Bluff prairie soil study at Pleasant Valley Conservancy by the USDA-NRCS

Last Tuesday we had a visit from USDA-NRCS soil scientists who are doing a detailed study on soil/plant relationships on bluff prairies in the Driftless Area. This project, under Soil Scientist Peter Hartman, is correlating soil characteristics of bluff prairie plant communities in Wisconsin, Minnesota, Iowa, and Illinois. Our site was selected as one of a number of Wisconsin State Natural Areas.

Kathie and I were happy to contribute our small bit to this extensive research project. We always learn something which has the potential to help us better manage our restoration work.

I was especially interested in the nature of the soil on this bluff prairie. The first photo below shows the lush vegetation on the day of sampling (about two months after the spring burn). Although right after a burn the soil surface (middle photo) looks very bare and rocky, the NRCS researchers were able to easily dig a sampling pit. Also, the long metal probe seen erect at the right side of the top photo could be pounded (with force) all the way to the hilt (at least 7 feet). Thus it is understandable that the prairie grass roots can grow deep into the terrain and obtain moisture.

NRCS crew sampling at one of their transect points on the Pleasant Valley Conservancy bluff prairie

The rocky terrain in the photo below is typical of the south-facing slope of our bluff prairie. I had always assumed (erroneously) that the soil depth here was very shallow.

Typical rocky soil on the south-facing slope. Photo taken the day after a spring burn.

Given the depth of the soil, it is reasonable that the grasses grow tall and lush.

Lush tall grass typical of the bluff prairies. The species are principally Indian grass and little blue-stem.

We look forward to receiving the final report from this interesting study.