Who here has been out to their Cornfield with a spade or shovel in the last seven days? More importantly, who has dug up a few plants to see what’s going on with their rooting up to this point? As we have progressed through this season so far, we have seen many challenges, unfortunately, for every challenge, there is probably another one we don’t see.
Our corn has been through a lot this year, and it’s not even July yet. We have caused some of it, and we can blame Mother Nature for the rest. At the end of the day, the specifics of what has happened is pretty important, as it tells the story of the year, and helps us determine things we need to take action to prevent in the future vs. a non-manageable event. But I digress, because right now, what matters most is what is going on in your corn field. Sidewall compaction, hatchet roots, wet soil, dry soil, and disease has got us to where we are today. And guess what; where we are today isn’t that much different than other years. As I go back and look at last year’s root development on June 21, I see most fields had root activity at about 12 inches. As I look at AquaSystems now, I see that most of our corn is showing root activity at that same 12 inches. I know some of you are going to challenge this and say that seems unlikely after the spring we had, so I went back and looked at 2013 and 2014 as well, and on this same Madison County field, it was around the 20th-23rd that we started seeing root activity at 12 inches.
So history says the corn is behaving in a consistent manner with other years as far as where the roots are active, but I want us all to consider something here. Rooting depth, and active roots are two different things. With the absence of a compaction layer, our corn often roots down more than what it actively shows. That is to say, the true root depth of the corn, and how much of the corn’s roots are active are two different things. Corn is like me; it’s lazy. It’s never going to expend more energy to get something than it has to. If corn can find adequate moisture 8” below the soil, then that is what it is going to pull from. If it has to pull moisture from 20” down, it is going to have to expend more energy to get it. So just because a plant has roots, doesn’t mean they are actively used.
On the other hand, it has been hot. Like what I remember when I was a kid hot. When it’s hot, our daily use of water in ET is higher (ET – Evapo-Transpiration, one of those abbreviations I talked about last week). So that means there have been times our plants have shown stress, and you wanted to/or did start your pivots. We don’t want our corn to have a bad day after all. But our plants are going to add root volume as needed. Abundant moisture = less root growth; drier conditions = more root growth, drought = no root growth.
So on to the point, which is just like everything else in farming, balancing your roots development is a constantly evolving and changing paradigm. Water too often to avoid all stress, and you end up with a lot of shallow roots late in the season, and a plant that doesn’t finish strong. Stress it too much now, and you eliminate yield potential you never get back. Therefore, it would seem rather intuitive to eliminate stress and play with what you have later. But if you need to manage inches of water or your costs, that’s not feasible.
The moral of the story is this; plants will tell you what is going on if you listen. The above ground portion is easy. The below ground portion is not. We have to dig plants to see where we can potentially get moisture from, and watch our moisture probes to see where our levels are at. Balancing available water, and the stress we put on our roots at different depths is all part of the game. Each part of our puzzle has an image, but it’s when we put the pieces together that we can see the picture.