Suppose you've got two planters and 1,000 acres left to plant tomorrow, May 25. Should you plant corn with both, or run corn with one and soybeans with the other? While the answer may seem obvious- run corn with both to avoid further yield delay, data compiled by Syngenta through research projects at various locations indicates that the answer may not be as obvious as you think.
Soybean yield slips for every week beans remain in the bulk storage unit this time of year too. That might not be a big surprise, but the amount of slip might be. In the central Corn Belt, Syngenta agronomists calculate that based upon their data, soybean yield drops on average 2.5 bushels per acre per week of delay.
Let's say corn yield drops the same amount. Some sources would indicate they drop more, and we'll deal with that later. At 1.5 bushels per day, corn would drop more than 10 bushels per acre in one week. For this first example, say it's just 2.5 bushels per week.
If you could plant 150 acres per day with that second planter, and you don't plant corn, you give up 2,675 bushels in yield potential for another week's delay at $7 per bushel, that's $18,725.
Now suppose you plant the corn and gain that $18,725 back. But you miss out on planting 1,050 soybean acres. Actually, it could be more if you're applying starter on corn and not soybeans, meaning you don't have to stop as often. But let's stick with 150 acres per day. By not planting those 1,050 acres for another week, Syngenta data says you forfeit 2,675 bushels of soybean yield potential that you can't ever get back. At $12 per bushel, that's $31,500, far more than the $18,725 you sacrificed for corn.
Syngenta's data for soybean yield loss is based upon more than 4,000 grower strip trials for the period form 2007 through 2009. While the study was conducted at several points north and south in the Corn Belt, they discovered that the average of 2.5 bushels per week yield loss remained constant.
If the more aggressive corn estimates are true and you give up 10 bushels per week of delay that late in the season, the numbers change dramatically. By not panting 1,050 acres of corn at $7 per bushel, you would give up $73,500, more than double losses from not planting soybeans.
These calculations show you've got some heady decisions to make if you have to choose. The bottom line is how much yield loss you would expect from each crop. The Syngenta information makes it clear that it's worth doing the calculations. Letting those future soybean acres sit idle for another week are not free, either.