Greenhouse gas emissions were estimated from the production
and application of fertilizers, herbicides and pesticides, burning
and fossil fuels used during cultivation practices. Information was
obtained from interviews of sugarcane farmers for the whole
period of sugarcane planting. For fertilizer, both chemical and
organic forms were applied. N2O emissions (direct and indirect)
from the amount of N applied were estimated (IPCC, 2006). CO2
emissions from urea use were accounted for by using the IPCC
emission factor (IPCC, 2006). For field burning, greenhouse gas
emissions were based on the area and the fraction of the field area
that practiced burning using country specific emission factors
(Table 1). These included residue to crop ratio, dry matter fraction,
fraction burn in field (Garivait, 2005). The percentages of sugarcane
burned were analyzed from farmer interviews (68.5% of sugarcane
biomass was burned; 30.8% from pre-harvest and 37.7% from postharvest).
CO2 emissions from biomass burning were not accounted
for because itwas assumed that CO2 is re-absorbed when sugarcane
plants are regrown in the next cropping season. For fossil fuel,
gasoline and diesel used in insecticides application, tillage, irrigation
and sugarcane transportation from sugarcane farm to sugar
mill were considered. The emissions were basically estimated from