Journal article

Publication year: 2018

Pages: 47-55

Journal: Geoderma

Volume number: 317

DOI Link: https://doi.org/10.1016/j.geoderma.2017.12.021

Publisher: Elsevier

Abstract: 

Nitrite (NO2-) is an intermediate in a number of soil N transformations, and is a precursor for NO and N2O emissions. Due to the transient nature of NO2- it is often neglected in N cycling research. Thus, the full suite of production and consumption pathways of NO2- in terrestrial ecosystems is poorly understood. The primary objectives of this study were to clarify the production and consumption pathways of NO2- in the acidic forest soils and compare the NO2- dynamics between temperate and subtropical forest soils. A series of N-15 tracing studies were performed, where 15N was added as NH4+, NO3-, or NO2- to temperate and subtropical forest soils, and NO2- transformations were investigated in these acidic forest soils. The results showed that the average NO2- production rates ranged from 4.42 to 5.90 mg kg(-1)d(-1) and from 1.29 to 2.77 mg kg(-1)d(-1) in the temperate and subtropical forest soils, respectively, within the 1-6 h incubations. Oxidation of soil organic N was the dominant NO2- production pathway in the acidic forest soils, which was negatively related to soil pH (p < 0.01). The average consumption rates of NO2- varied during the incubation period from 12.46 to 14.10 mg kg(-1)d(-1) and from 5.84 to 6.74 mg kg(-1)d(-1) in the temperate and subtropical forest soils, respectively. The NO3- pool recovered 6-44% of added N-15-NO2- in the studied forest soils, which was positively related to soil pH (p < 0.05). The 32-36% of added N-15-NO2- was incorporated into insoluble soil organic N pool (SON) associated with soil organic C concentration. Nitrite incorporation into DON was also important for soil N retention in the subtropical strongly acidic forest soils (pH 4.7), however, in the temperate acidic forest soils, N-15 was not detected in the DON pool. Self-decomposition of NO2- to NO and NO2 was a main pathway under subtropical strongly acidic conditions. The NO2- turnover was most likely the key driving force for N transformations in the acidic forest soils. Further work regarding the dynamics of NO2- and their mechanisms in soils of the different terrestrial ecosystems is important to gain an improved understanding of the global N cycle.

Harvard Citation style: Yang, D., Dai, S., Zhang, J., Müller, C. and Cai, Z. (2018) Nitrite transformations under acidic conditions in temperate and subtropical forest ecosystems, Geoderma, 317, pp. 47-55. https://doi.org/10.1016/j.geoderma.2017.12.021

APA Citation style: Yang, D., Dai, S., Zhang, J., Müller, C., & Cai, Z. (2018). Nitrite transformations under acidic conditions in temperate and subtropical forest ecosystems. Geoderma. 317, 47-55. https://doi.org/10.1016/j.geoderma.2017.12.021