Journal article

Publication year: 2016

Pages: 2949-2959

Journal: Journal of Geophysical Research: Biogeosciences

Volume number: 121

Issue number: 12

ISSN: 2169-8953

eISSN: 2169-8961

Open access status: Bronze

DOI Link: https://doi.org/10.1002/2016JG003533

Publisher: American Geophysical Union

Abstract: 

Temperate grasslands in arid and semiarid regions cover about 40% of the total land area in China. So far, only a few studies have studied the N transformations in these important ecosystems. In the present study, soil gross N transformation rates in Inner Mongolia temperate grasslands in China were determined using a N-15 tracing experiment and combined with a literature synthesis to identify the soil N transformation characteristics and their controlling factors in a global perspective. Our results showed that the rates of gross N mineralization and immobilization NH4+ were significantly lower, while autotrophic nitrification rates were significantly higher in Chinese temperate grassland soils compared to other regions in the world. In particular, the primary mineral N consumption processes, i.e., immobilization of NO3- and NH4+, and dissimilatory nitrate reduction to ammonium, were on average much lower in temperate grassland soils in China, compared to other temperate grassland regions. The reduced heterotrophic activity and microbial growth associated with lower soil organic carbon and arid climate (e.g., mean annual precipitation) were identified as the main factors regulating soil N cycling in the studied regions in China. To restrict NO3- accumulation and associated high risks of N losses in these arid and semiarid ecosystems in China, it is important to develop the regimes of soil organic C and water management that promote the retention of N in these grassland ecosystems.

Harvard Citation style: Wang, J., Wang, L., Feng, X., Hu, H., Cai, Z., Müller, C., et al. (2016) Soil N transformations and its controlling factors in temperate grasslands in China: A study from 15N tracing experiment to literature synthesis, Journal of Geophysical Research: Biogeosciences, 121(12), pp. 2949-2959. https://doi.org/10.1002/2016JG003533

APA Citation style: Wang, J., Wang, L., Feng, X., Hu, H., Cai, Z., Müller, C., & Zhang, J. (2016). Soil N transformations and its controlling factors in temperate grasslands in China: A study from 15N tracing experiment to literature synthesis. Journal of Geophysical Research: Biogeosciences. 121(12), 2949-2959. https://doi.org/10.1002/2016JG003533