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
A field study was carried out on the grey disorder in fine-cured tobacco (Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobaccoand...A field study was carried out on the grey disorder in fine-cured tobacco (Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobaccoand dead roots. Grey disorder leaves produced low quality lamina, which was low in N, nicotine, reducedsugar and K contents. In this study’ soil available Mn and leaf Mn contents were in a relatively low level andshould not be an important factor in the occurrence of grey disorder in fine-cured tobacco.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 .
文摘A field study was carried out on the grey disorder in fine-cured tobacco (Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobaccoand dead roots. Grey disorder leaves produced low quality lamina, which was low in N, nicotine, reducedsugar and K contents. In this study’ soil available Mn and leaf Mn contents were in a relatively low level andshould not be an important factor in the occurrence of grey disorder in fine-cured tobacco.
