• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>European Journal of Soil Science >Nitrogen addition and mowing affect microbial nitrogen transformations in a C4 grassland in northern China
【24h】

Nitrogen addition and mowing affect microbial nitrogen transformations in a C4 grassland in northern China

机译：氮的添加和割草影响中国北方C4草原的微生物氮转化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Microbial nitrogen (N) transformations play a key role in regulating N cycling in grassland ecosystems. However, there is still little information on how management of semi-arid grassland such as mowing and/or N fertilizer application affects microbial activity and N transformations. In a field experiment in northern China, N was added at a rate of 10 g N m(-2) year(-1) as NH4NO3 to mown and unmown plots (4 x 4 m(2)) and in situ rates of net ammonification (R-amm), nitrification (R-nit) and mineralization (R-min) were followed at monthly intervals for the vegetation growth periods in the years 2006-2009. In addition, we also measured soil microbial biomass carbon (MBC) and nitrogen (MBN), microbial respiration (MR) and peak above-ground biomass in August of each measurement year. Driven by the pronounced inter-annual variability of rainfall, all the properties investigated varied markedly across years. Nevertheless, we were able to demonstrate that over the 4 years N addition significantly stimulated R-nit, R-min and MBN, on average, by 288, 149 and 11.6%, respectively. However, N addition decreased MBC significantly as well as the ratio of MBC:MBN by, on average, 10 and 23%, respectively, whereas an effect of N addition on MR could not be demonstrated. Mowing decreased MBN, MR and qCO(2) significantly by 9, 28 and 24%, respectively, but no effects were found on microbial net N transformation rates and MBC. N addition and mowing interactively affected R-amm and R-min, and MBN, MBC:MBN. In summary, our results indicate a positive effect of N addition but a negative effect of mowing on microbial N transformation in this C4 grassland in northern China.
机译：微生物氮（N）的转化在调节草地生态系统中的氮循环中起关键作用。但是，关于半干旱草原的管理（例如割草和/或施用氮肥）如何影响微生物活性和氮素转化的信息仍然很少。在中国北方的田间试验中，以10 g N m（-2）年（-1）的速率将N作为NH4NO3添加到已割和未割田（4 x 4 m（2））和原位网速中在2006-2009年的植被生长期间，每月进行氨化（R-amm），硝化（R-nit）和矿化（R-min）。此外，我们还在每个测量年的8月测量了土壤微生物生物量碳（MBC）和氮（MBN），微生物呼吸（MR）和地上生物量峰值。在明显的年际降水变化的驱动下，所调查的所有特性在多年中都有显着变化。然而，我们能够证明，在过去的4年中，氮的添加分别显着地分别使R-nit，R-min和MBN分别提高了288、149和11.6％。然而，氮的添加显着降低了MBC以及MBC：MBN的比例，平均分别降低了10％和23％，而无法证明氮的添加对MR的影响。割草分别将MBN，MR和qCO（2）分别降低了9％，28％和24％，但未发现对微生物净氮转化率和MBC的影响。 N的添加和修剪对R-amm和R-min以及MBN，MBC：MBN产生交互影响。总而言之，我们的研究结果表明，在中国北方这个C4草地上，增施氮肥对微生物氮的转化有负面影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号