Study On Detoxic Aluminium And Promotion Of Ginkgo Growth By Phosphorus, Magnesium, Calcium And Silicon

"416-C"optimal regression design was used to study on detoxic aluminium and promotion of Ginkgo growth by P,Mg,Ca and Si. The results were showed as follows:1 .In this study, the application of P could increased the soil pH value and decreased the content of soil exchangeabled Al .It also could decrease the absorption of Al and reduce Al toxicity . Appropriate amount of P application could promote the growth of Ginkgo ,while excessive amount of P application would influence the absorption of other elements which would make the Ginkgo off the balance of nutrition then decrease the growth of Ginkgo.2. MgCh decreased the soil pH value and increased the content of soil exchangeabled Al, but Mg could reduce the Al content in Ginkgo and then relieve the toxicity of Al by the way of resistant effects .The growth of Ginkgo could be promoted by applied appropriate amount of Mg ,but excessive amount of Mg application would influence the absorption of other elements which would make the Ginkgo off the balance of nutrition and decrease the growth of Ginkgo.3. CaCl2 decreased the soil pH value and raised the content of soil exchangeabled Al. but Ca could reduce the Al content in Ginkgo and then relieve the toxicity of Al through the way of resistant effects .The growth of Ginkgo could be promoted by being applied appropriate amount of Ca ,but excessive amount of Ca application would affect the absorption of other elements which would make the Ginkgo off the balance of nutrition and decrease the growth of Ginkgo.4. In this study, the application of Si could raise the soil pH value and lower the content of soil exchangeabled Al .It also could decrease the absorption of Al and reduce Al toxicity by lowering the soil Al activity, thereby, the toxicity of Al could be relieved. At the same time ,as a helpful element ,Si was able promote the growth of Ginkgo.5. In this study, mutual effects of P and Si could raise the soil pH value and reduce the content of soil exchangeabled Al .It also maked Ginkgo absorb less Al and then decreased the Al content of Ginkgo in roots ,stems and leaves, mutual effects of P and Si have the positive compound effect on Al content of Ginkgo and promoted the growth of Ginkgo.6. In this study, mutual effects of P and Ca had the positive compound effect on the growth of Ginkgo at low concentration ,but had negative compound effect at high concentration, mutual effects of Si and Ca had the positive compound effect on the growth of Ginkgo7.On circumstances of applied MgCl2 and CaCl2 ,the optimal fertilize project was obtained: P1.33 (0.627g.kg-1), Mg0.53 (0.194 g.kg-1), Ca0.13 (0.324g.kg-1),Si1.75 (0.553 g.kg-1) .