INFLUENCE OF SALT CONTENT OF PLIOCENE CLAY SOIL ON THE EMERGENCE OF 6GRASSES

The effects of three soil salinity levels (450, 925, and 1150 mu S/cm) on the emergence of six grasses from a clay badland area of central w estern Italy were investigated. The species were five annuals (Aegilop s geniculata, Brachypodium distachyum, Hordeum maritimum, Parapholis i ncurva, and Parapholis strigosa) growing in the pioneer association Pa rapholido-Artemisietum cretaceae, and the perennial Bromus erectus, th e dominant species of perennial grasslands. The tests were made in pla stic pots filled with soils having different salt contents. A control, conducted in Petri dishes with distilled water, showed a high germina tion percentage for all species but different germination rates. In th e soil tests, the emergence rate of all the species decreased with inc reasing soil salinity. Final emergence percentages were higher than 70 % for all species and all salinities, except for P. incurva and P. str igosa (60 and 46.7%, respectively) at the highest salinity level. B. e rectus showed the lowest emergence rate at all salinities, in line wit h its ecological features.