It seems like just yesterday that I was fighting icy roads as I left the annual Mississippi Seedmen's meeting in Tunica, Miss. Less than three weeks following this ice storm, planters were running across the Delta.
It is amazing how fast things changed, but year-in year-out, planting early will be to your advantage. A small amount of planting began in early March, but it really picked up by March 9.
This is early, but over the last five years we have had a sizeable acreage planted from mid-March through early April. Some of these growers were concerned (as expected) initially, but all plantings survived. As a matter of fact, these same producers have told me repeatedly that their highest-yielding soybeans in the last few years have been those planted the earliest.
A frost is not the major concern, but temperatures low enough to allow a late freeze is another issue. The Mississippi Delta has an advantage over the hill area of the state because of wind movement. Larger fields do not break up wind movement and this prevents temperatures from reaching as low at ground level as they do where winds are slowed.
All in all, I feel we are pushing the envelope on planting dates. Although we have been successful, at some point we will get hit on some acreage. A late freeze in mid-April would prove to be detrimental to a portion of the crop but not the entire crop. Considering the higher yields associated with earlier plantings and the fact that the entire crop would not be affected, the risk is not too great. Yield increases for many growers in the last five years have been high enough to offset any risk.
A lot of interest has been generated regarding twin-row plantings in the last couple of years. This system will be beneficial, especially for growers growing beans on wide rows. Yield data last season showed approximately an 8 percent increase in yield for twin rows compared to wide-row beans. Previous yield data showed a 5 percent to 10 percent increase in yield for beans grown in 30-inch or narrower rows, versus wide rows. This increase is approximately the same as that observed with twin rows.
Additional advantages may be observed based on a row versus flat and possibly uniform seed spacing. The increased use of wide beds with narrow rows probably will prove to be comparable to a row with twin rows. Uniform seed spacing might prove to be beneficial, but given a soybean plant's ability to compensate, I doubt it will be as positive a response as it is for corn, if at all.
I have received a lot of calls regarding seeding rates for twin rows. Regardless of your row configuration, determine seed per foot of row, not pounds per acre. You should plant a wide row at the rate of eight to 10 (not 12) seed per foot of row. Given today's seed costs, a 20 percent to 25 percent error can cost you as much as $5 to $8 per acre. This will add up over several acres.
A twin row should be planted at the same population as a wide row, just half per row. There is no need to bump it any higher. Soybeans have a tremendous capacity to compensate, and we are getting better emergence under early/cooler conditions than what we used to get when we planted in June under hotter conditions.
Check planters for accuracy. As you change varieties, recheck planters. Seed size may vary; always calibrate on the basis of seed per foot of row, regardless of seed size. Smaller seed allow you to plant more acres, which translates into lower costs.
I like twin rows, but I do think that narrow-row plantings will yield as well. I may be proven wrong; time will tell. New planters have a lot of advantages over older models. Accurate seed metering and optimum placement will be big pluses.
Many are interested in equidistant spacing. Many new planters can accomplish this objective, but the benefit will probably not be as significant as what has been observed in corn.
Alan Blaine is the Mississippi Extension soybean specialist. e-mail: firstname.lastname@example.org