Effects of Nitrogen Fertilizer on Growth of Indigofera pseudo-tinctoria in Kyongseodong Waste Landfill, Incheon

Effects of nitrogen addition on the growth of Indigofera pseudo-tinctoria (Leguminosae) in the waste landfill site was investigated. Nitrogen fertilization in the nitrogen poor soils of waste landfill may influence the growth of nitrogen fixing plants beneficially or detrimentally. When I. pseudo-tinctoria was fertilized with three different levels of nitrogen, the coverage of plants treated with 46 g N/$m^2$ and 460 g N/$m^2$ was significantly less than that of plants treated with 23 g N/$m^2$. The growth rates of plant height treated with 46 g N/$m^2$ and 460 g N/$m^2$ were significantly less than those of plants treated with 23 g N/$m^2$. The growth rates of plant diameter treated with 46 g N/$m^2$ and 460 g N/$m^2$ were significantly less than those of plants treated with 23 g N/$m^2$. Dry weights of whole plants in control sites were higher than those of all the others nitrogen treatment sites. Nodule numbers were higher in control plants than those of plants in all the other nitrogen treatment sites. It is suggested that nitrogen fertilizer addition over 23 g N/$m^2$ affect the growth of some nitrogen fixing plants, such as I. pseudo-tinctoria, negatively.