REES Brown Bag Seminar: Jiansong Xu, Thursday, May 4, 2023

Title:  The adoption of semidwarf wheat and the associated N2O emissions

Speaker: Jiansong Xu, PhD student, Department of REES

Date: Thursday, May 4, 2023

Location:  550 General Services Building

Time: 3:30 – 4:30 PM

Abstract: 

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. We study 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 (N 2 O) emissions when farmers adopt semidwarf wheat and subsequently change nitrogen
rates. The results suggest 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 N 2 O 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 N 2 O
emissions induced by nitrogen fertilizer applied to Saskatchewan spring wheat would increase by at
least $0.29 millions of CAD.