Conversion from rice to vegetable production increases N2O emission via increased soil organic matter mineralization

Copyright © 2017 Elsevier B.V. All rights reserved..

The conversion from rice to vegetable production widely occurs in China. However, the effects of this conversion on N2O emission and the underlying mechanisms are not well understood. In the present study, 12 rice paddies (R) were selected and half of them converted to vegetable fields (V) with the following treatments: rice paddies without N-fertilizer (R-CK), rice paddies with conventional N-fertilizer (R-CN), converted vegetable fields without N-fertilizer (V-CK), and converted vegetable fields with conventional N-fertilizer (V-CN) in a randomized block design with 3 replicates. N2O emissions were measured with static chambers from December 2012 to December 2015. Within each V-CN plot, a root exclusion subplot was established to measure soil heterotrophic respiration (CO2 effluxes), a proxy for soil organic matter mineralization. Conversion of rice paddies to vegetable production dramatically increased N2O emissions. The three-year cumulative N2O emissions were 0.59, 1.90, 55.50 and 160.14kg N ha-1 for R-CK, R-CN, V-CK and V-CN, respectively. The annual N2O emissions from vegetable fields ranged between 5.99 and 113.45kg N ha-1yr-1, with substantially higher emissions in the first year. N2O fluxes from V-CN were significantly and positively related to CO2 fluxes and inorganic N concentrations. The linear relationship between natural logarithms of N2O and CO2 fluxes was stronger and the regression coefficient higher in the first year, showing the dependence of N2O on soil organic matter mineralization. These results suggest that soil organic matter and N mineralization contributes significantly to N2O emission following conversion of rice paddies to vegetable production.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:583

Enthalten in:

The Science of the total environment - 583(2017) vom: 01. Apr., Seite 190-201

Sprache:

Englisch

Beteiligte Personen:

Wu, Lei [VerfasserIn]
Tang, Shuirong [VerfasserIn]
He, Dongdong [VerfasserIn]
Wu, Xian [VerfasserIn]
Shaaban, Muhammad [VerfasserIn]
Wang, Milan [VerfasserIn]
Zhao, Jingsong [VerfasserIn]
Khan, Imran [VerfasserIn]
Zheng, Xunhua [VerfasserIn]
Hu, Ronggui [VerfasserIn]
Horwath, William R [VerfasserIn]

Links:

Volltext

Themen:

Air Pollutants
Fertilizers
Inter-annual variation
Journal Article
K50XQU1029
Land management change
Nitrous Oxide
Organic matter mineralization
Soil
Soil N(2)O emission

Anmerkungen:

Date Completed 18.05.2018

Date Revised 18.05.2018

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.scitotenv.2017.01.050

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM268284733