Migration And Enrichment Characteristics Of Manganese In The Soil-tea Tree System Of Tea Gardens With Different Parent Materials In Guizhou Tea Production Area

Manganese is an essential nutrient element for plants,and parent material,as the material basis for soil formation,has a great influence on the content of Mn in soil.In this paper,the main tea producing area in Guizhou Province is used as the research area,and the soils(leaching layer,sedimentary layer and parent material layer)developed with three parent materials of old weathering crust(Quaternary red clay),sand shale and quartz sandstone were collected respectively.and corresponding samples of different parts(roots,stems,leaves and litter)of the tea tree [Camellia sinensis(L.)O.Kuntze].By comparing the soil profiles of different parent materials and the characteristics of Mn content in each part of the tea plant,the correlation between the Mn content in each part of the tea plant and the soil physicochemical indexes was analyzed,and the factors affecting the migration and accumulation of Mn in the soil-tea plant system were explored.The main results are as follows:(1)The total Mn content in the soil developed from different parent materials is sand shale(666.76 mg/kg)> old weathered crust(583.06 mg/kg)> quartz sandstone(245.89 mg/kg),all of which are lower than those of Guizhou soil.The background value shows that the average content of acid-soluble Mn in the soil developed from the old weathering crust,sand shale and quartz sandstone parent material is 42.15mg/kg,58.19 mg/kg and 23.24 mg/kg,respectively.(2)Manganese has obvious enrichment characteristics compared with Fe,Cu and Zn in soil.The overall enrichment coefficients of Fe,Mn,Cu and Zn in the soil developed from the three parent materials are 0.94,1.22,0.85 and 0.83,respectively..The enrichment frequencies of Fe,Mn,Cu,and Zn are 23.9%,49.8%,10.9%,and10.8%,respectively;the average enrichment coefficients on soils developed from old weathering crust,sand shale and quartz sandstone parent materials are 1.25,1.28 and0.99,and the enrichment frequencies are 55%,47.4% and 28.6%,respectively,all of which indicate that the soil enrichment ability developed from the parent material of quartz sandstone is weaker than that of old weathering crust and sand shale.(3)The magnitude of Mn content in different parts of tea tree was litter(2.55g/kg)>leaf(1.88 g/kg)>stem(0.74 g/kg)>root(0.36 g/kg).Manganese has the characteristics of high transport and strong enrichment in tea plants,in which the average migration coefficient from root to stem is 2.908,and the average migration coefficient from stem to leaf is 2.607;the enrichment coefficients of Mn in roots,stems,leaves and litter are respectively 0.890,2.013,5.194 and 6.499.The average enrichment coefficients of Mn in tea roots are sand shale>quartz sandstone>old weathered crust on different parent materials,and the average enrichment coefficients of Mn in tea stems,leaves and litter are all quartz sandstone>sand shale>old weathered shell.(4)The content of Mn in soil and its morphological characteristics are the main factors affecting the content of Mn in tea trees.The content of Mn in each part of the tea tree is positively correlated with the content of Mn and various forms of Mn in soil.