Effects of combining application of Mg, Zn and Mo fertilizers on leaf biomass and medicinal quality of ginkgo seedlings Phytoremediation Characteristics of the Pb and Cd Contaminated Soils by Ginkgo Seedling The Effect of Cutting Top bud from Ginkgo Seedlings on Different Date Leaf Growth and Medicinal Quality of Ginkgo Seedling with Spraying Mg,Zn,Mo Fertilizers