TY - EJOU AU - Nazir, Muhammad Junaid AU - Zhang, Xiuwei AU - Du, Daolin AU - Yu, Feihai TI - How Physical Disturbance and Nitrogen Addition Affect the Soil Carbon Decomposition? T2 - Phyton-International Journal of Experimental Botany PY - 2022 VL - 91 IS - 9 SN - 1851-5657 AB - 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. KW - Soil organic matter; physical disturbance; microbial N mining; microbial biomass carbon; N availability DO - 10.32604/phyton.2022.021412