Mn and Fe are two important micronutrients of paddy soils derived from red earths. Rice (Oryza sativa L.) or-anging physiological disease in newly reclaimed red earths is related to Fe toxicity. There have been consid...Mn and Fe are two important micronutrients of paddy soils derived from red earths. Rice (Oryza sativa L.) or-anging physiological disease in newly reclaimed red earths is related to Fe toxicity. There have been considerable stud-ies on Mn and Fe counteraction, but influence of Mn and Fe counteraction on rice oranging physiological disease stillremains unknown.This paper is to study, using two soils from USA and China respectively, the relationship between Mn and Fecounteraction and the physiological disease. Analysis for water soluble and extractable Fe and Mn showed thatMn/ Fe ratios of the red earths were lower than those of the paddy soils. Fertilizing with Mn raised Mn/ Fe and re-duced oranging leaves, improved growth and increased yields. Analysis with electron probe showed that Mn treat-ment had less Fe deposit in root epidermis and more Ca and Si in roots.The results indicated that fertilizing with Mn could correct Fe toxicity. How to apply Mn and Fe counteractionin practice is worth further studying .展开更多
An experiment using rhizobox was conducted to study Si, Fe and Mn distributions in rice rhizosphcre of red earths and paddy soils. It was found that Si, Fe and Mn distributions in rhizosphere of the paddy soils were c...An experiment using rhizobox was conducted to study Si, Fe and Mn distributions in rice rhizosphcre of red earths and paddy soils. It was found that Si, Fe and Mn distributions in rhizosphere of the paddy soils were characterized by a depleted zone around root surface, beyond which the concentrations gradually rose. 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.展开更多
文摘Mn and Fe are two important micronutrients of paddy soils derived from red earths. Rice (Oryza sativa L.) or-anging physiological disease in newly reclaimed red earths is related to Fe toxicity. There have been considerable stud-ies on Mn and Fe counteraction, but influence of Mn and Fe counteraction on rice oranging physiological disease stillremains unknown.This paper is to study, using two soils from USA and China respectively, the relationship between Mn and Fecounteraction and the physiological disease. Analysis for water soluble and extractable Fe and Mn showed thatMn/ Fe ratios of the red earths were lower than those of the paddy soils. Fertilizing with Mn raised Mn/ Fe and re-duced oranging leaves, improved growth and increased yields. Analysis with electron probe showed that Mn treat-ment had less Fe deposit in root epidermis and more Ca and Si in roots.The results indicated that fertilizing with Mn could correct Fe toxicity. How to apply Mn and Fe counteractionin practice is worth further studying .
基金Project supported by the National Natural Science Foundation of Chinathe Laboratory of Material Cycling in Pedosphere.Academia Sinica.
文摘An experiment using rhizobox was conducted to study Si, Fe and Mn distributions in rice rhizosphcre of red earths and paddy soils. It was found that Si, Fe and Mn distributions in rhizosphere of the paddy soils were characterized by a depleted zone around root surface, beyond which the concentrations gradually rose. 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.
