Details
| Original language | English |
|---|---|
| Pages (from-to) | 2810-2817 |
| Number of pages | 8 |
| Journal | Global change biology |
| Volume | 24 |
| Issue number | 7 |
| Publication status | Published - Jul 2018 |
| Externally published | Yes |
Abstract
Nitrogen (N) fertilization is an indispensable agricultural practice worldwide, serving the survival of half of the global population. Nitrogen transformation (e.g., nitrification) in soil as well as plant N uptake releases protons and increases soil acidification. Neutralizing this acidity in carbonate-containing soils (7.49 × 109 ha; ca. 54% of the global land surface area) leads to a CO2 release corresponding to 0.21 kg C per kg of applied N. We here for the first time raise this problem of acidification of carbonate-containing soils and assess the global CO2 release from pedogenic and geogenic carbonates in the upper 1 m soil depth. Based on a global N-fertilization map and the distribution of soils containing CaCO3, we calculated the CO2 amount released annually from the acidification of such soils to be 7.48 × 1012 g C/year. This level of continuous CO2 release will remain constant at least until soils are fertilized by N. Moreover, we estimated that about 273 × 1012 g CO2-C are released annually in the same process of CaCO3 neutralization but involving liming of acid soils. These two CO2 sources correspond to 3% of global CO2 emissions by fossil fuel combustion or 30% of CO2 by land-use changes. Importantly, the duration of CO2 release after land-use changes usually lasts only 1–3 decades before a new C equilibrium is reached in soil. In contrast, the CO2 released by CaCO3 acidification cannot reach equilibrium, as long as N fertilizer is applied until it becomes completely neutralized. As the CaCO3 amounts in soils, if present, are nearly unlimited, their complete dissolution and CO2 release will take centuries or even millennia. This emphasizes the necessity of preventing soil acidification in N-fertilized soils as an effective strategy to inhibit millennia of CO2 efflux to the atmosphere. Hence, N fertilization should be strictly calculated based on plant-demand, and overfertilization should be avoided not only because N is a source of local and regional eutrophication, but also because of the continuous CO2 release by global acidification.
Keywords
- CO efflux, global acidification assessment, global warming, mitigation policy, nitrogen fertilization, soil acidification mechanisms, soil inorganic carbon
ASJC Scopus subject areas
- Environmental Science(all)
- Global and Planetary Change
- Environmental Science(all)
- Environmental Chemistry
- Environmental Science(all)
- Ecology
- Environmental Science(all)
- General Environmental Science
Sustainable Development Goals
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In: Global change biology, Vol. 24, No. 7, 07.2018, p. 2810-2817.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Nitrogen fertilization raises CO2 efflux from inorganic carbon
T2 - A global assessment
AU - Zamanian, Kazem
AU - Zarebanadkouki, Mohsen
AU - Kuzyakov, Yakov
N1 - Funding information: We acknowledge German Research Foundation (DFG) for their sup-
PY - 2018/7
Y1 - 2018/7
N2 - Nitrogen (N) fertilization is an indispensable agricultural practice worldwide, serving the survival of half of the global population. Nitrogen transformation (e.g., nitrification) in soil as well as plant N uptake releases protons and increases soil acidification. Neutralizing this acidity in carbonate-containing soils (7.49 × 109 ha; ca. 54% of the global land surface area) leads to a CO2 release corresponding to 0.21 kg C per kg of applied N. We here for the first time raise this problem of acidification of carbonate-containing soils and assess the global CO2 release from pedogenic and geogenic carbonates in the upper 1 m soil depth. Based on a global N-fertilization map and the distribution of soils containing CaCO3, we calculated the CO2 amount released annually from the acidification of such soils to be 7.48 × 1012 g C/year. This level of continuous CO2 release will remain constant at least until soils are fertilized by N. Moreover, we estimated that about 273 × 1012 g CO2-C are released annually in the same process of CaCO3 neutralization but involving liming of acid soils. These two CO2 sources correspond to 3% of global CO2 emissions by fossil fuel combustion or 30% of CO2 by land-use changes. Importantly, the duration of CO2 release after land-use changes usually lasts only 1–3 decades before a new C equilibrium is reached in soil. In contrast, the CO2 released by CaCO3 acidification cannot reach equilibrium, as long as N fertilizer is applied until it becomes completely neutralized. As the CaCO3 amounts in soils, if present, are nearly unlimited, their complete dissolution and CO2 release will take centuries or even millennia. This emphasizes the necessity of preventing soil acidification in N-fertilized soils as an effective strategy to inhibit millennia of CO2 efflux to the atmosphere. Hence, N fertilization should be strictly calculated based on plant-demand, and overfertilization should be avoided not only because N is a source of local and regional eutrophication, but also because of the continuous CO2 release by global acidification.
AB - Nitrogen (N) fertilization is an indispensable agricultural practice worldwide, serving the survival of half of the global population. Nitrogen transformation (e.g., nitrification) in soil as well as plant N uptake releases protons and increases soil acidification. Neutralizing this acidity in carbonate-containing soils (7.49 × 109 ha; ca. 54% of the global land surface area) leads to a CO2 release corresponding to 0.21 kg C per kg of applied N. We here for the first time raise this problem of acidification of carbonate-containing soils and assess the global CO2 release from pedogenic and geogenic carbonates in the upper 1 m soil depth. Based on a global N-fertilization map and the distribution of soils containing CaCO3, we calculated the CO2 amount released annually from the acidification of such soils to be 7.48 × 1012 g C/year. This level of continuous CO2 release will remain constant at least until soils are fertilized by N. Moreover, we estimated that about 273 × 1012 g CO2-C are released annually in the same process of CaCO3 neutralization but involving liming of acid soils. These two CO2 sources correspond to 3% of global CO2 emissions by fossil fuel combustion or 30% of CO2 by land-use changes. Importantly, the duration of CO2 release after land-use changes usually lasts only 1–3 decades before a new C equilibrium is reached in soil. In contrast, the CO2 released by CaCO3 acidification cannot reach equilibrium, as long as N fertilizer is applied until it becomes completely neutralized. As the CaCO3 amounts in soils, if present, are nearly unlimited, their complete dissolution and CO2 release will take centuries or even millennia. This emphasizes the necessity of preventing soil acidification in N-fertilized soils as an effective strategy to inhibit millennia of CO2 efflux to the atmosphere. Hence, N fertilization should be strictly calculated based on plant-demand, and overfertilization should be avoided not only because N is a source of local and regional eutrophication, but also because of the continuous CO2 release by global acidification.
KW - CO efflux
KW - global acidification assessment
KW - global warming
KW - mitigation policy
KW - nitrogen fertilization
KW - soil acidification mechanisms
KW - soil inorganic carbon
UR - http://www.scopus.com/inward/record.url?scp=85045406817&partnerID=8YFLogxK
U2 - 10.1111/gcb.14148
DO - 10.1111/gcb.14148
M3 - Article
C2 - 29575284
AN - SCOPUS:85045406817
VL - 24
SP - 2810
EP - 2817
JO - Global change biology
JF - Global change biology
SN - 1354-1013
IS - 7
ER -