Spatiotemporal changes in greenhouse gas emissions and soil organic carbon sequestration for major cropping systems across China and their drivers over the past two decades

Copyright © 2022 Elsevier B.V. All rights reserved..

Chinese agricultural systems have experienced dramatic changes in crop planting area, cropping system, irrigation and fertilization managements, and crop yields in recent decades. These changes can substantially affect greenhouse gases (GHG) emissions and soil organic carbon (SOC) sequestration in croplands. However, the spatiotemporal patterns, as well as their driving factors and mechanisms, have not been well understood. Here, the Denitrification-Decomposition model is calibrated and validated to estimate nitrous oxide (N2O) and methane (CH4) emissions and SOC sequestration for seven major cropping systems in China during 2001-2020. The Logarithmic Mean Divisia Index method is further applied to attribute the net GHG emissions (NGEs) trend to various drivers. The results show that the total N2O emissions, CH4 emissions, and SOC sequestration were approximately 23.7, 182.0, and 177.6 Tg CO2-eq/year in the croplands across China. The national average NGEs per unit area ranged from -8705 to 8431 kg CO2-eq ha-1 year-1 across the major cropping systems. During 2001-2020, the trend in national annual NGEs was 0.66 kg CO2-eq ha-1 year-2, ranging from -78.9 to 82.2 kg CO2-eq ha-1 year-2 across the major cropping systems. The paddy lands were mainly a carbon source due to the large amount of CH4 emissions while the uplands could be a carbon sink owing to SOC sequestration. As a whole, the cropland in China was a carbon source with the NGEs equal to 28.4 Tg CO2-eq/year, and the NGEs increased by 0.047 Tg CO2-eq/year2 in the past 20 years. Nationally, changes in crop planting area and yields reduced the NGEs whereas changes in nitrogen use efficiency and cropping systems increased them, although the major factors and their impacts varied greatly among regions. Optimizing cropping systems and nitrogen fertilization based on the local genotype, environment and management should be the most effective method to reduce the NGEs in croplands.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:833

Enthalten in:

The Science of the total environment - 833(2022) vom: 10. Aug., Seite 155087

Sprache:

Englisch

Beteiligte Personen:

Wang, Yicheng [VerfasserIn]
Tao, Fulu [VerfasserIn]
Yin, Lichang [VerfasserIn]
Chen, Yi [VerfasserIn]

Links:

Volltext

Themen:

142M471B3J
7440-44-0
Agricultural system
Carbon
Carbon Dioxide
Carbon cycle
Climate smart agriculture
GHG emissions
Greenhouse Gases
Journal Article
K50XQU1029
Methane
Mitigation
N762921K75
Nitrogen
Nitrous Oxide
OP0UW79H66
SOC
Soil

Anmerkungen:

Date Completed 03.06.2022

Date Revised 03.06.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.scitotenv.2022.155087

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM339509651