Would a “dry June for the roots to go down” or a slow soaking inch once a week this month be better in 2024?
By: Mike Toohill, AgVenture WSC
Bloomington, IL
The case for the “dry June for the roots to go down”:
That was one of my grandpa Graf's keys to high corn yields. He liked the roots to have to search for moisture and nutrients in June in order to toughen up the plant prior to pollination. A deep root system also bodes well for post pollination moisture stress. A dry June also limits nitrogen loss (another key component to high corn yields). In looking back to 2022 and 2023 (in Illinois anyway), the very dry Junes followed by timely late June and ample July rains did allow for much higher corn yields that few in the industry (including me) expected.
The case for a slow soaking inch once a week all June:
Although the first 30% or so of the Midwest corn crop went in with good soil conditions, a high % of the last 70% or so was tilled and/or planted into marginal conditions (especially the first day or so of our limited windows). Thus, I expect widespread soil compaction issues if we get into the dry June scenario. Why? Hot dry soils with a compaction layer limits root exploration. But if we can catch occasional soil softening rains followed by 4 or 5 days of drying soil with increasing oxygen levels, it allows the corn roots a much better opportunity to penetrate compaction layers.
More support for the inch a week: a high % of the Midwest corn crop was planted mid-May or later. Agronomists often comment about “bonus/catch up” GDDs for later planted corn that can occur with maximum temperatures above 86 (the upper limit on the corn GDD calculation). But for later planted corn to have a chance for RM catch up, it has to have adequate root accessible moisture to continue growing during the hottest part of the day. Late planted corn and a very dry June (especially with some compaction underneath) will increase stress response when it’s the hottest. The Bottom line, if it’s rolling it’s not growing ..
My verdict on the best June weather scenario:
Based on current conditions, I’m going with slow soaking inch once a week. I’ll also take lots of sun and average to above average temperatures after each rain. The worst June weather scenario for 2024 Midwest corn crop: Hot and very wet. In this scenario, the roots will stay shallow where the limited oxygen supply will be the highest (although still far from adequate). Root accessibility to nutrients will be compromised and slow growing yellow (sulfur and/or nitrogen deficient) corn will be common. Saturated soils also limit the roots soil compaction penetration “want to”. Denitrification also increases with consecutive days of saturation and hotter soil temperature.
The current June outlook:
In looking at the maps, a dry June in the Midwest doesn’t look likely at this time. Hopefully the green stripe of above normal probabilities for precipitation doesn’t verify and we can end up with near normal precipitation. The Midwest temperature outlook for June didn’t have a bias when the maps were issued.
Related Articles
