Ontario Crop Trends Show Growth Through Ups and Downs

Originally published on June 27, 2024, on Farmtario

By Alfons Weerlink and Roy Ahiati

The 2024 cropping year is well underway. Projecting future yields can help in planning decisions ranging from fertilizer needs to forward contracting levels. This article looks at trends in the average in Ontario crop yields and the variability in those trends over time.

Average Yields

Provincial average yields from 1981 through to 2023 are illustrated in Figure 1 by the solid lines for corn (blue line), soybeans (red line), and winter wheat (green line).

The highest yields for each crop have been obtained in the last several years. For example, average provincial corn yield was 170.9 bushels per acre (bu./ac.) in 2023 and the maximum occurred in 2021 at 175.2 bu./ac. Last year’s soybean yield of 51.4 bu./ac. was just below the peak of 51.6 bu./ac. that also happened in 2021. The highest average winter wheat yield for the province was in 2022 at 96.5 bu./ac.

These recent yields are significantly higher than the average yield over the last 42 years, which are 131 bu./ac. for corn, 40 for soybeans and 70 for winter wheat.

Trends in Yield

The increase in yield growth is estimated through a linear trend line and these are represented by the dashed lines in Figure 1. Based on the slope of this trend equation, Ontario corn yields have increased by an average of just over two bu./ac. per year over the last 42 years.

This trend rate of growth is the same as that for the U.S. average corn yield, according to research conducted by Scott H. Irwin, an agricultural economist with the University of Illinois in 2024. The average annual increase in yield is 0.4 bu./ac. for soybeans and just under one bu./ac. for winter wheat. Although these values are smaller than for corn, the relative changes when expressed in percentages are similar.

In addition to estimating the trend line for the whole period, one was calculated for each decade. The average yield for that decade along with the estimated average annual increase in yield over those 10 years is listed in Table 1.

Despite experiencing the highest absolute yields, the trend increase in yield over the last dozen years is lower than previous decades for corn and soybeans. The decline suggests there has been a potential slowdown in productivity. However, a similar decline in the trend has been observed in the U.S., and Irwin found that the reduction in the rate of increase was because of poorer than average weather conditions and not due to a technological slowdown.

Variability in Yield

Yield deviations from the trend line indicate whether actual yield was above or below trend expectations for each year. For example, the projected corn yield for 2023 was 174.1 bu./ac. Since actual yield was 170.9 bu./ac., actual production was below trend by 3.2 bu./ac.

Such a negative deviation occurred 17 times since 1981 for corn and soybeans while positive deviations occurred 24 times.

The percentage deviation from the trend for the three crops is plotted in Figure 2 since 1981. The extent of the variation around the trend line has decreased over the last 15 years.

Compared to prior years, there were no years where yield was less than 10 per cent below the trend line and two-thirds of the years had yields above projected yield expectation. In contrast, there were four years between 1981 and 2008 when actual yields were significantly more than 10 per cent below trend for each of the three crops.

Projections for 2024

The 2024 Ontario crop yields, based on how those average yields have evolved over time, are projected to be 176.1 bu./ac. for corn, 49.1 for soybeans, and 91.5 for winter wheat. These trend estimates are based on “normal” weather conditions and actual yields will depend on rainfall and temperature during the growing season.

Alfons Weerlink and Roy Ahiati are researchers in the University of Guelph’s department of food, agricultural and resource economics.