生态环境学报 ›› 2022, Vol. 31 ›› Issue (12): 2302-2309.DOI: 10.16258/j.cnki.1674-5906.2022.12.004

• 研究论文 • 上一篇    下一篇

氮磷添加对高寒草地土壤养分和相关酶活性的影响

盛基峰1,2,3(), 李垚3,4, 于美佳3,4, 韩艳英1,2,3,4, 叶彦辉1,2,3,4,*()   

  1. 1.西藏农牧学院高原生态研究所,西藏 林芝 860000
    2.西藏高原森林生态教育部重点实验室;西藏 林芝 860000
    3.西藏高寒植被生态安全重点实验室,西藏 林芝 860000
    4.西藏农牧学院资源与环境学院,西藏 林芝 860000
  • 收稿日期:2022-09-22 出版日期:2022-12-18 发布日期:2023-02-15
  • 通讯作者: *叶彦辉,E-mail: yeyanhui3554@126.com
  • 作者简介:盛基峰(1998年生),男,硕士研究生,主要从事高寒草地氮沉降研究。E-mail: 2459993896@qq.com
  • 基金资助:
    西藏高寒植被生态安全重点实验室开放基金项目(STAQ-2021Y-4);国家自然科学基金项目(31860141);国家自然科学基金项目(31360119);中央引导地方项目(XZ202101YD0016C);西藏农牧学院第四批柔性人才项目(604419044);西藏高原森林生态教育部重点实验室资助

Effects of Nitrogen and Phosphorus An Addition on Soil Nutrients and Activity of Related Enzymes in Alpine Grassland

SHENG Jifeng1,2,3(), LI Yao3,4, YU MeiJia3,4, HAN Yanying1,2,3,4, YE Yanhui1,2,3,4,*()   

  1. 1. Research Institute of Tibet Plateau Ecology, Tibet Agricultural and Animal Husbandry College, Nyingchi 860000, P. R. China
    2. Key Laboratory of Forest Ecology of Tibet Plateau, Ministry of Education, Nyingchi 860000, P. R. China
    3. Key Laboratory of Alpine Vegetation Ecological Security, Nyingchi 860000, P. R. China
    4. Faculty of Forest Resources and Environmental Science, Tibet Agricultural and Animal Husbandry College, Nyingchi 860000, P. R. China
  • Received:2022-09-22 Online:2022-12-18 Published:2023-02-15

摘要:

土壤是陆地生态系统的重要组分,其养分条件决定了植物生长状况及生产力的大小。氮和磷是植物生长的必需营养元素和主要限制因子,氮磷增加会改变土壤性质,影响土壤中的氮、磷含量,从而对土壤地上植物生长造成影响。为评估氮磷添加对草地土壤养分的影响及为高寒草地如何应对氮磷沉降提供科学依据,在藏东南色季拉山高寒草地开展氮磷添加试验,共设置对照(CK,不添加)、氮添加(N,15 kg?hm?2?a?1)、磷添加(P,75 kg?hm?2?a?1)、氮磷混合添加(NP:15 kg?hm?2?a?1 N;75 kg?hm?2?a?1 P)等4个施肥处理,施肥1年后采集土壤样品在实验室进行相关指标测定。试验结果表明,N、P和NP处理均显著促进高寒草地土壤有机碳、全氮、铵态氮、硝态氮和有效磷含量(P<0.05)。其中,NP添加对有机碳影响最大,增加了50.86%;N添加下土壤全氮、铵态氮、硝态氮和有效磷含量达到最大增幅,分别增加了59.14%、47.58%、333.85%和59.68%;NP添加下显著促进全磷含量(P<0.05),增加了19.41%,表明NP添加对土壤养分含量有积极影响,且影响较大。不同处理均显著促进蔗糖酶、葡萄糖苷酶和脲酶活性(P<0.05),N和NP添加对蔗糖酶和葡萄糖苷酶影响较大,增幅在53.08%—92.63%之间,P添加下脲酶活性增幅最大,达到140.73%。相关性分析表明,土壤有效养分与土壤酶活性之间显著相关,pH与土壤养分和酶活性呈显著相关(P<0.05)。结果表明,NP添加对土壤碳氮相关养分和酶活性影响较大,均呈现显著促进作用,且养分和酶活性之间呈现交互影响。NP添加通过提高土壤酶活性,加快土壤中大分子有机物分解,从而使土壤养分含量增加。N添加对土壤氮相关养分影响较大,表明施氮可缓解青藏高原高寒草地氮限制。

关键词: 氮磷肥, 碳氮循环酶, 土壤养分, 高寒草地, 色季拉山

Abstract:

Soil is an important component of terrestrial ecosystem, and its nutrient conditions determine plant growth and productivity. Nitrogen and phosphorus are essential nutrients and main limiting factors for plant growth. The increase of nitrogen and phosphorus will change soil properties and affect the content of nitrogen and phosphorus in soil, and thus affect the growth of above-ground plants in soil. In order to evaluate the effects of nitrogen and phosphorus addition on grassland soil nutrients and provide a scientific basis for alpine grassland to cope with nitrogen and phosphorus deposition, nitrogen and phosphorus addition experiments were carried out in alpine grassland of Sejila Mountain, southeast Tibet. The experiments included four fertilization treatments: control (CK, no addition), nitrogen addition (N, 15 kg?hm?2?a?1), phosphorus addition (P, 75 kg?hm?2?a?1), and nitrogen and phosphorus (NP: 15 kg?hm?2?a?1 N; 75 kg?hm?2?a?1 P). Soil samples were collected one year after the fertilization for measurement of relevant indexes in the laboratory. The results showed that: N, P and NP treatments significantly promoted the contents of soil organic carbon, total nitrogen, ammonium nitrogen, nitrate nitrogen and available phosphorus in alpine grassland (P<0.05). NP addition had the greatest effect on organic carbon, which increased by 50.86%. The contents of soil total nitrogen, ammonium nitrogen, nitrate nitrogen and available phosphorus increased most under N addition, which were 59.14%, 47.58%, 333.85% and 59.68%, respectively. NP addition significantly promoted the total phosphorus content (P<0.05), which increased by 19.41%, indicating that NP addition had a positive effect on soil nutrient content, and the effect was relatively large. Different treatments significantly promoted the activities of sucrase, glucosidase and urease (P<0.05). N and NP supplementation had a significant effect on the activities of sucrase and glucosidase, with an increase of 53.08% to 92.63%, and the urease activity increased most under P supplementation, reaching 140.73%. Correlation analysis showed that soil available nutrients were significantly correlated with soil enzyme activities, and pH was significantly correlated with soil nutrient and enzyme activities (P<0.05). The results showed that NP addition had a significant effect on soil C and N related nutrients and enzyme activities, and both of which showed significant promotion effect, and there was an interactive effect between nutrients and enzyme activities. NP addition accelerated the decomposition of macromolecular organic matter in soil by increasing soil enzyme activity and increasing soil nutrient content. N addition had a significant effect on soil nitrogen related nutrients, indicating that N application could alleviate nitrogen limitation in alpine grassland of Qinghai-Tibet Plateau.

Key words: nitrogen and phosphorus fertilizer, carbon and nitrogen cycle enzymes, soil nutrients, alpine grassland, Sejila mountain

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