Nitrogen addition stimulated soil respiration more so than carbon addition in alpine meadows

Mei Huang; Xiaopeng Chen; A Allan Degen; Ruiying Guo; Tao Zhang; Binyu Luo; Haiyan Li; Jingxue Zhao; Zhanhuan Shang

doi:10.1016/j.envres.2023.116501

Nitrogen addition stimulated soil respiration more so than carbon addition in alpine meadows

Environ Res. 2023 Sep 15:233:116501. doi: 10.1016/j.envres.2023.116501. Epub 2023 Jun 24.

Authors

Mei Huang¹, Xiaopeng Chen², A Allan Degen³, Ruiying Guo¹, Tao Zhang¹, Binyu Luo¹, Haiyan Li⁴, Jingxue Zhao¹, Zhanhuan Shang⁵

Affiliations

¹ State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China.
² College of Grassland Science, Shanxi Agricultural University, Taigu, 030801, China.
³ Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer Sheva, 8410500, Israel.
⁴ Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, Jilin, 130024, China.
⁵ State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China. Electronic address: shangzhh@lzu.edu.cn.

PMID: 37356529
DOI: 10.1016/j.envres.2023.116501

Abstract

The soil carbon (C) and nitrogen (N) availability are important in the regulation of soil C cycling under climate change. Fertilizers alter soil C and N availability, which can affect C balance. However, the impact of fertilizers on C balance in grassland restoration has been equivocal and warrants more research. We determined the direct and indirect effects of the addition of three levels of C (sucrose) (0, 60, and 120 kg C ha^-1 yr^-1), three levels of N (urea) (0, 50, and 100 kg N ha^-1 yr^-1), and a combination of C plus N at each of the levels on soil respiration (Rs) dynamics and C balance in an alpine meadow in northern Tibet (4700 m above sea level). This study was undertaken during the middle of the growing season in 2011-2012. The addition of C and/or N stimulated CO₂ emission, which was 2-fold greater in 2011 (102-144 g C m^-2) than in 2012 (43-54 g C m^-2). The rate of Rs increased with the addition of N, but was not affected with the addition of C plus N. Microbial biomass C, dissolved organic C and inorganic N were the main drivers of Rs. We concluded that N addition stimulated Rs to a greater extent than C addition in the short term. The application of fertilizer in the restoration of degraded grassland should be re-considered.

Keywords: CO(2) emission; Carbon availability; Carbon balance; Fertilizer; Nitrogen availability; Northern Tibet.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carbon
Ecosystem
Fertilizers
Grassland*
Nitrogen* / analysis
Soil

Substances

Nitrogen
Carbon
Soil
Fertilizers