| Mitrification-Denitrification Loss of Added Nitrogen in Flooded RiceRhizosphere |
| |
| 作者姓名： | LI XIN-HUI ZHU ZHAO-LIANG CAI GUI-XIN ZHOU KE-YU CAO YA-CHENG |
| |
| 作者单位： | [1]InstituteofSoilScience,AcademiaSinica,P.O.Box821,Nanjing,China [2]InstituteofSoilScience,AcademiaSinica, |
| |
| 摘 要： | Nitrification-denitrification losses of 15N-labelled nitrate and ammonium applied to the rhizos phere and nonrhizosphere of flooded rice were evaluated in 2 greenhouse rhizobox experiments.The loss of added N via denitrification was estimated directly by measuring the total fluxes of (N2O N2)12N,It was found that 67% and 51%-56% of 15N-nitrate added to rice rhizosphere were lost as (N2O N2)-15N in the 2 experiments,respectively,which were comparable to that added to norhizosphere soil(70%and 47%,respectively),implying that the denitrifying activity in rice rhizosphere was as high as that in nonrhizosphere soil.However,only trace amounts (0-0\3% of added N)were recovered as (N2O N2)-15N when 15N-ammonium was applied to either rhizosphere or nonrhizosphere,which seems to indicate that the nitrifying activity in the either rhizosphere of nonrhizosphere soils was quite low.The apparent denitrification calculated from 15N balance studies was 10%-47% higher than the total flux of (N2O N2)-15N.Reasons for the large differences can not be explained satisfactorily.Though the denitrifying activity in rhizosphere was high and comparable to that in nonrhizosphere soil.presumably due to the low nitrifying activity and /or the strong competition of N uptake against denitrification.the nitrification-denitrification taking place in rhizosphere could not be an important mechanism of loss of ammonium N in flooded rice-soil system.
|
| 关 键 词： | 淹水水稻根系 施氮 硝化－反硝化作用 肥料氮损失 15氮平衡 |
Mitrification-Denitrification Loss of Added Nitrogen in Flooded RiceRhizosphere |
| |
| LI XIN-HUI,ZHU ZHAO-LIANG,CAI GUI-XIN,ZHOU KE-YU,CAO YA-CHENG.Mitrification-Denitrification Loss of Added Nitrogen in Flooded RiceRhizosphere[J].Pedosphere,1994,4(2):145-152. |
| |
| Authors: | LI XIN-HUI ZHU ZHAO-LIANG CAI GUI-XIN ZHOU KE-YU and CAO YA-CHENG |
| |
| Institution: | [1]InstituteofSoilScience,AcademiaSinica,P.O.Box821,Nanjing,China [2]InstituteofSoilScience,AcademiaSinica, |
| |
| Abstract: | Nitrification-denitrification losses of 15N-labelled nitrate and ammonium applied to the rhizos phere and nonrhizosphere of flooded rice were evaluated in 2 greenhouse rhizobox experiments.The loss of added N via denitrification was estimated directly by measuring the total fluxes of (N2O N2)12N,It was found that 67% and 51%-56% of 15N-nitrate added to rice rhizosphere were lost as (N2O N2)-15N in the 2 experiments,respectively,which were comparable to that added to norhizosphere soil(70%and 47%,respectively),implying that the denitrifying activity in rice rhizosphere was as high as that in nonrhizosphere soil.However,only trace amounts (0-0\3% of added N)were recovered as (N2O N2)-15N when 15N-ammonium was applied to either rhizosphere or nonrhizosphere,which seems to indicate that the nitrifying activity in the either rhizosphere of nonrhizosphere soils was quite low.The apparent denitrification calculated from 15N balance studies was 10%-47% higher than the total flux of (N2O N2)-15N.Reasons for the large differences can not be explained satisfactorily.Though the denitrifying activity in rhizosphere was high and comparable to that in nonrhizosphere soil.presumably due to the low nitrifying activity and /or the strong competition of N uptake against denitrification.the nitrification-denitrification taking place in rhizosphere could not be an important mechanism of loss of ammonium N in flooded rice-soil system. |
| |
| Keywords: | |
| 本文献已被 维普 等数据库收录！ |
| 点击此处可从《土壤圈》浏览原始摘要信息 |
| 点击此处可从《土壤圈》下载免费的PDF全文 |
|
