title: Increase of As release and phytotoxicity to rice seedlings in As-contaminated paddy soils by Si fertilizer application.
abstract: Silicon (Si) was shown to be able to reduce arsenic (As) uptake by rice in hydroponic culture or in low As soils using high Si application rates. However, the effect of Si application on As uptake of rice grown in As-contaminated soils using Si fertilizer recommendation rate has not been investigated. In this study, the effect of Si application using Si fertilizer recommendation rate on As release and phytotoxicity in soils with different properties and contents of As was examined. The results show that the concentrations of As in soil solutions increased after Si applications due to competitive adsorption between As and Si on soil solids and the Si concentrations in soil solutions were also elevated to beneficial levels for rice growth. The rice seedlings accumulated more As and its growth was inhibited by Si application in As contaminated/spiked soils. The results indicate that there is an initial aggravation in As toxicity before the beneficial effects of Si fertilizing to rice were revealed when Si application based on fertilizer recommendation rate to As-contaminated paddy soils. Therefore, for As-contaminated paddy soils with high levels of As, the application of Si fertilizer could result in increasing As phytotoxicity and uptake by rice.
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
authors.forename: Chia-Hsing
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
authors.forename: Hsuan-Han
authors.initials: HH
authors.lastname: Huang
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
authors.forename: Chien-Hui
authors.initials: CH
authors.lastname: Syu
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
authors.forename: Tzu-Huei
authors.initials: TH
authors.lastname: Lin
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan. Electronic address: dylee@ntu.edu.tw.
authors.forename: Dar-Yuan
authors.initials: DY
authors.lastname: Lee
mesh_terms: D001151:Arsenic / Q000378:metabolism*; D018533:Biomass; D005308:Fertilizers; D012275:Oryza / Q000378:metabolism*; D012825:Silicon / Q000008:administration & dosage*; D012989:Soil Pollutants / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D001151:Arsenic; D012825:Silicon
keywords: Arsenic; As uptake; Paddy rice; Phytotoxicity; Si fertilizer