生态环境
生態環境
생태배경
ECOLOGY AND ENVIRONMENT
2008年
1期
368-376
,共9页
乌尼木仁%樗木直也%陈能场%稲永醇二
烏尼木仁%樗木直也%陳能場%稲永醇二
오니목인%저목직야%진능장%도영순이
15N%有机化%无机化%氮的行为%根箱%根际%水稻
15N%有機化%無機化%氮的行為%根箱%根際%水稻
15N%유궤화%무궤화%담적행위%근상%근제%수도
15N%Immobilization%Mineralization%N Behavior%Rice plant%Rhizobox%Rhizosphere
为研究水田土壤中氮的行为,施给15NH4+或15NO3-标记的硝胺(NH415NO3或15NH4NO3)的沙壤土(Shirasu soil)添充在根箱里,对Japonica水稻(品种Hinohikari)进行温室栽培6周.收割后,水稻植株分地上部和根部,对各自的全氮,15N atom％进行测定.根箱各区域的土壤按着鲜土形态进行采取后,对此全氮,NO3-N,水溶性NH4-N,KCl抽出NH4-N和其各自的15N atom％进行测定.研究结果表明,土壤全氮含量与栽培前相比,在非根际明显降低,但在根际比非根际要高,保持了与栽培前相同的水平.土壤NO3-N浓度从非根际到根际递增,但与其栽培前相比显著地降低,在整个根箱里,施给NO3-N的79％为因脱氮而损失.土壤中NO3-N的大部分来自于土壤氮化合物,来自施肥的比例却较低,尤其是在根际.反而,施给NO3-N的残存率约仅为16％左右,但其中有机态氮所占的比率在非根际里55％～86％,在根际却达到了93％.土壤水溶性NH4-N和KCl抽出NH4-N浓度靠近根际逐渐降低,而且在非根际两者匀由1∶10的比例存在,但在根际里水溶性NH4-N没被检索到.在非根际里,土壤KCl抽出NH4-N的35％～66％为来自施肥,但其比例在根际里却降到15％左右.在土壤中残存的来自施给NH4-N的氮化合物之中,有机态氮所占的比例在非根际里约为11％～65％,但在根际却达到了92％.以上结果表明,在水稻根际,氮的无机化和有机化的活性比非根际显著.
為研究水田土壤中氮的行為,施給15NH4+或15NO3-標記的硝胺(NH415NO3或15NH4NO3)的沙壤土(Shirasu soil)添充在根箱裏,對Japonica水稻(品種Hinohikari)進行溫室栽培6週.收割後,水稻植株分地上部和根部,對各自的全氮,15N atom％進行測定.根箱各區域的土壤按著鮮土形態進行採取後,對此全氮,NO3-N,水溶性NH4-N,KCl抽齣NH4-N和其各自的15N atom％進行測定.研究結果錶明,土壤全氮含量與栽培前相比,在非根際明顯降低,但在根際比非根際要高,保持瞭與栽培前相同的水平.土壤NO3-N濃度從非根際到根際遞增,但與其栽培前相比顯著地降低,在整箇根箱裏,施給NO3-N的79％為因脫氮而損失.土壤中NO3-N的大部分來自于土壤氮化閤物,來自施肥的比例卻較低,尤其是在根際.反而,施給NO3-N的殘存率約僅為16％左右,但其中有機態氮所佔的比率在非根際裏55％～86％,在根際卻達到瞭93％.土壤水溶性NH4-N和KCl抽齣NH4-N濃度靠近根際逐漸降低,而且在非根際兩者勻由1∶10的比例存在,但在根際裏水溶性NH4-N沒被檢索到.在非根際裏,土壤KCl抽齣NH4-N的35％～66％為來自施肥,但其比例在根際裏卻降到15％左右.在土壤中殘存的來自施給NH4-N的氮化閤物之中,有機態氮所佔的比例在非根際裏約為11％～65％,但在根際卻達到瞭92％.以上結果錶明,在水稻根際,氮的無機化和有機化的活性比非根際顯著.
위연구수전토양중담적행위,시급15NH4+혹15NO3-표기적초알(NH415NO3혹15NH4NO3)적사양토(Shirasu soil)첨충재근상리,대Japonica수도(품충Hinohikari)진행온실재배6주.수할후,수도식주분지상부화근부,대각자적전담,15N atom％진행측정.근상각구역적토양안착선토형태진행채취후,대차전담,NO3-N,수용성NH4-N,KCl추출NH4-N화기각자적15N atom％진행측정.연구결과표명,토양전담함량여재배전상비,재비근제명현강저,단재근제비비근제요고,보지료여재배전상동적수평.토양NO3-N농도종비근제도근제체증,단여기재배전상비현저지강저,재정개근상리,시급NO3-N적79％위인탈담이손실.토양중NO3-N적대부분래자우토양담화합물,래자시비적비례각교저,우기시재근제.반이,시급NO3-N적잔존솔약부위16％좌우,단기중유궤태담소점적비솔재비근제리55％～86％,재근제각체도료93％.토양수용성NH4-N화KCl추출NH4-N농도고근근제축점강저,이차재비근제량자균유1∶10적비례존재,단재근제리수용성NH4-N몰피검색도.재비근제리,토양KCl추출NH4-N적35％～66％위래자시비,단기비례재근제리각강도15％좌우.재토양중잔존적래자시급NH4-N적담화합물지중,유궤태담소점적비례재비근제리약위11％～65％,단재근제각체도료92％.이상결과표명,재수도근제,담적무궤화화유궤화적활성비비근제현저.
Behavior of N in the rhizosphere of rice (Oryza sativa L.) plant was investigated using a rhizobox system filled with a shirasu soil applied with NH415NO3 or 15NH4NO3. The rhizobox consisted of one 2-mm width center compartment(CC), five 1-mm width compartments, and one bulk compartment(BC) on both sides of CC．Rice was sowed and grown in CC. After 6th weeks after clutivation,the soil from each compartment were collected and analyzed for contents and 15N excess％ of the soil total-N,water-soluble NO3-N,NH4-N and KCl-extractable NH4-N. The obtained results were summarized as follows: 1) The total-N content of soil decreased in all the compartments except CC compared with that before cultivation,but that of CC did not change. 2) The water-soluble NO3-N content of soil decreased remarkably in all the compartments compared with that before cultivation,and about 79% of applied NO3-N was lost from soil due to denitrification. The NO3-N content of soil slightly increased from BC toward CC. The most of NO3-N were derived from the soil N especially in the CC. 3) The contents of water-soluble NH4-N and KCl-extractable NH4-N decreased from BC toward CC and the ratio of water-soluble NH4-N to KCl-extractable NH4-N are 1:10 in all the compartments except CC which water-soluble NH4-N was not detected. 4) Mineralization of soil-N and immobilizaition of fertilizer-N were more actively at CC than in the other compartments.
