三峡库区消落带紫色潮土磷形态转化过程  

Transformation Processes of Phosphorus Forms in Purple Alluvial Soil of Riparian Zone of the Three Gorges Reservoir

作　　者：何立平[1,2] 兰波 林俊杰 段林艳[1] 廖雨涵 徐正佳 HE Liping;LAN Bo;LIN Junjie;DUAN Linyan;LIAO Yuhan;XU Zhengjia(Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir,Chongqing Three Gorges University,Chongqing 404100,China;Collaborative Innovation Center of Ecological Environment Protection and Disaster Prevention in the Three Gorges Reservoir Area,Chongqing Three Gorges University,Chongqing 404100,China)

机构地区：[1]重庆三峡学院,重庆市三峡库区水环境演变与污染防治重点实验室,重庆404100 [2]三峡库区生态和灾害防治重庆市协同创新中心,重庆404100

出　　处：《环境科学研究》2021年第8期1952-1960,共9页Research of Environmental Sciences

基　　金：重庆市教委科学技术研究项目(No.KJQN201801233,KJZD-K201801201);三峡库区可持续发展研究中心开放基金项目(No.18sxxyjd11)。

摘　　要：磷形态转化过程是决定消落带土壤磷素向三峡水库释放的关键.以三峡库区消落带紫色潮土为研究对象,在落干和淹水条件下对土壤进行培养,采用修正的Hedley连续分级提取法分析土壤磷形态含量变化,探讨落干和淹水条件下消落带土壤磷形态转化速率及转化过程.结果表明:落干期,碳酸氢钠提取态有机磷(NaHCO_(3)-Po)和氢氧化钠提取态无机磷(NaOH-Pi)的转化速率分别由-6.27和-1.78 mg(kg·d)逐渐增至-0.69和-0.21 mg(kg·d),其在非残渣态磷中的占比分别减少了21.58%和5.95%;相反,水溶态磷(H_(2)O-Pi)和碳酸氢钠提取态无机磷(NaHCO_(3)-Pi)的转化速率分别由2.07和1.74 mg(kg·d)逐渐减至0.43和0.42 mg(kg·d),其占比分别增加了13.50%和13.41%.淹水期,NaHCO_(3)-Pi、NaHCO_(3)-Po和氢氧化钠提取态有机磷(NaOH-Po)的转化速率分别由-1.84、-4.98和-1.72 mg(kg·d)逐渐增至-0.26、-0.55和-0.12 mg(kg·d),其占比分别减少了9.12%、19.33%和4.03%;相反,H_(2)O-Pi、NaOH-Pi和盐酸提取态磷(HCl-Pi)的转化速率分别由4.51、2.00和0.47 mg(kg·d)逐渐减至0.63、0.22和0.05 mg(kg·d),其占比分别增加了28.83%、2.46%和1.18%.可见,落干期NaHCO_(3)-Po和NaOH-Pi均向H_(2)O-Pi和NaHCO_(3)-Pi转化;淹水期NaHCO_(3)-Pi、NaHCO_(3)-Po和NaOH-Po均向H_(2)O-Pi、NaOH-Pi和HCl-Pi转化.落干期和淹水期,NaHCO_(3)-Po均是消落带H_(2)O-Pi的主要来源.因此,降低NaHCO_(3)-Po含量能够有效减小消落带土壤磷素在雨水淋溶及淹水条件下向三峡水库的释放.Soil phosphorus(P)can be transformed into various forms during the continuous dry-wet cycles,which is a critical process of soil P release in the riparian zone of the Three Gorges Reservoir.Therefore,the purple alluvial soils were collected and incubated under the drying and flooding conditions to explore the transformation processes and rates of soil P forms in the riparian zone of the Three Gorges Reservoir.The soil P forms were analyzed using the modified Hedley phosphorus sequential fractionation method.During the drying period,the transformation rates of soil sodium hydrogen carbonate extraction organic P(NaHCO_(3)-Po)and sodium hydrate extraction inorganic P(NaOH-Pi)increased from-6.27,-1.78 mg(kg·d)to-0.69,-0.21 mg(kg·d),respectively,and the proportions of NaHCO_(3)-Po and NaOH-Pi content in ex-Residual-P decreased by 21.58%and 5.95%,respectively.Contrarily,the transformation rates of soil water-soluble P(H_(2)O-Pi)and sodium hydrogen carbonate extraction inorganic P(NaHCO_(3)-Pi)decreased from 2.07,1.74 mg(kg·d)to 0.43,0.42 mg(kg·d),respectively,and the proportions of H_(2)O-Pi and NaHCO_(3)-Pi content in ex-Residual-P increased by 13.50%and 13.41%,respectively.During the flooding period,the transformation rates of NaHCO_(3)-Pi,NaHCO_(3)-Po and soil sodium hydrate extraction organic P(NaOH-Po)increased from-1.84,-4.98 and-1.72 mg(kg·d)to-0.26,-0.55 and-0.12 mg(kg·d),respectively,and the proportions of NaHCO_(3)-Pi,NaHCO_(3)-Po and NaOH-Po content in ex-Residual-P decreased by 9.12%,19.33%and 4.03%,respectively.However,the transformation rates of H_(2)O-Pi,NaOH-Pi and soil hydrochloric acid extraction P(HCl-Pi)decreased from 4.51,2.00 and 0.47 mg(kg·d)to 0.63,0.22 and 0.05 mg(kg·d),respectively,and the proportions of H_(2)O-Pi,NaOH-Pi and HCl-Pi content in ex-Residual-P increased by 28.83%,2.46%and 1.18%,respectively.In conclusion,NaHCO_(3)-Po and NaOH-Pi tended to be transformed into H_(2)O-Pi and NaHCO_(3)-Pi during the drying period,while NaHCO_(3)-Pi,NaHCO_(3)-Po and NaOH-Po were mostly transfo

关 键 词：落干期 淹水期 水溶态磷 Hedley连续分级提取法 转化速率 

分 类 号：X142[环境科学与工程—环境科学]