Organophosphorus pesticides (OPPs) are a set of toxic persistent organic pollutants (POPs) present in the environment. Recently

biochar-mediated bioremediation has exhibited many advantages over conventional methods for the remediation of pesticide-contaminated soil. In the present study

biochar and nitrogen fertilizer (NH

4

NO

3

) were employed to remediate OPP-contaminated soil and the greenhouse gas (GHG) emission during 90 days of incubation was investigated. After thermal desorption treatment

the content of organophosphorus pesticides reduced from 175.61 μg·kg

-1

to 62.68 μg·kg

-1

. The addition of NH

4

NO

3

in the following bioremediation led to larger reduction (34.35%) of the pesticide concentration than that of biochar (31.90%) for the contaminated soils with thermal desorption treatment

while the simultaneous addition of biochar and NH

4

NO

3

led to the largest reduction of pesticide concentration (11.07%) for the soil without thermal desorption treatment. The addition of biochar and NH

4

NO

3

only slightly increased the emission rate of GHGs

from the soil without thermal treatment

but remarkably increased the emission rate of GHGs from the soil after thermal treatment. In most cases

the addition of NH

4

NO

3

is more effective than biochar to promote the degradation of pesticide

but also exhibited higher GHG emission. The microbial community analysis suggests that the enhanced degradation of pesticide is mainly owing to the increased activity of microorganism.