By Tom Bechman and John Vogel
We'd like to say: "It ain't so!" But bigger planters need more end rows to turn on. If not managed well, they – or any size of planter – can hurt field corn yields. The good news is that you can do something to prevent or mitigate those losses.
Based on a 2013 farm field study by Farm Progress in Indiana, turning on those end rows with a big planter can cost nearly $30 an acre. Bigger planters mean more end rows, and more end rows mean a higher percentage of acres tied up in areas that get extra traffic, may get overplanted, may get plants driven down and where weed control may be less than optimum.
Doing the math
The length of the end rows was 80 rods or 1,320 feet on the 60-acre field. The farmer planted 32 end rows – two passes with a 16-row planter. On 60 acres of this field, that's about 4.9 acre. It's 8% of the field impacted by thinner stands, compacted soil and six to eight rows that were overpopulated due to planter overlap.
Now to the hardest numbers: Without the end rows, the field yielded 190 bushels an acre. The end rows yielded only 120 bushels an acre. The end rows dragged total field yield down to 183 bushels per acre. That's a 7-bushel-per-acre loss. Even at $4.25 a bushel, that's about $30 an acre.
Your remedies
American Agriculturist has published several articles during the last couple years about technologies and practices to reduce end-row losses. Here are a few of those suggestions:
•Use row shutoffs: Row shutoffs on planters can avoid end row overlap. Payback may be quicker than you think.
•Minimize end rows: Bigger planters do need bigger turn rows, but don't plant more than you need. Sometimes, end rows can be put to conservation uses.
•Avoid extra tillage: End rows soils don't need to be 'bug dust'. Don't till more than necessary.
•Clean up weeds: If a weed problem emerges on end rows, clean it up early-on with postemergence herbicides.