Sizing up the 2022 Drought Situation
By David Widmar
You never know when, but each summer, lightning bugs show up in the Midwest. Similarly, you can also count on the drought monitor map to light up social media every summer. We’ve observed two major flaws with most discussions around drought maps. First, the base rate is rarely presented. In other words, how many corn acres are typically in drought conditions at a given time of year? Second, there is little discussion about the relationship between drought conditions and final national yields. While we intuitively know that – at the field level at least – drought conditions adversely affect yields, how does drought map data line up with national yields?
Figure 1 shows the estimated share of corn acres that are in dry (in blue) and drought (in orange) conditions. For the second week of July, an estimated 52% of the corn crop was shaded by some color on the drought monitor map. More specifically, 22% of acres are in dry conditions (22%), and 31% are in some degree of drought.
Since 2000, we can see that every year some share of the U.S. corn crop is experiencing drought. Even in 2004, when yields were a record +18.1 bushels from the trend line, a small share of the crop was in drought. On average, 14% of the crop is in dry conditions, while another 16% is in drought conditions. I think most people would be surprised to hear that an average of 30% of the corn crop experiences some degree of dry or drought conditions in early July. (In the same line of thinking, millions of corn acres also yield poorly every year).
Compared to 2021, a smaller share of the corn crop is experiencing a drought condition (31% versus 38%), while a considerably larger share (22% versus 11%) is in dry conditions (Table 1).
How significant are 2022 drought conditions? Arguably in the top 5 of drought/dry conditions since 2000, but a long shot from 2012 conditions. That year, nearly 75% of the U.S. corn crop was in drought, with another 17% dry. We’ll talk about potential yield implications shortly.
Figure 1. Estimated Share of U.S. Corn Acres in Dry or Drought Conditions, Second Week of July 2000-2021. Data Source: The National Drought Mitigations Center, USDA NASS, aei.ag Calculations.
Figure 2 and Table 2 present the current and past estimates for the soybean crop and drought conditions. For 2022, 24% of acres are dry, and another 23% are in drought conditions, both above the long-term average. Similarly, conditions are among the driest but nowhere near 2012 extremes.
Figure 2. Estimated Share of U.S. Soybean Acres in Dry or Drought Conditions, Second Week of July 2000-2021. Data Source: The National Drought Mitigations Center, USDA NASS, aei.ag Calculations.
The last point to consider is the relationship between these drought measures and national yields. Figure 3 shows the annual departure from trend for corn yields and the share of acres in drought conditions. First, keep in mind that 2012 has a huge effect on the slope of that trend line. Second, there isn’t much of a conclusion that can be made. For instance, in 2005 and 2006, conditions were similar, but yields were above the trend line. Also, there are several years with a little drought effect, yet yields were below trend. The main idea here is that there is more that goes into the size of the U.S. corn crop than the drought monitor maps in July.Figure 3. Relationship between Final Corn Yields and Mid-July Drought Conditions. Data Source: The National Drought Mitigations Center, USDA NASS, aei.ag Calculations.
Wrapping it Up
It’s important to use caution when drawing conclusions about the national yield potential by simply glancing at a drought map. For 2022, we found that an above-average share of the U.S. corn and soybean crop are in dry and drought conditions. Even with that information, however, it is difficult – if not impossible – to draw conclusions about national yields from these data.
For most of us, the drought monitor maps can be distortive to our thinking.
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