Impacts of 33-yr of application of S-containing and Cl-containing chemical fertilizers on rice （Oryza sativa L.） yield and its components were investigated in a red paddy field experiment,south China.The treatments ...Impacts of 33-yr of application of S-containing and Cl-containing chemical fertilizers on rice （Oryza sativa L.） yield and its components were investigated in a red paddy field experiment,south China.The treatments included：1） adding 302 kg SO42--S ha-1 yr-1 with application of （NH4）2SO4-,K2SO4,and calcium superphosphate （SO42-）;2） adding 56 kg SO42--S and 176 kg Cl ha-1 yr-1 with application of urea,calcium superphosphate,and KCl （Cl-＋SO42-）;3） adding 516 kg Cl ha-1 yr-1 with application of NH4Cl,KCl,and KH2PO4 （Cl-）.Under each treatment,the applied N,P,and K nutrients were controlled at conventional rates of 150 kg N ha-1 yr-1,75 kg P2O5 ha-1 yr-1,225 kg K2O ha-1 yr-1,respectively.Under the S-containing fertilizer application,soil SO42--S content showed a first increasing then decreasing trend with years,and was significantly negatively correlated with annual rice yield.Average annual yield significantly declined in an order of Cl-,Cl-＋SO42-,and SO42-.Under the Cl-treatment,soil SO42--S content was maintained at about 26.5 mg kg-1,not showing deficiency.From 1990 to 2000,rice yield declined rapidly under the SO42- treatment,and was significantly lower than that under the Cltreatment.After then,there was no significant difference in yield among the treatments.Our results demonstrated that long-term application of S- containing fertilizer could result in excessive accumulation of SO42--S in the red paddy soils of south China,therefore producing a certain threat to rice growth.The Cl- containing fertilizer could be relatively safe.展开更多
Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismu...Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO_(2)RR conditions. A synthetic approach is developed to electrochemically convert Bi^(O)Cl into Cl-containing subcarbonate(Bi_(2)O_(2)(CO_(3))_(x)Cl_(y)) under operando CO_(2)RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) via a cathodic potential-promoted anion-exchange process. The operando synthesizedBi_(2)O_(2)(CO_(3))_(x)Cl_(y) can tolerate-1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi_(2)O_(2)CO_(3),the formation of metallic Bio occurs at-0.6 V versus RHE. At-0.8 V versus RHE, Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) can readily attain a FEHCOO-of 97.9%,much higher than that of the pure Bi_(2)O_(2)CO_(3)(81.3%). DFT calculations indicate that differing from the pure Bi_(2)O_(2)CO_(3)-catalyzed CO_(2)RR, where formate is formed via a *OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of H COO-over Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) has proceeded via a *COOH intermediate step that only requires low energy input of 2.56 eV.展开更多
基金supported by the Central Public-Interest Scientific Institution Basal Research Fund,China (2008-4)the National Key Technologies R&D Program of China (2006BAD05B09,2006BAD02A14)
文摘Impacts of 33-yr of application of S-containing and Cl-containing chemical fertilizers on rice （Oryza sativa L.） yield and its components were investigated in a red paddy field experiment,south China.The treatments included：1） adding 302 kg SO42--S ha-1 yr-1 with application of （NH4）2SO4-,K2SO4,and calcium superphosphate （SO42-）;2） adding 56 kg SO42--S and 176 kg Cl ha-1 yr-1 with application of urea,calcium superphosphate,and KCl （Cl-＋SO42-）;3） adding 516 kg Cl ha-1 yr-1 with application of NH4Cl,KCl,and KH2PO4 （Cl-）.Under each treatment,the applied N,P,and K nutrients were controlled at conventional rates of 150 kg N ha-1 yr-1,75 kg P2O5 ha-1 yr-1,225 kg K2O ha-1 yr-1,respectively.Under the S-containing fertilizer application,soil SO42--S content showed a first increasing then decreasing trend with years,and was significantly negatively correlated with annual rice yield.Average annual yield significantly declined in an order of Cl-,Cl-＋SO42-,and SO42-.Under the Cl-treatment,soil SO42--S content was maintained at about 26.5 mg kg-1,not showing deficiency.From 1990 to 2000,rice yield declined rapidly under the SO42- treatment,and was significantly lower than that under the Cltreatment.After then,there was no significant difference in yield among the treatments.Our results demonstrated that long-term application of S- containing fertilizer could result in excessive accumulation of SO42--S in the red paddy soils of south China,therefore producing a certain threat to rice growth.The Cl- containing fertilizer could be relatively safe.
基金financially supported by Australian Research Council Discovery Project(DP200100965)。
文摘Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO_(2)RR conditions. A synthetic approach is developed to electrochemically convert Bi^(O)Cl into Cl-containing subcarbonate(Bi_(2)O_(2)(CO_(3))_(x)Cl_(y)) under operando CO_(2)RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) via a cathodic potential-promoted anion-exchange process. The operando synthesizedBi_(2)O_(2)(CO_(3))_(x)Cl_(y) can tolerate-1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi_(2)O_(2)CO_(3),the formation of metallic Bio occurs at-0.6 V versus RHE. At-0.8 V versus RHE, Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) can readily attain a FEHCOO-of 97.9%,much higher than that of the pure Bi_(2)O_(2)CO_(3)(81.3%). DFT calculations indicate that differing from the pure Bi_(2)O_(2)CO_(3)-catalyzed CO_(2)RR, where formate is formed via a *OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of H COO-over Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) has proceeded via a *COOH intermediate step that only requires low energy input of 2.56 eV.
