Regression modeling of field emissions in wheat production using a life cycle assessment (LCA) approach

Field emissions of Irianian wheat production were investigated. Data were collected from 260 farms from the city of Fereydonshahr in the Esfahan province. Life cycle assessment (LCA) methodology was developed to assess environmental impacts associated with the production of wheat in the studied region. Global warming potential (GWP), eutrophication potential (EP), human toxicity potential (HTP), terrestrial eco-toxicity potential (TEP), oxidant formation potential (OFP) and acidification potential (AP) were calculated as 2620.86 kg CO2 eq.t-1 (tonne of grain), 14.25 kg PO4-2 eq.t-1, 1111.7 kg 1,4-DCB eq.t-1, 10.59 kg 1,4-DCB eq.t-1, 0.0073 kg ethylene eq.t-1 and 19.07 kg SO2 eq.t-1, respectively. In order to specify a relationship between input materials and field emissions (direct and indirect emission), the Cobb-Douglass production function was applied. The impacts of farm area, N, P2O5, K2O, diesel fuel and biocides were entered as independent variables and different impact categories as dependent variables. RMSE of models for GWP, EP, HTP, TEP, OFP and AP was 0.07, 0.19, 0.17, 0.34, 0.49 and 0.26, respectively. Accordingly with a rise in farm size level, the emissions per tonne of grain produced decreased. Accordingly, large farms are more environmentally friendly due to more yields and less emissions per tonne of grains.