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作 者 ：孙建,刘苗,李立军*,刘景辉,张星杰

期 刊 ：生态学报 2009年 29卷 10期 页码：5508~5515

关键词：免耕；留茬；土壤微生物量C；土壤微生物量N；土壤酶活性；

Keywords:non\|tillage, stubble, microbial biomass C, microbial biomass N, soil enzyme activity,

摘 要 ：2005~2008年在内蒙古呼和浩特市清水河县进行定位试验，设免耕留低茬（NL）、免耕留高茬覆盖（NHS）和传统耕翻（T）3种耕作处理方式。结果表明：（1）免耕留高茬覆盖及免耕留低茬长期实施，能显著提高表层土壤有机质、全氮、全钾、碱解氮、速效磷和速效钾含量，且免耕留高茬覆盖处理比传统耕翻分别提高了11％、41％、22％、15％、29％、27％、13％；在测定各个时期内，土壤各营养指标含量整体趋势为NHS＞NL＞T。（2）免耕留高茬覆盖及免耕留低茬耕作方式有利于提高土壤微生物量C、N含量，在各测定时期均以免耕留高茬覆盖处理的土壤微生物量C、N含量最高，传统耕翻最低。与传统耕翻相比，免耕留高茬覆盖处理土壤微生物量C、N含量分别平均提高了69％、43％；测定各个时期，不同处理土壤生物量C、N含量均以7月份含量最高、5月份次之、10月份最低。（3）免耕留高茬覆盖及免耕留低茬处理土壤碱性磷酸酶、蔗糖酶、过氧化氢酶活性和脲酶活性高于传统耕翻，整个测定期内免耕留高茬覆盖处理4种酶平均活性，分别较传统耕翻增加了57%、82%、93%和25%；春季土壤酶活性开始增强，在7月份蔗糖酶、过氧化氢酶和脲酶活性达到最大值，而碱性磷酸酶的峰值出现在6月份。土壤微生物量C、N及土壤酶活性是评价土壤质量的重要因子。

Abstract:Soil microbial biomass and enzyme activities can be used as the most sensitive indicators of soil quality for assessing the sustainability of agricultural ecosystems. The objective of this study was to determine the influence of three tillage practices, such as no tillage low stubble (NL), No tillage high stubble with residues (NHS) and conventional tillage (T) practices, on chemical, biological soil quality indicators in a degraded maize slope field under dry conditions. Samples were taken at soil depth of 0-20cm layer in the Qing Shuihe County of Inner Mongolia after a period of 4 years. The chloroform fumigation extraction method and traditional methods were used to measure microbial carbon, nitrogen, enzyme activities and chemical properties in soils. Treatment effects on measured variables were tested by analysis of variance and comparisons among treatment means were made using a Duncan Multiple Range test at P<0.05 level. Statistical procedures and figures were carried out with the software package SPSS16.0 and Sigmaplot 10.0. The results showed that: (1) No tillage high stubble with residues and no tillage low stubble practices could raise soil organic matter (SOM), total nitrogen (TN), total phosphorus (TPP), total potassium (TPK), available nitrogen (AN),available phosphorus (APP), and available potassium (APK) remarkably. The NHS increased SOM by 11%, TN by 41%, TPP 22%, TPK15%, AN 29%, APP 27% and APK 27%compared to T. (2) Soil microbial biomass carbon was higher in soils under NHS (increased by 69%) and NL (increased by 22%), moreover, Soil microbial biomass nitrogen was greater in soils under NHS (increased by 43%) and NL (increased by 14%) compared to T for 0-20 cm depth, respectively. Soil microbial biomass carbon and nitrogen was up to peak in July and in excess in May and October. (3) We measured alkaline phosphatase, invertase, hydrogen peroxidase and urease, enzyme activities in NHS are enhanced by 57%, 82%, 92% and 25% respectively, over T. The, phosphatase reached peak in June, while others′ peak in July.

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