Abstract
Establishment and management of North American prairie grasses by field sowing was investigated at the Royal Horticultural Society Garden at Wisley, Surrey, in Southern England. Untreated seed of little bluestem (Schizachyrium scoparium (Michx.) Nash); indian grass (Sorghastrum nutans (L.) Nash); and prairie dropseed (Sporobolus heterolepis (A.Gray) A.Gray.) was sown in May 1997 at 550 seeds/m2 onto topsoil plots (control), topsoil with charcoal mulch, and topsoil covered with transparent, perforated crop polyethylene post sowing. Highest percentage emergence was recorded in the clear polyethylene mulch followed by the charcoal mulch. Weed competition was managed by cutting to 75 mm (≅ 3 in) above the soil surface. Dry weight of prairie grass seedlings in October 1997 was strongly negatively correlated with percentage weed cover in June 1997. Despite the weed competition, on plots where sufficient seedlings survived, Schizachyrium and Sorghastrum were eventually able to dominate Agrostis stolonifera, the most abundant weed, when burnt annually in April. No regeneration of prairie grasses from self-sown seed was observed within the experimental treatments over an 8 year period. The application of this research to more sustainable horticultural practice in urban landscapes is discussed.
Drought changes and the mechanism analysis for the North American Prairie
