摘要
分别采集三峡库区开县和涪陵消落带土壤,进行室内模拟淹水实验,研究淹水土壤有机质分解对Fe(Ⅲ)还原行为及磷释放的影响。结果表明,淹水过程中土壤磷向上覆水体迁移,引起上覆水体总磷含量先增加后降低最后趋于平衡。上覆水体总磷的变化与底泥中有效磷呈极显著负相关(p<0.01),且有效磷与无机磷各形态的相关性分析表明磷释放的主要来源是Ca8-P、Al-P和Fe-P。淹水形成的厌氧还原环境导致铁氧化物的还原,无定形铁生成,且二价铁与有效磷呈显著正相关(p<0.05),说明三价铁的还原促进P的释放。淹水过程中,土壤CO2和CH4产生揭示有机质的分解过程,CO2/CH4的比值变化反映淹水土壤无机电子受体的消耗情况,解释Fe3+的还原过程,其与二价铁和有效磷的相关性分析证实有机质分解与铁的还原及磷的释放显著相关,说明有机质分解促进了铁的还原,并进一步促进磷的释放。
The flooded soils from Kai county and Fuling water-level fluctuation zones of Three Gorges Reservoirs areas were collected. The indoor flooding experiment was conducted to study the impact of waterlogged soil organic matter decomposition on the reduction of Fe（Ⅲ） as well as the release of phosphorus. The results showed that soil phosphorus migrated to the overlying water during flooding, which led to increasing of the content of total phosphorus（TP） at the beginning, then decreasing until reaching the balance. Total phosphorus in the overlying water and sediment phosphorus had a significant negative correlation（p〈0.01）, and the correlation analysis of effective phosphorus and inorganic phosphorus showed that the main source of all forms of phosphorus release were Ca8-P, Al-P and Fe-P. Anaerobic environment caused by flooding contributed to the reduction of iron oxide, the formation of amorphous iron, and divalent iron and phosphorus was a significant positive correlation（p〈0.05）, which illustrated the reduction of Fe（ Ⅲ ） accelerated the release of phosphorus. During flooding, the production of soil carbon dioxide and methane revealed the process of organic matter decomposition, the change of ratio of CO2/CH4 showed the consumption of flooded soil inorganic electron acceptor, explained the reduction mechanism of Fe（ Ⅲ ） and the correction analysis between Fe（ Ⅲ ） and Fe（ Ⅱ） as well as Fe（ Ⅲ ） and effective phosphorus verified that the release of phosphorus significantly related to the reduction of organic matter and the reduction of iron, illustrated that the organic matter decomposition promoted the reduction of iron, and further promoted the release of phosphorus.
出处
《水土保持学报》
CSCD
北大核心
2014年第3期271-276,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(411711198)
中国博士后科学基金资助项目(2013M542238)
中央高校基金项目(XDJK2013C151)
西南大学博士基金项目(SWU112098)
关键词
铁还原
磷释放
三峡库区
消落带
iron reduction
phosphorus release
Three Gorges Reservoirs areas
fluctuation zones
