Analysis of trends in CO2 emissions from fossil fuel use for farm fieldwork related to harvesting annual crops and hay, changing tillage practices and reduced summerfallow in Canada

The Farm Fieldwork and Fossil Fuel Energy and Emissions (F4E2) model was upgraded and then re-verified using the 1996 Farm Energy Use survey (FEUS). The revised model was used to evaluate trends in fossil fuel-based GHG emissions from 1986 to 2001 by using Agricultural Census data to integrate farm-level simulations over national areas of different land uses and tillage practices. The most significant upgrade was the addition of a sub-model for forage harvesting which was integrated nationally using just the areas in tame hay. Accordingly, F4E2 farm-level simulations for annual crops were integrated over just those farm areas instead of all cropland. National estimates of diesel fuel consumption agreed with FEUS within half a percent. Fossil fuel GHG emissions on Canadian farms dropped by 22% from 1986 to 2001 and by 14% from 1991 to 2001. By far the greatest changes have occurred in the Prairies where the most noticeable shift toward reduced tillage has taken place and in spite of less land in summerfallow. In this analysis, the net effect of those measures which increase soil carbon sequestration is toward reduced fossil fuel GHG emissions and energy consumption on Canadian Farms.