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作 者 ：李贵桐;赵紫娟;黄元仿;李保国

期 刊 ：植物营养与肥料学报 2002年 8卷 2期 页码：162-167

关键词：土壤氮矿化；原状土柱田间培养法；秸秆还田；土壤微生物量氮；

Keywords:soil N mineralization, in situ incubation method, straw returning, soil microbial biomass N,

摘 要 ：利用原状土柱田间培养法 ,测定了冬小麦、夏玉米农田土壤氮 (N)素的年净矿化量 ;利用氯仿熏蒸浸提茚三酮反应氮法测定了土壤微生物量氮的数量 ;利用连续流动分析仪测定了土壤表层无机氮的含量。结果表明 ,在冬小麦秸秆覆盖、夏玉米秸秆翻埋的土壤中 ,第 1年土壤氮净矿化量为N 210kg/hm²,第 2年为 179kg/hm²,2年的净矿化量均基本与同期施氮量相当。在秸秆不还田的土壤中 ,第 1年土壤氮净矿化量为N 164kg/hm²,第 2年为248kg/hm²,年际变化较大。翻埋玉米秸秆导致小麦季土壤表层无机氮数量增加 ,引发土壤氮矿化的正激发效应 ;表层覆盖小麦秸秆对玉米季土壤表层无机氮的影响不明显。秸秆还田后 ,每个生育期开始时 ,土壤微生物量氮比不还田土壤的增加 72 %～ 2.34% ,每个生育期结束时增加 34%～ 72%。在实施秸秆还田的最初 2年内 ,土壤微生物量但氮处于动态调整阶段 ,尚未达到新的稳定状态

Abstract:The amount of soil nitrogen net mineralization in field cropped with winter wheat and summer maize was measured by in situ incubation method The soil microbial biomass nitrogen was measured by chloroform fumigation extraction and ninhydrin reactive nitrogen method The soil inorganic N was measured by continued flow analysis instrument In the soil covered with winter wheat straw in summer and incorporated with summer maize straw in autumn, the net N mineralization was 210kg/hm² in the first year, 179 kg/hm² in the second year The net mineralization was approximately equal to the amount of applied N In the non-straw returning soil the net mineralization was 164 and 248 kg/hm² in the first and second year, respectively Incorporating maize straw to the soil resulted in increase of inorganic N during wheat season and positive effect of soil N mineralization Surfacing wheat straw in summer gave no significant difference in soil inorganic N The soil microbial biomass N in straw returning soil was 72～234% greater than that in the non-straw returning at beginning of each season, and was 34～72% greater at ending of each season The soil microbial biomass N in straw returning soil alternate during the first 2 years and did not be stable at a new level

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