TY - JOUR
T1 - Gross N transformation rates and related N2O emissions in Chinese and UK agricultural soils
AU - Zhu, Gaodi
AU - Song, Xiaotong
AU - Ju, Xiaotang
AU - Zhang, Jinbo
AU - Muller, Christoph
AU - Sylvester-Bradley, Roger
AU - Thorman, Rachel
AU - Bingham, IJ
AU - Rees, RM
PY - 2019/5/20
Y1 - 2019/5/20
N2 - The properties of agricultural soils in various regions of the world are variable and can have a significant but poorly understood impact on soil nitrogen (N) transformations and nitrous oxide (N2O) emissions. For this reason, we undertook a study of gross N transformations and related N2O emissions in contrasting agricultural soils from China and the UK. Seven Chinese and three UK agricultural soils were collected for study using a 15N tracing approach. The soil pH ranged from 5.4 to 8.7, with three acidic soils collected from Jinjing, Lishu and Boghall; one neutral soil collected from Changshu, and the other six alkaline soils collected from Quzhou, Zhangye, Changwu, Jinzhong, Boxworth and Stetchworth. Our results showed that the main N transformation processes were oxidation of ammonium (NH4+) to nitrate (NO3−) (ONH4), and mineralization of organic N to NH4+. The gross autotrophic nitrification rates calculated in the three acidic soils were between 0.25 and 4.15 mg N kg−1 d−1, which were significantly lower (p < 0.05) than those in the remaining neutral and alkaline soils ranging from 6.94 to 14.43 mg N kg−1 d−1. Generally, soil pH was positively correlated (p < 0.001) with gross autotrophic nitrification rate and cumulative N2O emissions, indicating that soil pH was an important factor regulating autotrophic nitrification and N2O emissions. There was also a significant positive correlation between the gross autotrophic nitrification rate and cumulative N2O emissions, highlighting the importance of this process for producing N2O emissions in these agricultural soils under aerobic conditions. Gross NH4+ immobilization rates were very low in most soils except for the Jinjing soil with the lowest pH. In conclusion, the gross autotrophic nitrification rates and related N2O emissions were controlled by soil pH irrespectively of the soil's origin in these agricultural soils.
AB - The properties of agricultural soils in various regions of the world are variable and can have a significant but poorly understood impact on soil nitrogen (N) transformations and nitrous oxide (N2O) emissions. For this reason, we undertook a study of gross N transformations and related N2O emissions in contrasting agricultural soils from China and the UK. Seven Chinese and three UK agricultural soils were collected for study using a 15N tracing approach. The soil pH ranged from 5.4 to 8.7, with three acidic soils collected from Jinjing, Lishu and Boghall; one neutral soil collected from Changshu, and the other six alkaline soils collected from Quzhou, Zhangye, Changwu, Jinzhong, Boxworth and Stetchworth. Our results showed that the main N transformation processes were oxidation of ammonium (NH4+) to nitrate (NO3−) (ONH4), and mineralization of organic N to NH4+. The gross autotrophic nitrification rates calculated in the three acidic soils were between 0.25 and 4.15 mg N kg−1 d−1, which were significantly lower (p < 0.05) than those in the remaining neutral and alkaline soils ranging from 6.94 to 14.43 mg N kg−1 d−1. Generally, soil pH was positively correlated (p < 0.001) with gross autotrophic nitrification rate and cumulative N2O emissions, indicating that soil pH was an important factor regulating autotrophic nitrification and N2O emissions. There was also a significant positive correlation between the gross autotrophic nitrification rate and cumulative N2O emissions, highlighting the importance of this process for producing N2O emissions in these agricultural soils under aerobic conditions. Gross NH4+ immobilization rates were very low in most soils except for the Jinjing soil with the lowest pH. In conclusion, the gross autotrophic nitrification rates and related N2O emissions were controlled by soil pH irrespectively of the soil's origin in these agricultural soils.
KW - Chinese agricultural soils
KW - Gross N transformation
KW - N O emissions
KW - N tracing approach
KW - Soil pH
KW - UK agricultural soils
UR - http://www.scopus.com/inward/record.url?scp=85061779192&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2019.02.241
DO - 10.1016/j.scitotenv.2019.02.241
M3 - Article
C2 - 30798228
SN - 0048-9697
VL - 666
SP - 176
EP - 186
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -