ABSTRACT
Sanitary landfilling is the most common method employed in disposing of municipal solid waste (MSW) in many countries of the world (Schrab et al., 1993; Shrive et al., 1994). There has been a trend in recent years toward the use of completed sanitary landfills as parks and golf courses, all of which require establishment ofvegetation (Saint, 1992). However, difficulties in vegetating landfill sites have been experienced over the last decade in many countries (Ettala, 1987; Wong, 1988; Wong and Leung, 1989). Drought stress is one of the major factors limiting plant growth and development on landfill sites which results, at least in part, from the difficulty for water availability arising through the refuse to reach the cover soil during the dry seasons due to the low rate of capillary rise of water (unpublished data). Moreover, the cover soil is usually highly compacted during construction, which limits infiltration and may lead to excessive rainwater runoff. In addition, the shallow root systems that usually developed in landfill sites due to the high concentration of carbon dioxide around roots and the high compaction of soil make the plants even more susceptible to water stress (Chan et al., 1991).
