摘要
在田间条件下,运用土壤溶液原位抽提和毛细管电泳分析等技术,比较了芦竹(Arundo donaxLinn)和香蒲(Typhalatifolia)根表铁氧化物胶膜数量、土壤根际溶液磷质量浓度、根际土和根际溶液pH及根膜比等的差异,阐明了湿地植物根表铁氧化物胶膜对磷素从非根际土壤-根际土壤-根际溶液-根表铁氧化物胶膜-根系的迁移过程的影响以及在磷素净化中的根际调控机制.结果表明,芦竹和香蒲根表铁氧化物胶膜数量(以根系鲜重计)分别为20 170.8和7 640.3 mg/kg.有铁氧化物胶膜沉积的芦竹、香蒲的根际土有效磷含量分别是28.85、34.99 mg/kg;各比其无铁氧化物胶膜增加了46.2%、21.9%.有铁氧化物胶膜沉积的芦竹、香蒲的根际溶液磷质量浓度为0.65、0.56 mg/kg,分别比其无铁氧化物胶膜沉积高9.2%、33.9%.芦竹根表铁氧化物胶膜吸附的磷占根系吸附吸收磷的81.7%,香蒲是85.7%.根表有铁氧化物胶膜沉积的芦竹磷素利用有效性比无铁氧化物胶膜的植株高16.5%,香蒲高31.4%.有铁氧化物胶膜沉积的芦竹和香蒲植株体内磷含量均比无铁氧化物胶膜高.同时,铁氧化物胶膜对磷酸盐的吸附提高了磷酸盐从非根际向根际、固相(根际土壤)向液相(根际土壤溶液)的迁移速率.有铁氧化物胶膜沉积的湿地植物根际土有效磷含量累积,无铁氧化物胶膜沉积的湿地植物根际土有效磷含量耗竭.
In situ micro-suction cups were used to collect samples of soil solution with Arundo donax Linn and Typha latifolia from defined segments at rhizosphere in field.The experiment was conducted to elucidate the contribution of iron plaque while wetland plants were used to remove phosphorus.The reddish iron plaque was observed and measured on the surfaces of roots of Arundo donax Linn and Typha latifolia in the field,20170.8 mg/kg（fresh weight） for Arundo donax Linn and 7640.3 mg/kg（fresh weight） for Typha latifolia were collected.Olsen-P contents of Arundo donax Linn with iron plaque were 28.85 mg/kg,46.2% more than that of without,34.99 mg/kg for Typha latifolia 21.9% more than that of without.The phosphate concentrations in the in situ rhizosphere soil solution of Arundo donax Linn with iron plaque were 0.65 mg/kg,9.2% more than that of without,0.56 mg/kg for Typha latifolia,33.9% more than that of without.The phosphorus contents adsorbed by iron plaque were 81.7% for Arundo donax Linn and 85.7% for Typha latifolia of the wetland plants with iron plaque.Phosphate use efficiency of Arundo donax Linn with iron plaque was 16.5% more than that of without,31.4% for Typha latifolia.The contents of phosphorus of single plant of the two wetland plants with iron plaque are higher than that of without.Due to adsorb phosphate with iron plaque,the transfer speeds of phosphate from non-rhizosphere to rhizosphere and from soil to soil solution are increasing.The phosphorus contents with iron plaque accumulated at rhizosphere and depleted at rhizosphere without iron plaque of Arundo donax Linn and Typha latifolia.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2010年第3期781-786,共6页
Environmental Science
基金
国家自然科学基金项目(30570340)
"十一五"国家科技支撑计划项目(2006BAC01A13)
长江学者奖励计划项目
关键词
湿地植物
铁氧化物胶膜
根际溶液
磷素吸收
磷素利用有效性
wetland plants
iron plaque
rhizosphere soil solution
phosphate uptake
phosphate use efficiency
