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Effects of exogenous organic/inorganic nitrogen addition on carbon pool distribution and transformation in grassland soil

Effects of exogenous organic/inorganic nitrogen addition on carbon pool distribution and transformation in grassland soil

Authors :
Menghan Wang
Fucui Li
Lili Dong
Xiang Wang
Liebao Han
Jørgen E. Olesen
Source :
Wang, M, Li, F, Dong, L, Wang, X, Han, L & Olesen, J E 2023, ' Effects of exogenous organic/inorganic nitrogen addition on carbon pool distribution and transformation in grassland soil ', Science of the total Environment, vol. 858, no. Part 3, 159919 . https://doi.org/10.1016/j.scitotenv.2022.159919
Publication Year :
2023

Abstract

Aims: Increases in nitrogen (N) deposition may significantly affect the organic carbon (OC) cycle in soil. The inconsistent findings of the influence of added N on soil OC pools highlight the need of quantifying responses of the OC pool distribution to N addition. Moreover, the influence of N addition with a mixture of organic and inorganic N on OC pool distribution and stabilization in grassland soil remains unclear. Methods: We carried out a five-year field experiment with adding N to examine the effects of different types of N addition on soil OC pool distribution and transformation in a meadow steppe in Inner Mongolia. We applied N in the ratios of inorganic N (IN) and organic N (ON) at 10:0 (N1), 7:3 (N2), 5:5 (N3), 3:7 (N4), 0:10 (N5), and 0:0 (CK), respectively. We measured OC content in bulk soil, particulate organic matter (POM), and mineral-associated organic matter (MAOM) fractions. Additionally, a short-term soil incubation was conducted to assess potential OC mineralization. Results: Our study showed no significant effect on soil organic carbon content of different ratios of IN/ON addition. N addition reduced microbial biomass C/N ratio, the fraction of mineral-associated organic matter, cumulative CO2 emission, and microbial metabolic quotient. Compared with ON addition alone, IN addition alone showed a stronger effect on the C in different soil fractions and soil OC mineralization. The particulate organic matter (POM) fraction was more sensitive to N addition than the mineral-associated organic matter (MAOM) fraction. Conclusions: Our results suggest that the contribution of N in organic and inorganic forms affecting OC pool distribution with different turnover rates should be considered when assessing the effects of N addition types on soil OC processes in grassland.

Details

Language :
English
Database :
OpenAIRE
Journal :
Wang, M, Li, F, Dong, L, Wang, X, Han, L & Olesen, J E 2023, ' Effects of exogenous organic/inorganic nitrogen addition on carbon pool distribution and transformation in grassland soil ', Science of the total Environment, vol. 858, no. Part 3, 159919 . https://doi.org/10.1016/j.scitotenv.2022.159919
Accession number :
edsair.doi.dedup.....bb377ad6e1cd9a457a84cf49c854a0fb
Full Text :
https://doi.org/10.1016/j.scitotenv.2022.159919