The rhizosphere pH change of pinus koraiensis seedlings as affected by N sources of different levels and its effect on the availability and uptake of Fe, Mn, Cu and Zn

摘要

Dark brown forest soil was collected from the upper 20 cm soil layer in Changbai Mountain Research Station of Ecosystem, Chinese Academy of Sciences. The soil was amended with tow different forms of nitrogen fertilizers: NO_3~- as Ca(NO_3)_2, NH_4~+ s NH_4CI at the concentrations of 50, 100, 200 and 400 mg kg~-1 respectively. The experiment was carried out With 2-yr-old Pinus koraiensis seedings in pot. The pH change of rhizospehre soil and the contents of available Fe, Mn, Cu, and Zn in soil and leaves were analyzed. The result indicted that the addition of NH_4~-N decreased the rhizospehre pH value, while The addition of NO_3~--N increase the rhizosphere pH value in contrast with the control treatment.