After the Green Revolution, semidwarf varieties of wheat increased in popularity worldwide. With an increase in lodging resistance and higher responsiveness to nitrogen, farmers have the ability to apply more nitrogen to achieve higher yields. However, while semidwarf varieties are favorable to farmers seeking to increase productivity, the net change in greenhouse gas emissions resulting from the increased use of nitrogen fertilizer remains underexplored. This thesis studies the joint determination of semidwarf variety selection and nitrogen use in Saskatchewan, Canada—one of the leading provinces in wheat production. We develop a Control Function (CF) model to estimate the joint choices of semidwarf wheat varieties and nitrogen application rates using field-level data of Saskatchewan farms between 2011 and 2019. After that, we employ emission factors from the literature to estimate
changes in direct nitrous oxide (N2O) emissions when farmers adopt
semidwarf wheat and subsequently change nitrogen rates. Our regres-
sion model suggests a 5.9% expected increase in nitrogen application rate when a farmer switches from conventional to semidwarf wheat. The subsequent analysis suggests that although semidwarf wheat generally has higher nitrogen application rates than conventional wheat, their fertilizer-induced direct N2O emissions per tonne of grain production are fairly similar. Based on the adoption status of semidwarf wheat and conventional wheat in 2019, if all conventional wheat acres in Saskatchewan switch to semidwarf wheat, the value of environmental damage associated with the direct N2O emissions induced by nitrogen fertilizer applied to Saskatchewan spring wheat would increase by at least $0.29 millions of CAD
