Effects Of Elevated Acid Deposition On Al Rhizosphere Process And Al Distribution Pattern In Tea Plantation

The elevated acid deposition is one of the most important threats in terrestrial ecosystems, which can acidify soil and activate aluminium ions. While tea tree is an acidophilous and aluminum-rich plant. Under the background of global elevated acid deposition, the response process of tea garden aluminum loop, especially the rhizosphere aluminium transformation mechanism of tea tree is unclear.To explore the relationship between the increasing acid deposition and rhizosphere process of aluminum and the aluminum distribution pattern of the tea tree body, the simulation experiments in situ were conducted, which has four treatments(pH2.5, pH3.5, pH4.5, and CK water) and three reiterations. The study focuses attention on the physical-chemical-biological characteristics of the tea garden soil, the rhizosphere effect of aluminum and aluminum distribution pattern in tea tree body, the main results were as follows:(1) The elevated acid deposition improves the contents of total aluminium and extracted aluminium in the surface rhizosphere soil and reduces the contents of total aluminium and extracted aluminium in surface bulk soil to a certain degree. Meanwhile, the elevated acid deposition promotes the total aluminuim and extracted aluminium to rhizosphere soil in tea plantation.(2) The elevated acid deposition is benefit for the HC1-A1to transform into KCl-Al, and accelerates the speed of aluminum KCl-Al, CuCl2-Al and NH4OAC-Al into the surface rhizosphere soil in tea plantation to a certain degree.(3) The elevated acid deposition has a promoting effect on aluminum enrichment of tea tree, as well as concentrating aluminum to mature tea parts especially old leaves, main branches and storage roots in certain situations.In general, the elevated acid deposition significantly changes the transformation process of rhizosphere aluminium in tea plantation and enhances the aluminum content in main parts of tea plant body. Meanwhile, the elevated acid deposition has an obvious coupling effect with the soil organic carbon, total nitrogen and microbial activity, but a weak correlation with soil phosphorus content.