Consequently, there is a great GHG burden from intensively
managed vegetable fields. Vegetable fields have a minor potential
to increase SOC because the majority of the vegetable crop biomass
is removed from the fields as compared with highyield
grain crop agriculture, which is responsible for increased SOC
in soils due to an increase in the annual input of the crop residue C
in soils Agriculture is generally
considered to have great potential to reduce GHG emissions and
increase C sinks with fertilizer application facilitating
atmospheric CO2 sequestration into the soil .
Moreover, vegetable crops are fertilized at N rates that exceed those
required for maximum yields, and the percentage of N2O that is
emitted directly or indirectly from N fertilizer becomes increasingly
variable . Frequent tillage for
vegetable production tends to increase microbial activity and
accelerate soil C or N cycling compared with minimal or no-tillage
. Aside from N fertilization, production and
transport of N fertilizer also generate a substantial proportion of the
GHG emissions (e.g., CO2 and N2O) associated with crop production
If indirect N2O emissions due to excess fertilizer
N usage are taken into account, the N2O burden would be higher
than the present estimation emphasized that the sum of direct and indirect N2O emissions
amounted to 3e5% of all fertilizer N used.