Distribution Characteristic Of Iron In Tea Tree And The Influence Of The Coupling Characteristics Of Iron And Carbon Under Paddy Field Changing Into Tea Garden Structure In Soil

Iron is the essential elements for tea tree growth, and iron is sensitive metal elements in the soil. The soil organic matter was important part of the material for soil, and responsed sensitively by the agricultural activities, climate and land use changing. The coupling between the soil iron and organic carbon existed in a series of oxidation reduction process. In the experiment, the bleached paddy soil and the tea garden soil and the vegetation as the research object in "the homeland of Famous tea"-Mingshan Country Sichuan Province. The distribution characteristics of iron in vegetation organs, and the relationship between soil total iron (Fet), ferrous iron (Fe2+),free iron (Fed), amorphous iron (Feo), chelated iron (Fep),available iron (Fem) and total organic carbon (TOC), humic acid carbon(HA), fulvic acid carbon(FA), humin carbon were studied in the paddy fields, provide the basis for the rational use and management of tea garden soil resources in Western sichuan. The results showed that:(1) the plant organs iron content all performanced for stem<leaf<root, and tea tree organs iron was obviously higher than rice and rape corresponding organs iron content, tea tree has enriched effection to iron content, but its iron content only have significant correlation to effective iron.(2) Fet have little changes with planting mode changing and the ages of tea tree planting, and have no significant change law in the soil profile. Fe2+content decreased slightly in early tea tree planting years, and then increased later. Meanwhile, Fe2+concentration reduced gradually with soil depth increasing and dropped sharply in bottom in3,7ages tea tree gardens. The change rule of Fed was opposite to Fe+, and Fed decreased with the tea tree planting, increased sharply in30cm and50cm soil profile of in1and6ages tea tree gardens. At the same time the rules of Feo, Fep, Fem were similarly, and their content performed higher in surface soil then in deep soil.(3) In all samples,TOC performance for1year age tea tree garden<paddy field<6years age tea tree garden<7years age tea tree garden<3years age tea tree garden; HA performance for7year age tea tree garden<1years age tea tree garden<paddy field<6years age tea tree garden<3years age tea tree garden; FA performance for1year age tea tree garden<paddy field <6years age tea tree garden<7years age tea tree garden<3years age tea tree garden; humin carbon performance for1year age tea tree garden<6years age tea tree garden<paddy field<7years age tea tree garden<3years age tea tree garden, and all kinds of carbon contents were higher in surface soil(4) pH value have a decresing trend with the planting changes and tea tree planting; Eh value in the soil profile performance for3year age tea tree garden<paddy field<7years age tea tree garden<1years age tea tree garden<6years age tea tree garden.(5) Fet (except the significant correlation between Fet and carbons in6,7years age tea tree garden) and Fed have no significant correlation to all kinds of carbon; The positive relation between Fe2+, Feo, Fep, Fem and all kinds of carbons. But due to the use types and different plant history, the organic carbon had different affection to iron. The main influence fact to Fe2+was TOC in paddy field and6years age tea tree garden, HA in1,3yeas tea garden, humin carbon in7yeas tea garden; At the same time HA have the biggest impaction on Feo in paddy filed and3yeas tea garden, TOC in1,6,7yeas tea garden; Meanwhile in paddy field,1,3yeas tea garden, the main influence fact to Fep is TOC, in6yeas tea garden was humin carbon, in7yeas tea garden was FA; to Fem in paddy field was humin carbon, in1,3,6,7yeas tea garden was TOC.