Does the Compositional Change of Soil Organic Matter in Rhizosphere and Bulk Soil of Tea Plant Induced by Tea Polyphenols Have Some Correlation with Pb Bioavailability?

摘要

A pot experiment was conducted to investigate the compositional change of soil organic matter after tea polyphenols (TP) were added to soil and its effect Pb bioavailability.The soils received two Pb added rates,giving a spiked concentration of 0,300 mg/kg and three TP added rates,0,300,600 mg/kg respectively.Adding of TP to Pb polluted soil increased soil biomass carbon (SMBC) and rhizosphere effect of tea plant.Contrary results were found in soil organic carbon (SOC) change in rhizosphere and bulk soil between Pb polluted and unpolluted treatments.The inconsistency of quantity of humic acid (HA) in rhizosphere and bulk soil between Pb polluted and unpolluted treatments might explain above difference of SOC.Fulvic acid (FA) increased with the addition of TP in both rhizosphere and bulk soil,which might be a result of TP transformation.Positive correlations exist between different composition of SOC of rhizosphere soil,and Pb content in different tissues of tea plants.SMBC was negatively correlated with Pb in young leaves and stem.Based on the above results,we may safely draw the conclusion that SOC components have a close relationship with Pb bioavailability and may significantly influence Pb content in different part of tea plant.