.
Understanding the report
Vineyard site reports contain approximately 18 pages worth of data, data sources, and convenient definitions so that you can interpret your own results. Again, the key to using this resource is to keep in mind that GeoVine output is only as good as the data sources that feed it. While GeoVine provides a very reasonable guide to base decisions, you are the ultimate final say in your site selection, variety selection, and planting preparation. Make sure you are using all of the available resources and references to you before finalizing your decisions.
Fig 5. Example cover page for Vineyard Report output
OK, so let’s review some of the major items to consider when interpreting the output from Geovine, starting from page 1.
- The site selection area is “planar”. Therefore, it does not represent topographical contributions to area. Use an accurate on-site survey for the proposed planting area. You will NOT be estimating correctly using the planar area on the page
- CEC, Bulk Density, organic matter, and pH are estimates from past soil surveys. Depending on previous land use and management, these values may differ. It is always recommended to obtain new soil analyses prior to planting and once every 3 years after planting to maintain your soil conditions for vine health.
- The climate data reflect averages dating back to 1980. Therefore, it will not account for weather extremes that have happened prior to 1980. It is also not site-specific microclimate conditions, which would require an onsite weather station. That means the climate data would not capture the propensity for some issues such as winter cold injury and spring frost, which are very dependent on the topography of your site (this info is included in the report, though!).
- The variety suitability list provided is not exhaustive and does not consider sensitivity to winter extremes (extremes and frequency of them are not provided in the report). The probability for events down to 14 °F are reported but remember that midwinter bud injury does not generally occur until temps < 0 °F in Ohio for the most sensitive Vinifera. Also, the variety list does not take into account your risk tolerance for seasonal variability. That means, in general, some varieties in the report may appear to not attain optimal maturity based on season length in an “average” year for your site, but if you are willing to accept that risk for the vintages that do and have a plan in the winery to deal with suboptimal fruit maturity, then that is your prerogative.
- Slope and land suitability: “Unsuitable” does not necessarily mean unsuitable – less desirable was considered the better term. However, > 15% grade should generally be avoided for planting just from a practicality standpoint.
That said, GeoVine is a very useful tool in determining GENERAL site and variety suitability. I have had a lot of fun playing around with it over the past week or so and have found it informative when considering issues that a grower may encounter with a potential site. Whether you are planting new acreage or are curious about your current site, we encourage you to take the time to thoroughly explore the tool. If you have any questions regarding your output, please do not hesitate to contact us