There are reams of data, much of it produced here in Indiana, that says even spacing for corn can produce better yields in stands are evenly spaced. Several agronomists preach the picket fence theory – if stands are spaced unevenly, yield can suffer. That's because some plants will have a neighbor that's too close and it may be treated as a weed.
Paul Jasa is an Extension ag engineer who has worked with tillage systems and planting systems for three decades. He stopped by Mike Starkey's planter clinic in Brownsburg recently to give his views on what it takes to get good stands and good yields in no-till, cover crops or any system. His opening statement surprised some people in the audience.
"Picket fence stands are not the most important thing to getting good stand establishment and top yield," he says. "It's even emergence of the corn plants – all coming up over a short time period – that is key to preserving yield potential."
Jasa is not saying drive fast, be sloppy, and don't worry about plant spacing. Instead, he's emphasizing the point that doing what you can to get seeds placed at the same depth in the soil so they will emerge uniformly is extremely important.
That starts with residue management in the fall, he notes. If you had a chaff spreader on your combine and spread the chaff evenly across the combine width, so that soil conditions will be the same no matter where the seed is planted, then you've gone a long way toward setting yourself up for good, uniform emergence in the spring, he says.
Jasa has taken the chopper off his combine. He says when you're first starting into reduced residue farming, a chopper opens the residue and lets some break down. After you've been in it for years and have healthy soils with lots of microbes, you don't want it to break down as fast, so you don't need the residue split apart.