Take a close look at the picture with this article. The main rows of the field are to the right. The end rows are to the left. Note there are a few stalks of corn one row and in some cases two rows into the end rows. That's it – there are no more stalks because no more corn was planted there.
This farmer spent the money to equip his 24-row planter with clutches to achieve automatic shut-off. He calculates in seed savings alone on approximately 3,500 acres of crops, he can pay for the feature in one season.
Sound far-fetched? It's not. A University of Kentucky ag economist prepared a pay-off analysis in 2013 for Indiana Prairie Farmer and found that along with auto shut-off on sprayer booms, these technologies pay for themselves as quickly or quicker than any other technologies out there.
Why? Seed is approximately $3 per 1,000 seeds. That's if you buy seed for $240 per bag. If the shut-offs save you 3% in seed, that's $9 per unit, or 80,000 kernels, saved. You would save more than $5,000 on those 1,750 acres. That doesn't account for extra savings on point rows or fields with obstacles where pairs of rows shut off to avoid overplanting as you go around the obstacle.
That's in a rectangular field. Some objected to the article a year ago because they claimed that in rectangular fields they wouldn't save money. If you walk a normal field and the corn from the long rows goes six to eight rows into the end rows, you're wasting more seed than you think.
It also doesn't account for reduced yield on those thicker rows. Most hybrids aren't ready for 64,000 kernels per acre, and yields may actually drop.
Some also believe 3% is conservative, and that 4% or even 5% is a better estimate. Do your own math and compare it to the cost of converting your own planter. If you farm fewer acres, it may take longer. On the other hand if you run a smaller planter, that cuts the cost outlay that must be paid back.