多花黑麦草在酸化铅锌尾矿上的定植和生长

铅锌矿尾矿上设置长喙田菁压青和不压青处理，在此基础上研究多花黑麦草的萌发、生长和重金属积累情况．结果表明，种植长喙田菁改善了尾矿理化性状，尤其是提高了有机质、全N、有效态磷和K的含量．尾矿的强酸性环境(pH<3)是影响黑麦草在其上定植的主要因素．施用石灰可暂时改善尾矿酸度，但实验结束时尾矿酸度几乎完全恢复原状．因此，施用石灰可能只对种子发芽产生作用．大多数情况下多花黑麦草能在尾矿上萌发、生长和定植，并产生较大的生物量(DM1．4～3．2t·km^-2)，表现出对酸性尾矿环境的一定的适应性．与未栽培长喙田菁的对照相比，栽培长喙田菁处理以及栽培长喙田菁并压青处理分别使多花黑麦草的生物量提高了4．8％～39．5％和7．7％～139．5％，其中压青处理又比不压青处理提高了2．7％～75．8％．“长喙田菁-多花黑麦草”植被系列是一个成功的铅锌矿尾矿废弃地复垦的先锋阶段

Establishment and growth of Lolium multiflorum for phyto-remediation of Pb/Zn tailings

Following the cropping of Sesbania rostrata, Lolium multiflorum was cropped as the subsequent species on an acidified Pb/Zn tailings site. As the experimental treatments, S. rostrata issues harvested on the site were removed from the site or buried into the tailings as the green manure. Changes of tailings chemical and physical properties, germination, growth and heavy metal accumulation of Lolium multiflorum were investigated. The results showed that cropping of S. rostrata improved the chemical and physical properties of the tailings, especially for the contents of organic matter, total nitrogen, available phosphorus and available potassium. The strong acidity (pH < 3) in the Pb/Zn tailings was the main factor that limited the establishment of L. multiflorum. The tailings acidity was decreased temporarily by lime application and it seemed to be helpful only for the germination because the strong acidity was restituted in the end of the experiment. In the most cases, L. multiflorum succeeded to germinate, grow and establish on the Pb/Zn tailings, and yielded relatively great biomass (DM 1.4-3.2 t.km-2). Compared to CK (without S. rostrata cropping), cropping S. rostrata increased the biomass of subsequent L. multiflorum by 4.8%-39.5% in case without S. rostrata green manure using and by 7.7%-139.5% in case with the green manure using, and the green manure application resulted in 2.7%-75.8% increment of L. multiflorum biomass. The results proved that the artificial vegetation process using S. rostrata and subsequent L. multiflorum would be a successful pioneer stage for restoration of the Pb/Zn tailings.