Open Access

ARTICLE

How Physical Disturbance and Nitrogen Addition Affect the Soil Carbon Decomposition?

Muhammad Junaid Nazir^1,2, Xiuwei Zhang^1,*, Daolin Du², Feihai Yu¹
1 Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, 318000, China
2 College of the Environment & Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
* Corresponding Author: Xiuwei Zhang. Email:
(This article belongs to this Special Issue: The Effect of Soil Quality Degradation on the Plant Growth, Quality and Food Safety in Subtropical Agroforestry Ecosystems)

Phyton-International Journal of Experimental Botany 2022, 91(9), 2087-2097. https://doi.org/10.32604/phyton.2022.021412

Received 13 January 2022; Accepted 04 March 2022; Issue published 13 May 2022

Abstract

The decomposition of soil organic carbon (SOC) plays a critical role in regulating atmospheric CO₂ concentrations and climate dynamics. However, the mechanisms and factors controlling SOC decomposition are still not fully understood. Here, we conducted a 60 days incubation experiment to test the effects of physical disturbance and nitrogen (N) addition on SOC decomposition. N addition increased the concentration of NO₃^- by 51% in the soil, but had little effect on the concentration of NH₄⁺. N addition inhibited SOC decomposition, but such an effect differed between disturbed and undisturbed soils. In disturbed and undisturbed soils, application of N decreased SOC decomposition by 37% and 15%, respectively. One possible explanation is that extra N input suppressed microbial N mining and/or increased the stability of soil organic matter by promoting the formation of soil aggregates and incorporating part of the inorganic N into organic matter, and consequently decreased microbial mineralization of soil organic matter. Physical disturbance intensified the inhibition of N on SOC decomposition, likely because physical disturbance allowed the added N to be better exposed to soil microbes and consequently increased the availability of added N. We conclude that physical disturbance and N play important roles in modulating the stability of SOC.

---

Keywords

Soil organic matter; physical disturbance; microbial N mining; microbial biomass carbon; N availability

---