My phone rang and it was a farmer from south-central Indiana. He observed something so strange harvesting this fall that he wanted to share it. You will see more about it in more detail later this winter in Indiana Prairie Farmer. Here's the brief version.
Anthony Rust, Seymour, harvested a field of soybeans in "clay" ground in Jennings County that was in a corn-soybean rotation. Two acres at the back of the field – the lowest, wettest part of the field – had just been bought and added to the field this year. It had not been in soybeans for roughly 15 years.
The entire field looked good, Rust said. But when he got into it, the soybeans on the bulk of the field yielded below average. Soybean seed size was small. He and the people who advise him determined that it was sudden death syndrome that affected the field.
On the two acres in the back, the yield was almost double, Rust says. He has a combine yield map to prove it. And he says that once he got into that part of the field it was noticeable.
He realizes it wasn't replicated and it's an observation, but it left a searing picture in his mind. He questions the wisdom of too many years of soybeans in a field. He wonders if it contributes to build-up of diseases that attack soybeans.
Agronomists usually concur that rotation vs. a monoculture is typically the best bet. One advantage is that it doesn't allow pests that affect one crop to build up.
You may be tempted to go back on beans with beans this year to save on input costs. If you saw what Rust saw, you might think again. You might at least make sure if you have to go beans after beans once, you don't come back with beans in the same field three years in a row.