Should you plant corn or soybeans first? The most hated answer is, “It depends.” where is your farm? What will the weather be like? How big is your planter? Do you have two planters?
Let’s start with two simple questions: What is the best planting date for corn? For soybeans? Both crops respond to early planting. Long-term data proves this.
What the data says
Here is an example. “He has been conducting comparative studies of soybean planting dates in our Practical Farm Research Program for 26 years,” says Steve Gauck, regional agronomy manager at Bex. “From April 1st to May 15th there is virtually no difference, and April 16th to 30th is the absolute highest yielding period. Yields decline in June.”
A similar trend is observed in corn. Based on 23 years of multi-location data, yields as a percent of average yield for various planting periods are as follows:
Similar to soybeans, April 16 to 30 is the best-performing planting date range for corn.
new approach
The Battle for the Belt challenge began in Ohio in 2023. Osler Ortez, an extension corn specialist at The Ohio State University, and Laura Lindsey, an extension soybean specialist at OSU, wanted to decide whether to plant corn or soybeans first. I am.
The challenge includes five planting date ranges, three locations, four hybrids ranging from 100 days to 115 days of maturity, and four seeding rates from 100,000 to 210,000 soybeans per acre. It is located in Wood County in northwestern Ohio, Clark County in west-central Ohio, and Wayne County in northeastern Ohio.
“[2023] “This has been a year of extreme weather, and most of these days have been extreme,” Lindsey said.
Ortez added: “Weather effects are one of the variables that must be considered when deciding which crop to plant first. It also affects weed, pest and disease management, crop fertility management, commodity prices, economics, etc. Please also consider.”
1st year results
Here are the results for 2023:
The best dates vary. Corn yields were highest during the first three planting dates in northwest Ohio. Yields of corn planted after May 11 declined sharply. The most suitable planting date for soybeans was his April, and May and his June plantings resulted in a gradual decrease in yield.
In Northeast Ohio, May 11 was the best day for both crops. Ortez said previously planted corn was affected by the cool, wet start. For soybeans, Lindsey added that a combination of weather, disease and insects resulted in a final population of less than 40,000 for the April planting.
Conditions and Calendar. “Believe it or not, May 25th was the best time to plant corn in west-central Ohio,” Ortez said. “It was wet early on. Then it got dry. Roots didn’t develop well. Floppy corn was developed. Corn planted on May 25th suffered no damage. We’re not recommending planting corn on May 25th. We’re just reporting what we see in one location per year.”
Ortez points out that this goes against the recommendation to plant corn in late April or early May. “The results tell us to compare field conditions to calendar dates,” he says.
“Here, soybean yields were not affected by bad weather,” Lindsey points out. “The first planting date in mid-April averaged 91 bushels per acre.”
Hybrid difference. In trials in northwest Ohio, 115-day all-season hybrids planted early performed best. In Northeast Ohio, the 107-day and 115-day hybrids performed best on May 11th. The 107-day hybrid reached 275 bushels per acre planted May 25 in Midwest Ohio.
1 year’s worth of gleanings
Here are some takeaways from the first year of research:
Soybean yields have become more stable. Soybean yields were more consistent across planting dates, Ortez said. Corn yields were more variable and more influenced by the environment.
Soybean yields have decreased due to delayed planting. Soybean yield consistently decreased with later sowing dates. The only exception was northeastern Ohio, where extremely low plant populations affected yields of early planted soybeans.
Corn planting trends were less consistent. “In some cases it was OK to plant corn earlier, but in other cases it was better to plant it in May or even late May,” Ortez said.
There is still more to learn. Researchers report that the battle for the belt will continue in 2024 and 2025. Dig deeper into weather, weeds, insects, diseases, grain quality, and economic dynamics.
Are low temperatures coming?beans can accept it
Conventional logic once said that corn should be planted first because it can tolerate colder temperatures. Even five-leaf corn can recover from frost. If the soybeans freeze, the game is over.
Today, “common sense” has to be fine-tuned. It is true that soybean seedlings will not recover if they are frozen. But tests by seed companies and universities have demonstrated that much lower temperatures are needed to cause serious damage to soybeans than previously thought.
The March 2001 issue 2 Indiana Prairie Farmer cover story cites data from a joint study by Beck’s University and Purdue University. During his three stages of growth from emergence to the first three leaves, he was exposed to temperatures of 32, 29, and 26 degrees Fahrenheit for 30 minutes, 2 hours, and 4 hours in Purdue’s growth chamber.
Only the largest plants exposed to the coldest temperatures for the longest time showed damage. Kevin Kavanaugh, Vex’s director of research at the time, said, “We weren’t calm enough!”
In subsequent tests by Bex, it took six hours at 25 degrees to reduce a single-leaf stage soybean stand by 50%. Some plants survived even at 23 degrees. they can accept it.
