铁膜对水稻根表面电化学性质和氮磷钾短期吸收的影响

通过水培试验研究了水稻根表铁膜对根表电化学性质、根表对NH4+、K+和磷酸根吸附和吸收的影响。结果表明,铁膜降低根表阳离子交换量,使根表zeta电位绝对值减小,说明根表负电荷数量减少。与对照相比,铁膜抑制了水稻根表对NH4+和K+的吸附,但促进了其对磷酸根的吸附。6 h培养实验结果表明,铁膜使水稻对NH4+、K+、H2PO4-的吸收速率分别降低了21.1%、42.7%、59.1%。因此,作为物理、化学屏障或者临时储存库,铁膜抑制了水稻对大量营养元素的短期吸收。

Effect of iron plaque on surface electrochemical properties and short-term N, P and K uptake by rice roots

Effects of iron plaque on surface electrochemical properties of rice roots and adsorption and absorption of NH4 , K and phosphate by the roots were investigated through hydroponic experiments. It was found that the iron plaque formed on rice roots reduced cation exchangeable capacity of the roots and made zeta potential on the roots less negative compared with control, suggesting that the number of negative charges on rice roots became less due to the formation of iron plaque. Iron plaque also inhibited the adsorption of NH4 , K and phosphate by rice roots. Results of 6-h cultivation experiments showed that iron plaque lowered the uptake rate of NH4 , K and phosphate by rice by 21.1%, 42.7% and 59.1%, respectively, as compared with control. In conclusion, functioning as physical and chemical barrier or temporary repository, iron plaque inhibit short-term uptake of macronutrient elements, like N, P and K, by rice plants.