| 氮素添加对青藏高原高寒草甸植被和土壤氮素供应能力的影响 |
| Alternative Title | Effects of nitrogen adding on plant community and soil nitrogen supply ability of alpine meadow in Qinghai-Tibet Plateau
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| 郭雅婧 |
| Thesis Advisor | 沈禹颖
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| 2015-11-21
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| Degree Grantor | 兰州大学
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| Place of Conferral | 兰州
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| Degree Name | 硕士
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| Keyword | 高寒草甸
氮素添加
群落
有机氮
氮素矿化潜力
氮素矿化速率
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| Abstract | 以甘肃省甘南藏族自治州夏河县高寒草甸为对象，连续2年的野外定位研究，测定了在围封和放牧条件下，氮肥添加对草地植物群落及土壤氮含量的影响，结合室内长期间歇淋洗好氧培养和温室盆栽生物测试分析了高寒草甸的氮素有效性特征。得到以下主要结果：
（1）氮素添加当年草地生物量增加；毒草生物量所占比例较对照降低。氮素添加显著增加了施氮当年土壤矿质氮含量和施氮次年围封样地土壤硝态氮含量。
（2）实验室长期间歇淋洗好氧培养下，土壤有机氮铵化速率、硝化速率随着有机氮（牛粪）添加浓度的增加先升高后降低。高寒草甸土壤氮素矿化以铵态氮为主体，放牧可以促进土壤硝态氮的矿化。铵态氮和硝态氮矿化量此消彼长。
（3）3次燕麦的生物量、叶面积指数和根系总长度依次大幅降低。温室条件下，有机氮添加降低了燕麦全株的吸氮量，增加了燕麦种植后土壤残余氮，增加了土壤有机氮矿化量。有机肥氮素矿化率随着施肥量的增加而降低。 |
| Other Abstract | To find out the characteristics of soil nitrogen mineralization ability, the response of fenced and grazed grassland to nitrogen addition was tested in an alpine meadow in Xiahe county of Gansu province in combination with the long-term aerobic intermittent leaching method and green house pot-test. The main results are as follows:
（1）Nitrogen addition improved grassland biomass. In the second year, biomass of the gramineae grass began to decline while poisonous weeds and forbs biomass increased in fenced grassland. Nitrogen addition can significantly increase soil mineral nitrogen in the current year and nitrate content under fenced plots in following year.
（2）After the long-term leaching aerobic cultivation, the rate of soil nitrogen ammonium and nitrification showed a single peak trend with the increase of nitrogen addittion. Ammonium nitrogen dominates mineralized nitrogen in alpine soil. Grazing can increase soi nitrate mineralization. Ammonium and nitrate mineralization were inter-restricted. Temperature determines soil nitrogen mineralization potential of alpine meadow, but has little effect on mineralization rate.
（3）Under greenhouse condition, organic nitrogen addtion had little positive effect on the biomass accumulation of oat planted in alpine meadow soils. Under greenhouse condition，organic fertilizer nitrogen mineralization rate was significantly negatively related to the amount of fertilizer. |
| URL | 查看原文
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| Language | 中文
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| Document Type | 学位论文
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| Identifier | https://ir.lzu.edu.cn/handle/262010/198796
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| Collection | 草地农业科技学院
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Recommended Citation
GB/T 7714 |
郭雅婧. 氮素添加对青藏高原高寒草甸植被和土壤氮素供应能力的影响[D]. 兰州. 兰州大学,2015.
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