Establishment of Prairie Forbs and Grasses after Production in Compacted Media

Abstract

Native prairie plants are believed to grow better in compacted soils than traditional bedding plants. We used 10 species of forbs and grasses to test the hypothesis that establishment in the field would be improved by greenhouse production of seedlings in compacted media and in topsoil as opposed to a peat-based medium. Media were compacted by applying 50 g·cm–2 while filling cells in a tray. Uncompacted controls were simply loose-filled. The seedlings were transplanted into plots that were untilled or tilled. Plants were photographed with a digital camera at different stages and the images were analyzed by computer to estimate growth non-destructively. At the time of transplanting estimated area per seedling was 15 to 140% higher for plants grown in compacted media than in uncompacted for 10 out of 13 species. Preliminary observations indicated that differences between plants from compacted and uncompacted media persisted in the field and that plants grew better in the tilled plots than in untilled. Seedling area was similar after production in topsoil or peat medium and there was no overall difference in the field. Plants from seedlings produced in topsoil were larger than those from peat-based medium in untilled plots but the converse was true for plants in tilled plots.