Short-term weather forecast and considerations for tillage, corn emergence and planting delays

By: Angie Peltier, Extension educator, Dennis Todey; director of the Midwest USDA Climate Hub and Jeffrey Coulter, Extension corn agronomist

The following information was provided during the debut 2023 Strategic Farming: Field Notes session. Read further to learn more about this free program that takes place each Wednesday morning throughout the growing season.

Precipitation report

The USDA’s Midwest Climate Hub produces agriculture-specific climate information for an 8 state region, including Minnesota. The last 30 days have been drier than normal for the southern edge and western Minnesota, but the northeast quarter of Minnesota and extending down diagonally toward southwest Minnesota has been wetter than normal, with this area receiving between 120 and 150% of normal precipitation. These short-term conditions are a continuation of trends seen since October 2022, with the same regions of the state either accumulating above or below normal precipitation for the past 7 months AND the past month.

US Drought Monitor report

Some theorize that in some areas of the state, snow arrived last fall before soils had frozen and in other area soils may have thawed this spring before all of the snow melted. Regardless of the cause of thawed soils this spring, much of the snow that we received over the winter was able to infiltrate the soil, leading to much of the state having adequate or wet soils. According to the latest US Drought Monitor map (released on May 4, 2023), 52% of the state is normal with western Minnesota abnormally dry and a few of the southern border counties in a moderate drought.

Planting progress

Each Monday morning, the USDA National Agricultural Statistics Service releases a crop progress and condition report as of the preceding Sunday and nationwide maps of state-by-state total progress and progress since the following week are generated on Tuesdays. The report released on May 9 reporting on planting progress as of May 7 estimates that 38% of the corn acres in Minnesota have been planted, up from the 5% reported the previous week. Minnesota’s farmers are also making progress planting soybeans, with 13% of the crop planted, up from the 1% planted the previous week. Seven percent of spring wheat acres and 23% of sugarbeet acres have also been planted.

El Nino predicted – implications for summer weather

We are moving away from la Nina (when ocean temperatures in the Pacific Ocean along South America are cooler than average) conditions, and climatologists are projecting an 80% probability of el Nino (warmer than average Pacific Ocean temperatures along South America). El Nino years tend to have more moderate temperatures and a lower likelihood of drier conditions. On a positive note, cooler, more moderate temperatures during grain fill tends to be beneficial.

Near-term forecast

In the next 7 days, western Minnesota has a good chance of 1-2 inches of rain. This will slow planting progress, but forecasters expect the 3rd week of May until the end of the month to have a greater likelihood of drier and cooler than normal weather.

Considerations for corn emergence and delayed planting

It takes approximately 120 growing degrees day units for corn to emerge after planting. With the recent weather conditions, it should take 10 to 12 days after planting for corn to emerge. For those looking at the near-term forecast and the calendar days passing, there may be some worry about the optimal planting window for corn slipping away. However, we are still nearly two weeks away from when one would be advised to consider adjusting to an earlier maturing hybrid. After May 21, it is recommended that one consider shortening their hybrid maturity by 5 to 7 days when compared to full-season hybrids for their area (https://extension.umn.edu/corn-planting/considerations-late-planted-corn-minnesota).

Wait for fit soil conditions 

At the time of tillage or planting, soils should crumble at one inch below the depth of tillage and planting. Tilling fields when soil is too wet risks soil getting cloddy. Planting into cloddy soils often leads to uneven crop emergence, because clods allow air pockets to form around clods in soil, thereby reducing seed-to-soil contact. That is problematic because uniform emergence requires adequate and consistent seed-to-soil contact for all seeds so that seeds can rapidly imbibe enough water for germination. Uneven emergence reduces overall yield potential of a crop, as later emerging plants tend to be smaller and not as able to compete for limited sun, water, and nutrients.

Do you want to attend Field Notes next week? 

This program will run from 8:00-8:30 a.m. on Wednesdays through the 2023 growing season. Topics will be announced the week of the program and may include issues related to soil fertility, agronomics, pest management, equipment, and more.

Learn more and register

Can’t make the live session? No problem. The discussion-based series will be posted immediately following the webinar to your favorite podcast-streaming service to listen at your convenience. Listen here online.

Thanks to the Minnesota Soybean Research and Promotion Council and the Minnesota Corn Research and Promotion Council for their support of this program.