关键词: 高羊茅, 丝茅, 草坪, 根系性状, 土壤性状

Abstract: Imperata koenigii (Retz.) P. Beauv. (speargrass or cogograss) was rated as the most serious weed in tropical and subtropical areas of world. In this study, I. koenigii and Festuca arundinacea were sowed at the same time to form a mixed community. The root traits, such as the density of root length, root dry weight, root volume, and soil traits, such as soil bulk density, soil water content and pH, in the community were consistently determined at 60, 90, 120, 150, 180, and 210 d after sowing. Dynamic analysis of F. arundinacea root and soil traits showed that infestation of I. koenigii had a significant effect on root length density, root dry weight, root volume density of F. arundinacea (P<0.01). In particular, root length density, root dry weight, and root volume density significantly reduced after 60, 90, and 150 d after sowing, separately. The reduced degrees of F. arundinacea root traits affected by I. koenigii were ranked as root volume density>root dry weight density>root length density. I. koenigii also had a significant effect on soil water content, soil bulk density, pH value in different levels of soil (P<0.01). After sowing 60 d, the soil traits of 10~20 cm layer mainly distributed by F. arundinacea root system were significantly affected by I. koenigii as effects extended upward and downward. The effect of duration time on soil traits was ranked as: soil water content>soil bulk density>pH value. The significantly declining meristematic ability of F. arundinacea root due to the infestation of I. koenigii decreased soil water content, weakened soil permeability and increased acidity. Over all, the infestation of I. koenigii reduced root activity and absorption ability of F. arundinacea.

Key words: Festuca arundinacea (tall fescue), Imperata koenigii (speargrass or cogograss), Turf, Root traits, Soil traits