2023 Corn Yield Forecasts as of July 13

2023 Corn Yield Forecasts as of July 13

Simulations of 2023 end-of-season corn yield potential and real-time crop stage were performed on July 13 for 40 locations across the U.S. Corn Belt using the UNL Hybrid-Maize crop model in collaboration with faculty and extension educators from 10 universities. This article summarizes the simulated crop stages and yield forecasts; the data can be found in Table 1. Details on the UNL Hybrid-Maize crop model and the underpinning methodology to simulate phenology and forecast end-of-season yields, as well as on interpretation and uses of yield forecasts, are described in a previous article.

A summary of weather conditions during the last 60 days (from May 13 to July 12) is shown in Figure 1. The season started with warm weather in the central and northwestern regions of the Corn Belt, with temperatures above normal in ND, MN, IL, IA and NE. In south and east areas (KS, MO, IN and OH), temperature records were near the historical averages for most cases. In agreement with drought monitor reports, rainfall was below average across the whole region, except for the western fringe (ND, western NE and KS).

Graph of 2023 daily solar radiation, maximum and minimum air temperature, total rainfall
Figure 1. Daily solar radiation, maximum and minimum air temperature (Tmax and Tmin), total rainfall, and total reference grass-based evapotranspiration (ET) for the time period between May 13 and July 12, 2023. Vertical bars indicate the range for these variables based on 20-plus years of weather records. The horizontal thick line indicates the long-term average and the red dots indicate the 2023 values for the same period.

Table 1. Data from simulations of 2023 end-of-season corn yield potential and real-time crop stage performed on July 12.
LocationWater regimeLong-term average yield (bu/ac) §Range of Yp forecasts as of Jul 19 (bu/ac)¶ 25thRange of Yp forecasts as of Jul 12 (bu/ac)¶ 75thProbability (%) of 2023 yield to be: Below (relative to the long-term Yp)†Probability (%) of 2023 yield to be: Near (relative to the long-term Yp)†Probability (%) of 2023 yield to be: Above (relative to the long-term Yp)†Simulated current crop stage*
NE Alliance Irrigated 193 176 216 21% 44% 35% V8
Beatrice Dryland 160 120 171 48% 27% 24% R1, Silking
Irrigated 229 209 239 24% 70% 6% R1, Silking
Clay Center Dryland 155 67 158 61% 15% 24% V16
Irrigated 245 226 250 15% 76% 10% V16
Concord Dryland 173 155 226 27% 17% 56% V16
Irrigated 248 234 266 15% 71% 15% V16
Elgin Irrigated 252 235 265 11% 74% 14% V16
Holdrege Dryland 112 84 134 37% 23% 40% V14
Irrigated 242 217 249 26% 60% 14% V14
McCook Dryland 86 70 116 29% 7% 63% V14
Irrigated 224 199 231 27% 61% 12% V14
Mead Dryland 181 129 188 51% 32% 17% V18
Irrigated 234 213 242 20% 66% 15% V18
North Platte Dryland 90 110 134 2% 20% 78% V12
Irrigated 234 212 255 22% 54% 24% V12
O'Neill Irrigated 226 209 249 16% 58% 26% V12
IA Ames Dryland 228 198 236 43% 40% 17% V16
Crawfordsville Dryland 227 179 213 58% 39% 3% V18
Lewis Dryland 205 154 207 44% 44% 12% R1, Silking
Nashua Dryland 228 197 224 41% 56% 3% V14
Sutherland Dryland 208 193 225 21% 62% 18% V14
IL Bondville Dryland 235 222 259 13% 58% 29% V16
Freeport Dryland 213 164 225 42% 42% 15% V14
Olney Dryland 191 190 225 18% 27% 55% R1, Silking
Peoria Dryland 211 214 251 3% 57% 40% V16
Springfield Dryland 182 162 212 30% 35% 35% V18
IN Butlerville Dryland 224 209 237 10% 70% 20% V14
Columbia City Dryland 224 217 251 0% 60% 40% V12
Davis Dryland 230 237 262 0% 50% 50% V12
West Lafayette Dryland 236 222 242 10% 80% 10% V14
KS Garden City Irrigated 217 204 236 19% 62% 19% V14
Hutchinson Dryland 99 83 119 36% 12% 52% R2, Blister
Manhattan Dryland 137 134 169 16% 37% 47% R1, Silking
Scandia Dryland 129 71 119 73% 14% 14% R1, Silking
Irrigated 226 202 244 27% 51% 22% R1, Silking
Silverlake Dryland 141 111 167 41% 24% 35% R1, Silking
Irrigated 209 191 229 19% 57% 24% R1, Silking
MI Ceresco Dryland 180 167 222 14% 32% 55% V8
MN Eldred Dryland 114 51 108 67% 19% 15% V10
Lamberton Dryland 212 197 226 19% 65% 15% V16
Waseca Dryland 219 196 230 28% 63% 9% V16
MO Brunswick Dryland 181 97 131 91% 9% 0% R1, Silking
Monroe City Dryland 175 99 171 55% 45% 0% V18
St. Joseph Dryland 169 139 187 35% 39% 26% R1, Silking
ND Dazey Dryland 108 108 168 21% 11% 68% V10
OH Custar Dryland 208 214 238 3% 47% 50% V10
South Charleston Dryland 216 192 246 27% 45% 27% V12
Wooster Dryland 210 192 225 24% 58% 18% V8

§Long-term (last 20+ years) potential yield at each location and surrounding area.
¶ Range of forecasted 2023 potential yields based on average planting date in 2023, indicating the potential yields in the 25th and 75th percentile of the potential yield distribution (associated with respective adverse and favorable weather scenarios during the rest of the season).
† Probability of obtaining a 2023 yield below (<-10%), near (±10%), and above (>10%) than the long-term potential yield at each location.

Simulated Corn Stage Across 40 Locations

Corn has not reached silking yet at most sites, except for the southern fringe of the region (Figure 2). Except for MN and ND, where corn development is ahead of last season, most locations are at a stage similar to 2022 at this time of the year.

Figure 2. Simulated developmental stage for irrigated and rainfed corn at each location. Vn: vegetative stage (nth leaf); R1: silking; R2: blister. Separate maps are shown for irrigated corn (top) and rainfed corn (bottom).

Irrigated Corn: High Probability of Near-average Yields

The range of forecasted irrigated corn yield potential for each location, as well as the probabilities for yields above, near or below average, are shown in Figures 3 and 4. Although it is still too early in the season, there is a relatively high probability of near-average yields for all sites. Indeed, there is a high probability of near-average yield (>75%, that is, a chance of three out of four) in south and central NE. Weather conditions during the rest of the growing season will determine if most irrigated sites will yield near average.

Variation in 2023 Forecasted Rainfed Corn Yield

Forecasted yield potential is highly variable across rainfed sites (Figures 3 and 4). Overall, at this point of the season, probability of near-average yield is relatively high towards the eastern fringe of the Corn Belt (IL, IN and OH) and southern MN. Conversely, the probability of below-average yields is relatively high in the central, western and southern regions, except for west NE and south KS, which is consistent with USDA NASS crop reports. Precipitation and temperature during the rest of July and early August will determine whether these trends persist or not. If rainfall increases, as has been the case over the past two weeks, we will expect forecasted yields to improve.

Figure 3. Vertical lines indicate the range of forecasted 2023 corn yield potential by July 12 based on average planting date in 2023 at each location. Horizontal lines indicate the 25th and 75th percentiles of the yield distribution (associated with respective adverse and favorable weather scenarios during the rest of the season). The blue squares indicate the long-term (2005-2022) average yield potential at each location. Separate charts are shown for irrigated corn (top) and rainfed corn (bottom).
Figure 4. Probability of the 2023 yield potential to be below (<10%, red color), near (± 10%, yellow color), and above (>10%, green color) the long-term (2005-2022) average yield potential at each location. Separate maps are shown for irrigated corn (top) and rainfed corn (bottom). The larger a color section is within the pie chart, the higher the probability that end-of-season corn yield will be in that category.

Conclusions

Corn is still in vegetative stages throughout most of the region. Although it is still too early to make strong inferences about end-of-season yields for irrigated corn, there is a relatively high probability for near-average yields for most sites, but this can change depending upon temperature during the next four weeks.

For rainfed corn, the scenario is diverse across regions, with high probability of below-average yields in the south, central and western regions of the Corn Belt due to below-average rainfall. Temperature and rainfall during the rest of July and early August will be critical to understand if the current projections will persist.

These forecasts do not take into consideration problems with stand emergence, hail/flooding damage, replanting situations, disease or nitrate leaching. In fields negatively affected by these constraints, actual yields will be lower than estimates provided here.

It is important to keep in mind that yield forecasts are not field specific and, instead, represent an estimate of average on-farm yield for a given location and surrounding area in absence of the yield-reducing factors mentioned here. Likewise, crop stages and forecasted yields will deviate from the ones reported here in fields with planting dates or hybrid maturities that differ markedly from those used as the basis for the forecasts. We will follow up with further forecasts in early August.

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A field of corn.