Effect of controlled drainage in the wheat season on soil CH4 and N2O emissions during the rice season

Document Type: Research Paper

Authors

1 Anhui Agriculture University, Hefei, Anhui, China.

2 Anhui Agriculture University, Hefei, Anhui, China

3 Anhui Agriculture University, Hefei, Anhui, China Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, PO Box 123, Broadway, NSW 2007, Australia.

Abstract

The effect of draining crop fields during the wheat season on the soil CH4 and
N2O emissions during the rice season in this article. There were four treatments:
traditional cultivation during the wheat season + cultivation without fertilization
during the rice season (CK1 field), traditional cultivation during the wheat season +
traditional cultivation during the rice season (CK2 field), draining the fields through
shallow furrows + traditional cultivation during the rice season (CQ field) and
draining the fields through deep furrows + traditional cultivation during the rice
season (CS field). The results are listed as follows. (1) Draining the field through
furrows during the wheat season significantly reduced the CH4 and N2O emissions
during the rice season. Compared with the CK1 field, the total CH4 emissions from
the CQ and CS fields decreased by 43.1% and 39.9%, respectively; compared with
the CK2 field, the total CH4 emissions from the CQ and CS fields decreased by
58.1% and 55.7%, respectively; compared with the CK2 field, the total N2O
emissions from the CQ and CS fields decreased by 33.6% and 32.7%, respectively.
N2O emissions from the CQ and CS fields caused by fertilization declined by
44.0% and 42.9% compared with that from the CK2 field. (2) Draining the wheat
field in winter changed the CH4 emission pattern during the following rice season.
The daily average CH4 emission flux from the winter flooded CK1 and CK2 fields
were comparable before the field sunning and after the re-flooding and the fluxes
from the drained CQ and CS fields before the field sunning were close to that from
the CK1 and CK2 fields but were significantly greater than that from the drained
CQ and CS fields after the field re-flooding. (3) The soil CH4 emission flux was significantly negatively correlated to the soil Eh. But the correlation was weakened
by the drainage treatment in the wheat season. In summary, draining the crop field
in the wheat season should be an effective approach to reducing soil greenhouse
gas emissions in the rice season.




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