Abstract
Soil acidification is a major global issue of sustainable development for ecosystems. The increasing soil acidity induced by excessive nitrogen (N) fertilization in farmlands has profoundly impacted the soil carbon dynamics. However, the way in which changes in soil pH regulating the soil carbon dynamics in a deep soil profile is still not well elucidated. In this study, through a 12-year field N fertilization experiment with three N fertilizer treatments (0, 120, and 240 kg N/(hm2•a)) in a dryland agroecosystem of China, we explored the soil pH changes over a soil profile up to a depth of 200 cm and determined the responses of soil organic carbon (SOC) and soil inorganic carbon (SIC) to the changed soil pH. Using a generalized additive model, we identified the soil depth intervals with the most powerful statistical relationships between changes in soil pH and soil carbon dynamics. Hierarchical responses of SOC and SIC dynamics to soil acidification were found. The results indicate that the changes in soil pH explained the SOC dynamics well by using a non-linear relationship at the soil depth of 0–80 cm (P=0.006), whereas the changes in soil pH were significantly linearly correlated with SIC dynamics at the 100–180 cm soil depth (P=0.015). After a long-term N fertilization in the experimental field, the soil pH value decreased in all three N fertilizer treatments. Furthermore, the declines in soil pH in the deep soil layer (100–200 cm) were significantly greater (P=0.035) than those in the upper soil layer (0–80 cm). These results indicate that soil acidification in the upper soil layer can transfer excess protons to the deep soil layer, and subsequently, the structural heterogeneous responses of SOC and SIC to soil acidification were identified because of different buffer capacities for the SOC and SIC. To better estimate the effects of soil acidification on soil carbon dynamics, we suggest that future investigations for soil acidification should be extended to a deeper soil depth, e.g., 200 cm.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Adams T M, Adams S N. 1983. The effects of liming and Soil-pH on carbon and nitrogen contained in the soil biomass. Journal of Agricultural Science, 101(3): 553–558.
Ahmad W, Singh B, Dijkstra F A, et al. 2013. Inorganic and organic carbon dynamics in a limed acid soil are mediated by plants. Soil Biology and Biochemistry, 57: 549–555.
Ahmad W, Singh B, Dalal R C, et al. 2015. Carbon dynamics from carbonate dissolution in Australian agricultural soils. Soil Research, 53(2): 144–153.
Andersson S, Nilsson S I, Saetre P. 2000. Leaching of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in mor humus as affected by temperature and pH. Soil Biology and Biochemistry, 32(1): 1–10.
Bolan N S, Adriano D C, Curtin D. 2003. Soil acidification and liming interactions with nutrient and heavy metal transformation and bioavailability. Advances in Agronomy, 78: 215–272.
Campbell C A, Zentner R P. 1984. Effect of fertilizer on soil pH after 17 years of continuous cropping in southwestern saskatchewan. Canadian Journal of Soil Science, 64(4): 705–710.
Canadell J, Jackson R B, Ehleringer J R, et al. 1996. Maximum rooting depth of vegetation types at the global scale. Oecologia, 108(4): 583–595.
Curtin D, Campbell C A, Jalil A. 1998. Effects of acidity on mineralization: pH-dependence of organic matter mineralization in weakly acidic soils. Soil Biology and Biochemistry, 30(1): 57–64.
Díaz-Hernández J L. 2010. Is soil carbon storage underestimated? Chemosphere, 80(3): 346–349.
Dong Y J, Cai M, Zhou J B. 2013. The stocks and characteristics of organic and inorganic carbon in Lou soil in Yangling, Shaanxi. Journal of Northwest A&F University, 41(2): 152–158. (in Chinese)
Guo J H, Liu X J, Zhang Y, et al. 2010. Significant acidification in major Chinese croplands. Science, 327(5968): 1008–1010.
Iwald J. 2016. Acidification of Swedish forest soils. Licentiate Thesis. Uppsala: Swedish University of Agricultural Sciences.
Jackson R B, Canadell J, Ehleringer J R, et al. 1996. A global analysis of root distributions for terrestrial biomes. Oecologia, 108(3): 389–411.
Karlsson T. 2013. Soil carbon, pH and yield development in a long-term humus balance trial. MSc Thesis. Uppsala: Swedish University of Agricultural Sciences.
Kemmitt S J, Wright D, Goulding K W T, et al. 2006. pH regulation of carbon and nitrogen dynamics in two agricultural soils. Soil Biology and Biochemistry, 38(5): 898–911.
Khan S A, Mulvaney R L, Ellsworth T R, et al. 2007. The myth of nitrogen fertilization for soil carbon sequestration. Journal of Environmental Quality, 36(6): 1821–1832.
Lal R. 2004. Carbon sequestration in dryland ecosystems. Environmental Management, 33(4): 528–544.
Li S Y, Li H X, Yang C L, et al. 2016. Rates of soil acidification in tea plantations and possible causes. Agriculture, Ecosystems & Environment, 233: 60–66.
Li Z P, Han F X, Su Y, et al. 2007. Assessment of soil organic and carbonate carbon storage in China. Geoderma, 138(1–2): 119–126.
Meng H Q, Xu M G, Lu J L, et al. 2013. Soil pH dynamics and nitrogen transformations under long-term chemical fertilization in four typical Chinese croplands. Journal of Integrative Agriculture, 12(11): 2092–2102.
R Development Core Team. 2016. R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.
Ramnarine R, Wagner-Riddle C, Dunfield K E, et al. 2012. Contributions of carbonates to soil CO2 emissions. Canadian Journal of Soil Science, 92(4): 599–607.
Rengel Z. 2003. Handbook of Soil Acidity. New York: Marcel Dekker, 1–496.
Richter D D, Markewitz D. 1995. How deep is soil? BioScience, 45(9): 600–609.
Richter D D, Bacon A R, Brecheisen Z, et al. 2015. Soil in the anthropocene. IOP Conference Series: Earth and Environmental Science, 25: 012010.
Richter D D, Billings S A. 2015. ‘One physical system’: Tansley’s ecosystem as Earth’s critical zone. New Phytologist, 206(3): 900–912.
Ritchie G S P, Dolling P J. 1985. The role of organic matter in soil acidification. Australian Journal of Soil Research, 23(4): 569–576.
Shi Y, Baumann F, Ma Y, et al. 2012. Organic and inorganic carbon in the topsoil of the Mongolian and Tibetan grasslands: pattern, control and implications. Biogeosciences, 9(6): 2287–2299.
Wang S, Tian X, Liu T, et al. 2014. Irrigation, straw, and nitrogen management benefits wheat yield and soil properties in a dryland agro-ecosystem. Agronomy Journal, 106(6): 2193–2201.
Wickham H. 2009. Ggplot2: Elegant Graphics for Data Analysis. New York: Springer, 180–185.
Wood S. 2017. Mixed GAM computation vehicle with automatic smoothness estimation. R package versions 1.8–22. https://doi.org/CRAN.Rproject.org/package=mgcv.
Wu H, Guo Z, Gao Q, et al. 2009. Distribution of soil inorganic carbon storage and its changes due to agricultural land use activity in China. Agriculture, Ecosystems & Environment, 129(4): 413–421.
Yang Y H, Ji C J, Ma W H, et al. 2012. Significant soil acidification across northern China’s grasslands during 1980s–2000s. Global Change Biology, 18(7): 2292–2300.
Yang Y H, Li P, He H L, et al. 2015. Long-term changes in soil pH across major forest ecosystems in China. Geophysical Research Letters, 42(3): 933–940.
Acknowledgements
This study was supported by the National Basic Research Program of China (2014CB954204) and the National Natural Science Foundation of China (41701099, 31770765).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jin, S., Tian, X. & Wang, H. Hierarchical responses of soil organic and inorganic carbon dynamics to soil acidification in a dryland agroecosystem, China. J. Arid Land 10, 726–736 (2018). https://doi.org/10.1007/s40333-018-0066-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s40333-018-0066-2