Corn Nutrient Deficiency from Sidewall Compaction

Chad Lee, Extension Professor and Agronomist, University of Kentucky

This corn field had numerous plants that were stunted with striped leaves. This field was adequate to high in soil test values and had proper pH. When we dug up some plants, we found that the majority of stunted plants suffered from sidewall compaction. Images of the field, the leaf symptoms and the compacted roots follow.

Field where most of the corn appeared yellow with striped leaves.

Looking Ahead: Expect to See Sidewall Compaction

Chad Lee and Carrie Knott, Extension Agronomists, University of Kentucky

Figure 1. Open seed furrow is a good indicator
of sidewall compaction.

The calendar says we are getting late on planting corn. While the soil conditions are probably more important than planting date, there will be intense pressure on producers to plant corn this week. That means that some fields will likely get planted too wet. Getting into a field too soon is completely understandable given the logistics of planting multiple fields and trying to "sneak in" a field between rains.

Corn Problems from Weather and other Factors

Chad Lee, Extension Agronomist, University of Kentucky

All spring we have been discussing deficiencies on corn plants and trying to determine if they are to blame on the weather or something else. Below are few fields with some images as examples.

Field 1: Healthy Corn, Adequate Nutrients, No Compaction

Field 1. Striping, but no compaction.

This corn in Field 1 is at V7 and has striping that might indicate a deficiency in manganese or sulfur.  There is no compaction and all nutrients should be in adequate supply, based on a recent soil test and fertilizers applied. A sidedress application of nitrogen occurred about about a week before these photos. So, a gentle rain and some sun will make this corn "jump" and the striping disappear. I refer to this kind of symptom as a "transient deficiency" meaning that the symptoms are related more to weather than anything else.

Delayed Corn Planting Doesn't Mean Lower Yields

Chad Lee, Extension Agronomist, University of Kentucky

Corn planting is slower across the majority of Kentucky this year. Again, we are faced with the temptation to get into fields as soon as possible. Simply having some corn in the fields will help us sleep better at night. But if we get into the fields too early we may have nightmares later in the season. Getting into a field one day too early often leads to sidewall compaction, which can severely hurt yields.

Resist Mudding in Corn... or at Least Try to Minimize Problems when you Do

Chad Lee, Extension Agronomist, University of Kentucky

Visible slot from planting.
Undamaged corn in the field is at tassel/silking,
but the plants with sidewall compaction
are not close to tassel.

The wet weather and calendar increase the urge to get back into the fields earlier. Getting into the field "one day too soon" can result in sidewall compaction and/or surface compaction that will put the corn crop further behind all season.

Below are some images that serve as reminders of what happens when fields are planted too wet.

More Corn and Soybean Challenges in Fields

Chad Lee, Extension Agronomist, University of Kentucky

The images from field problems in Kentucky has been updated. Because the file was getting very large, you can access only the May 2012, June 2012 or the full version which includes wheat. If you access the full version, just be aware that it is 23.5 MB... and growing.

The most common symptom in corn is potassium (K) deficiency. In most cases, the K deficiency is the result of root restriction. Most of the root restriction is from compaction, whether it be sidewall or sub-surface. Areas of Kentucky had ample rain during corn planting and getting sidewall compaction would have been very easy to do. The general lack of rain now adds to the problem.

The compaction limits root growth, reducing the root interaction with nutrients. Water is needed for uptake of many nutrients, including compaction. The lack of water reduces the amount of K taken up by the plant. Either dry weather or compaction on their own can cause problem, but having both together causes even more troubles.

Sidewall Compaction Early Hurts Yields Late

Chad Lee, Extension Agronomist, University of Kentucky

Earlier in the season, we tried to warn about planting too early and the risks of sidewall compaction. Nick Roy, County Ag Agent in Adair County did some yield checks in a field with and without sidewall compaction. Below are his reports.

All yield checks are from the same field.

Area 1) yield check: 161 bu/acre: no compaction found, good plant color:

Area 2) yield check: 130 bu/acre: some signs of compaction, fair plant color, occassional furrow open a litle

Sidewall Compaction in Corn

Chad Lee, Extension Agronomist, University of Kentucky

  Earlier, we posted about sidewall compaction with the understanding that farmers had to plant when they could plant and in some cases, this meant planting into fields that were a little too wet. Yesterday I visited a field where the farmer was concerned because the corn was "yellow and dying". The county agent and I visited the field at the perfect time because a rain from the night before had kept the soils wet and improved the appearance of the corn.



Corn in a compacted seed furrow. The slit of the furrow is still open. The oldest leaf has brown along the margin and yellow moving toward the midrib of the leaf, which is typical K deficiency symptoms.  



Do as I Say not as I Do ... Challenges with Planting

Chad Lee, Grain Crops Extension Agronomist, University of Kentucky

Often this spring, I have warned farmers not to plant one day too early to avoid "mudding in" the corn or soybeans. When we plant just one day too soon, we increase the chances of getting sidewall compaction and run a higher risk of keeping the roots bound within the furrow. Roots trapped in the furrow can lead to some real problems later in the growing season. However, yesterday, I disregarded all of that caution and mudded in soybeans.

Avoiding Sidewall Compacting During Late Corn Planting

Lloyd Murdock, Extension Soils Specialist
Plant and Soil Sciences, University of Kentucky

Sidewall compaction can result from planting a crop when the soil is a little too wet. This damaging effect can be even greater on soils with a relatively high clay content at the surface. It occurs when the double disc opener leaves the side wall of the planting furrow smooth and compacted (slick as opposed to shattered) as it pushes the soil aside. The trailing press wheel then increases the compaction with its downward force. If the soil stays very moist or wet, the roots may be able to penetrate the compacted mud at the sidewall and expand further into the soil. However, if the weather turns dry after planting, the sidewalls then harden, and roots are not able to push through since there are no pores or cracks. This causes the roots to grow within the planting furrow, along the direction of the row. Although plants may look normal at emergence, they will begin to show nutrient and drought stress after the corn is several inches high. This problem may be more common in no-tillage because no-tillage soils have better structure, and it is easier to traffic them in a wetter condition. The old adage of "waiting on no-till" is a good one. Sidewall compaction can also occur with conventional tillage. If you can mold the soil into a ball in your hand and the soil ball will not easily crumble apart, it is too wet to plant.