A global analysis of soil acidification caused by nitrogen addition

By Dashuan Tian, Shuli Niu. 2015

1,004 citations recorded by the source corpus.

Nitrogen (N) deposition-induced soil acidification has become a global problem. However, the response patterns of soil acidification to N addition and the underlying mechanisms remain far from clear. Here, we conducted a meta-analysis of 106 studies to reveal global patterns of soil acidification in responses to N addition. We found that N addition significantly reduced soil pH by 0.26 on average globally. However, the responses of soil pH varied with ecosystem types, N addition rate, N fertilization forms, and experimental durations. Soil pH decreased most in grassland, whereas boreal forest was not observed a decrease to N addition in soil acidification. Soil pH decreased linearly with N addition rates. Addition of urea and NH4NO3 contributed more to soil acidification than NH4-form fertilizer. When experimental duration was longer than 20 years, N addition effects on soil acidification diminished. Environmental factors such as initial soil pH, soil carbon and nitrogen content, precipitation, and temperature all influenced the responses of soil pH. Base cations of Ca2+, Mg2+ and K+ were critical important in buffering against N-induced soil acidification at the early stage. However, N addition has shifted global soils into the Al3+ buffering phase. Overall, this study indicates that acidification in global soils is very sensitive to N deposition, which is greatly modified by biotic and abiotic factors. Global soils are now at a buffering transition from base cations (Ca2+, Mg2+ and K+) to non-base cations (Mn2+ and Al3+). This calls our attention to care about the limitation of base cations and the toxic impact of non-base cations for terrestrial ecosystems with N deposition.

Subfields: Biomaterials, Civil and Structural Engineering, Soil Science

View Paper: https://www.semanticscholar.org/paper/5051e4e4d9114f3944964ba07488774c1aa97111

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Citations in the corpus

Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity (2016, background): “Moreover, the excess N that can’t be absorbed by plants will cause serious environmental problems, such asN leaching,N2Oemission and soil acidification (Lu et al 2011a, Shcherbak et al 2014, Tian & Niu 2015).”
Plant diversity enhances productivity and soil carbon storage (2018, background): “139 High N deposition increases soil acidity (47).”
Global change effects on humid tropical forests: Evidence for biogeochemical and biodiversity shifts at an ecosystem scale (2016, result): “The average pH decrease across the sites globally was 0.26 units, with similar declines in the tropical forest sites [Tian and Niu, 2015].”
Modeling Soil Processes: Review, Key Challenges, and New Perspectives (2016, background): “Major inputs of, for example, nitrogen to the soil system may affect the soil’s pH, leading to acidification and changes in its buffering capacity (Guo et al., 2010; Tian and Niu, 2015).”
Effects of biochar application on root traits: a meta‐analysis (2017, background): “More available inorganic N sources under N fertilization could limit the root uptake of P due to nutrient imbalance and soil acidification (Vitousek et al., 2010; Tian & Niu, 2015).”
Conceptualizing soil organic matter into particulate and mineral‐associated forms to address global change in the 21st century (2019, background): “…SOM processing driven by C and N stoichiometry of inputs (Mooshammer, Wanek, Hämmerle, et al., 2014; Mooshammer, Wanek, Zechmeister‐Boltenstern, et al., 2014), changes in microbial community structure (Averill et al., 2018), and changes in pH that can coincide with N additions (Tian & Niu, 2015).”