TY - JOUR

T1 - Nitrification-induced acidity controls CO2 emission from soil carbonates

AU - Tao, Jingjing

AU - Fan, Lichao

AU - Zhou, Jianbin

AU - Banfield, Callum Colin

AU - Kuzyakov, Yakov

AU - Zamanian, Kazem

N1 - We are very thankful to the China Scholarship Council (CSC) for funding Jingjing Tao during her stay in Germany. Kazem Zamanian thanks the German Research Foundation (DFG, ZA 1068/4), Ministry of Science and Culture of Lower-Saxony, Germany (15-76251-2—Stay-8/22–5947/2022). Jianbin Zhou thanks the National Natural Science Foundation of China (41671295). Yakov Kuzyakov thanks the Russian Science Foundation for the project 19-77-30012, the RUDN University Strategic Academic Leadership Program, and Strategic Academic Leadership Program "Priority 2030" of the Kazan Federal University. Lichao Fan thanks to Restoration Project of Mountains, Rivers, Forests, Fields, Lakes, Grasslands and Deserts in the Northern Foothills of Qinling in Shaanxi Province (2203-610100-04-05-321562).

PY - 2024/5

Y1 - 2024/5

N2 - Nitrification acidifies soil, and the produced H + are neutralized by inorganic carbon (C) in soil leading to irreversible CO 2 emissions. CO 2 released by nitrogen (N) fertilizer-induced acidification is partitioned between solid (CaCO 3 re-precipitation), liquid (dissolved HCO 3 − and CO 3 2−) and gaseous (CO 2) phases. Therefore, quantifying the effects of N fertilization on CO 2 emissions from soil inorganic C is an enormous challenge. 14C-labeled CaCO 3 was used as a model inorganic C to trace the released CO 2 caused by acidification by five fertilizers: chicken manure, urea, KNO 3, NH 4NO 3, and (NH 4) 2SO 4 added at three N rates. Cropland soil was homogenously mixed with Ca 14CO 3 powder and fertilizers, and the emitted CO 2 was trapped in NaOH solution to determine total CO 2 and 14CO 2 efflux originated from inorganic C. Fertilization, particularly ammonium-based fertilizers ((NH 4) 2SO 4, NH 4NO 3), strongly decreased soil pH by 0.35 units over 40 days. All fertilizers except KNO 3 increased total CO 2 emissions by 21%–490% compared to the unfertilized control soil. The fertilization effects on cumulative 14CO 2 emission induced by CaCO 3 neutralization, corresponded to acidification and decreased in the order (NH 4) 2SO 4 > NH 4NO 3 > urea > KNO 3 > chicken manure. Ammonium-based fertilizers induced the strongest CO 2 emissions originated from inorganic C, emitting 1.6–4.5 times more 14CO 2 than non-fertilized soils during the first nine days. The total CO 2 emissions from SIC were proportional to the fertilizer dose applied. Therefore, we conclude that both the choice of N fertilizers and their application rates need to be considered to control CO 2 emissions originated from inorganic C. The soil inorganic C losses should be prevented not only because of their irreversible contribution to atmospheric CO 2, but also to safeguard ecosystem services of CaCO 3, such as organic matter preservation, soil structure stabilization, and C sequestration.

AB - Nitrification acidifies soil, and the produced H + are neutralized by inorganic carbon (C) in soil leading to irreversible CO 2 emissions. CO 2 released by nitrogen (N) fertilizer-induced acidification is partitioned between solid (CaCO 3 re-precipitation), liquid (dissolved HCO 3 − and CO 3 2−) and gaseous (CO 2) phases. Therefore, quantifying the effects of N fertilization on CO 2 emissions from soil inorganic C is an enormous challenge. 14C-labeled CaCO 3 was used as a model inorganic C to trace the released CO 2 caused by acidification by five fertilizers: chicken manure, urea, KNO 3, NH 4NO 3, and (NH 4) 2SO 4 added at three N rates. Cropland soil was homogenously mixed with Ca 14CO 3 powder and fertilizers, and the emitted CO 2 was trapped in NaOH solution to determine total CO 2 and 14CO 2 efflux originated from inorganic C. Fertilization, particularly ammonium-based fertilizers ((NH 4) 2SO 4, NH 4NO 3), strongly decreased soil pH by 0.35 units over 40 days. All fertilizers except KNO 3 increased total CO 2 emissions by 21%–490% compared to the unfertilized control soil. The fertilization effects on cumulative 14CO 2 emission induced by CaCO 3 neutralization, corresponded to acidification and decreased in the order (NH 4) 2SO 4 > NH 4NO 3 > urea > KNO 3 > chicken manure. Ammonium-based fertilizers induced the strongest CO 2 emissions originated from inorganic C, emitting 1.6–4.5 times more 14CO 2 than non-fertilized soils during the first nine days. The total CO 2 emissions from SIC were proportional to the fertilizer dose applied. Therefore, we conclude that both the choice of N fertilizers and their application rates need to be considered to control CO 2 emissions originated from inorganic C. The soil inorganic C losses should be prevented not only because of their irreversible contribution to atmospheric CO 2, but also to safeguard ecosystem services of CaCO 3, such as organic matter preservation, soil structure stabilization, and C sequestration.

KW - C-labeled CaCO

KW - N fertilizer

KW - Nitrification

KW - SIC-Originated CO emission

KW - Soil acidification

KW - Soil inorganic carbon

UR - http://www.scopus.com/inward/record.url?scp=85187784531&partnerID=8YFLogxK

U2 - 10.1016/j.soilbio.2024.109398

DO - 10.1016/j.soilbio.2024.109398

M3 - Article

VL - 192

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

SN - 0038-0717

M1 - 109398

ER -