Abstract:
Drooping wildryegrass (Elymus nutans ) has been widely planted
together with other perennial grasses for rebuilding degraded alpine
meadow atop the Tibetan Plateau. However, the rebuilt sown pastures
begin to decline a few years after establishing. One of the possible
causes for degradation of sown grassland may come from allelopathy of
planted grasses. The purpose of this study was to examine allelopathic
potential of drooping wildryegrass. Three types aqueous extracts
from drooping wildryegrass and its root zone soil were prepared and 5
highland crops and 5 perennial grasses were used as recipient plants.
Drooping wildryegrass exhibited strong allelopathic potential on
germination and seedling growth of 5 crops germination and growth, but
different crops or perennial grasses respond to the extracts
differently. The pieces extract has stronger inhibition than others.
Hulless barley, oat and Chinese fescue were the most affected, while
quinoa and Siberian wildryegrass were the least affected. Drooping
wildryegrass presented less influence on Kentucky bluegrass and
crymophylla bluegrass than on Chinese fescue. It is recommended that the
species combination of mixture for restoration should consider
allopathic effects of the co-seeding and decrease the seeding rate ratio
of drooping wildryegrass. The annual dicot crop quinoa and rape seeds
can be used as alternative subsequent crop for seed field of drooping
wildryegrass monoculture.