Si,Fe and Mn Distributions in Rice （Oryza sativa L.） Rhizosphere of Red Earths and Paddy Soils
摘要
An experiment using rhizobox was conducted to study Si,Fe and Mn distributions in rice rhizosphere of red earths and paddy soils.It was found that Si,Fe and Mn diftributions in rhizosphere of the paddy soils were characterized by a depleted zone around root suface,beyond which the concentrations gradually rost.From lmm layer to 2mm layer the concentrations dropped and then rose again.Whereas Si and Fe in red earths showed no depleted zone but even accumulated zone around root surface.Mn showed an approximately even distribution in each layer and no depletion was found in root surface layers.This indicated that during rice (Oryza sativa L.)plantation,depletion and accumulation of Si,Fe and Mn in rhizosphere were important features of matured red earths by water culture.The distribution changes of Si,Fe and Mn in relation to soil-root interaction are also discussed.