Using a socioecological metabolism approach to analyze data from the Census of Agriculture, this article examines the underlying soil fertility of two case study areas in the Canadian province of Saskatchewan through the calculation of soil nitrogen balances. The Rural Municipalities of Wise Creek and Livingston are 300 miles apart and therefore have different topography, soil types, and rainfall levels, even though both are within the northern Great Plains. Over 85 years, from first settlement in the 1910s until the beginning of the twenty-first century, Wise Creek agriculture focused increasingly on livestock production while in Livingston farmers began to grow a greater variety of crops, most notably incorporating canola into rotations. Despite the differences between the two case studies, the pattern of soil nitrogen losses was remarkably similar, with biomass yields declining along with soil nitrogen. The addition of chemical nitrogen fertilizers since the 1960s did not produce yields matching historic highs, nor did a renewed focus on livestock. Wise Creek and Livingston showed two different responses to declining yields, but neither one ultimately provided a long-term solution to the problem of soil nutrient depletion and consequent productivity declines.