During the month of March, Mississippi farmers planted a lot of soybean fields — the most ever for March in our state. As of April 1 we had close to 100,000 acres planted.

The earliest planted acreage I know of went in the ground on March 8 and emerged March 22-23.

Although many are skeptical, I have no doubt planting early is the right decision. As I write this (April 2), the hill area of Mississippi has yet to dry up, and many farmers there are second-guessing the early planting concept.

Based on our experience of the last 10 years, however, early planting is not the answer to all our problems, but it is a significant and important option.

If I err, I want to err on the early side. I will take all the curve balls Mother Nature throws me early versus those that come later in the season.

Although we do not talk about this because it is somewhat confusing, the temperature at which soybeans will begin the germination process is slightly lower than for corn. But due to the greater vulnerability of soybeans to emergence problems, soil temperatures should be approaching or above 50 degrees F before planting.

Grass crops have a unique advantage over broadleaf crops because their growing point is not exposed initially. Soybean seedlings have a surprising ability to withstand freezing temperatures for relatively short periods.

Research in growth chambers at the University of Minnesota found that soybean seedlings in the two-leaf stage exposed to temperatures ranging from 25 to 30 degrees F for two hours experienced no major leaf injury. Longer periods at these temperatures killed upper leaves but not all axillary buds and regrowth occurred. Axillary buds are found from the terminal all the way down the plant to the cotyledons.

If the uppermost branches are injured (by cold weather), they may serve as protection to the lower nodes. The uppermost node not affected will become the new dominant terminal. Look at the effect of deer feeding. If a deer breaks the top out of a soybean plant, the next node down, all the way down to the cotyledons, have the potential to establish a new terminal. However, if the plant is broken off below the cotyledons, no new growth will take place. This new growing point is located in the leaf axil and is called an axillary bud.

You can see how resilient the soybean plant is.

Planting early to increase yields should be the goal of all soybean producers. Many of the concerns about early planting, but can be minimized through the following steps:

  1. Prior to May 1, plant for a rain. Many disagree with this suggestion, but it is a way to minimize stand problems. In late March through late April, we are going to get a rain (most of the time). In addition, rains during this time frame are often heavy, which can wreak havoc on emerging soybeans. Shallow planting will help plant emergence.

  2. Moisture loss is not as great this time of the year. Seed can lay there a long time before emerging. Soil temperatures warm faster at shallower depths and this aids in more rapid emergence.

  3. Minimize field preparation in the spring. Everything you do from harvest to planting should be centered around earliness. Think early.

    Stale seedbeds, no-till, and early burndowns all are options that should be used to the fullest. Check fields to determine what winter vegetation is present. If you have not put out a burndown by now (unless fields are clean) you have missed a valuable opportunity. Winter vegetation can keep fields colder and wetter longer or in a dry spring pump a lot of precious moisture out of the ground.

    The need for burndowns has varied tremendously this year. Use has ranged from a full-blown program to a “plant and wait” approach. In many fields where Roundup Ready soybeans were going to be planted we added Goal to the mixture, hoping for some residual control. The tank mix looks great (several other options are also available) and has offered broader spectrum control and faster activity versus a Roundup-alone program. My goal is to get enough residual activity to make only one postemergence application in some fields.

  4. Use the proper seed treatment.

  5. Calibrate planters each year. Check seeding rates when changing varieties. Base seeding rates on seed per foot of row, not pounds per acre. Do not overplant. Since the 2000 growing season was extremely dry, seed size may be quite small this year, and there might be variations in seed quality. It is imperative that you properly calibrate planters.

For those of you planting early, keep an eye on weed emergence. Early planting can offer you a real advantage as far as weed control goes, but it requires a less-than-conventional approach. Watch weed pressure, keep track of when emergence occurs and control weeds for the first four to five weeks after emergence of the crop. You will find that with early planting, early-emerged weeds often do not act normally.

Time your postemergence spraying to avoid competition but think about it coinciding with the crop canopying if possible.

Several farmers have asked me about planting Group Vs early. Group IVs should go in first, but we know the downside to planting Vs early is shorter plants. Narrow rows systems are preferred. If you are in wide rows, full canopy may not be achieved.

Dryland acreage deserves more attention than irrigated fields, but by planting irrigated Vs early you will probably avoid late-season worm pressure and possibly eliminate the need for some irrigations.

For those of you who have planted, we feel good about your decision. For those who have not yet tried the early planting concept, keep in mind this system is not the answer to all our problems, but it is a start.

What we used to do was not wrong, it was just what we knew to do at that time. A shift in maturity groups has taken place, thus the opportunity and need to shift planting dates has occurred.

If we can be of any assistance, do not hesitate to contact your county Extension office or local dealer. They will be happy to get in touch with us. In the next week or so, I will try to give you an update on some of these early beans scattered around the state.


Alan Blaine is the Mississippi Extension soybean specialist.
e-mail: ablaine@pss.msstate.edu