根表铁、锰氧化物胶膜在磷不同浓度下对水稻磷吸收的影响

在采用土－砂联合培养和不同水分管理措施形成不同厚度根表铁、锰氧化物胶膜试验的植株上，将植株转移到磷不同浓度的营养液中，研究根表铁、锰氧化物胶膜对水稻磷吸收的影响。结果表明，水稻根表铁、锰氧化物胶膜，特别是铁胶膜受土壤水分状况影响，在长期淹水条件下，根表铁、锰氧化物胶膜较厚，而湿润和干－湿交替处理下形成的胶膜较薄；水稻根表铁、锰胶膜以铁胶膜为主，占胶膜总量的97.63%～99.23%；水稻根表铁、锰胶膜越厚，对介质中磷的吸附量越高，且磷吸附量随介质中磷浓度的增加而增加；根表铁、锰氧化物胶膜对水稻磷吸收的影响取决于胶膜数量(厚度)，当胶膜中等(铁胶膜量为5141mgkg

The effect of ferric and manganese hydroxide cutan on root surface in different phosphorus concentrations on phosphorus uptake by rice plants

Rice plants with ferric and manganese hydroxide cutan on root surface(FMHCRS)in different thickness,which resulted from soil-sand culturing and different management measures on soil water,were transferred to nutrient solution with different P concentrations to study the effect of FMHCRS on P uptake.The results show that the FMHCRS is affected by the soil moisture regime,the cutan is very thick under the long-term submersion condition while it is very flimsy on the condition of humidity or wetting-drying cycle;the majority of FMHCRS is ferric hydroxide cutan(97.63%-99.23%);the amounts of P uptake in the medium increase with the increasing thickness of the rice FMHCRS,as increase with the increasing P concentration in the medium.The effect of FMHCRS on P uptake by rice plants depends on the amount of cutans,when at the moderate level(Fe5141 mg/kg,Mn40mg/kg),the amount of P uptake reaches its maximum.However,either too thick or too flimsy cutan is unfavourable for the P uptake by rice plants.Since the soil moisture regime affects the FMHCRS,the amounts of P uptake by rice plants can be improved by reasonable irrigation.