EVALUATING ECONOMICS OF GREENHOUSE GAS EMISSION UNDER HIGH AND LOW INPUTS FARMING SYSTEM

A serious concern about the sustainability of existing production systems has resulted from the low profitability of agriculture and the deterioration of the natural resource base. As a result of these concerns, increased attention has been given to alternative farming practices in order to decrease the use of fossil fuels, to enhance the efficiency of nitrogen fertilization, and to increase the implementation of conservation tillage practices. Farmers are recommended to include pulse crop into their rotation since legumes form symbiotic associations with bacteria that can fix atmospheric N2 reducing the need of nitrogen fertilizer application and the emission of greenhouse gas (GHG) production. The objective of this study was to evaluate the economics of greenhouse gas mitigation for different cropping systems and management practices. Data from a 5-year study of a wheat-pea rotation, under different seeding systems and fertilizer and herbicide rates, was used to examine economic and greenhouse gas performance. Based on IPCC estimations of nitrous oxide (N2O) emissions, comparisons were made to measured N2O rates to determine if the difference between these figures were significant. Comparison of actual measured N2O emissions to estimations based on IPCC indicated that the measure emission rate was significantly lower than estimated values for the site. Results for low-fertilizer rates, under a low-disturbance system, suggests there is greater net carbon fixed as compared to the high-disturbance practices in both wheat and pea. Overall, the decreased use of fertilizer (50% to 75% of recommended rates) under a low-disturbance seeding-system was preferable, based upon environmental-economic indicators.