The Next Step In Planting Perfection?
Apr 19, 2012
Some of you are way ahead of me on this, but this spring it finally dawned on me that in many cases, planter performance is limited by the quality of seedbed preparation.
For example: a customer and I wrestled with a planter that refused to plant at a consistent depth. Some seeds were 1 1/2-inches deep. Others were 2 or more inches deep. This occurred in the same row, often only a few feet from each other. He was no-tilling into last year's soybean stubble. He had fall-applied anhydrous, and the anhydrous knife marks were significantly more mellow than the untilled bean stubble. He had applied anhydrous at a slight angle to the rows, and whenever a planter unit crossed the mellow soil of a knife mark, it planted seeds an inch deeper than in the untilled soil between knife marks.
Another customer had a similar situation in fall-chiseled corn ground, after it had been field cultivated one time. We noticed variations in seed depth, and also differences in the density of the seed furrow sidewalls. We traced those variations to the speed and setting of his field cultivator---his sweeps, and tines on the leveler, were worn. The sweeps were leaving ridges, and the leveler teeth were leaving an uneven seedbed. In some places the planter's disk openers were carving a slot in hard soil that the worn sweeps had "missed." In others, the seeds were being planted only a 1/2-inch deep because that row was running in a groove that the tined leveler couldn't fill.
The best "looking" seedbed I've seen this spring came from a vertical tillage tool operated at 7 to 8 mph. It was beautiful--level, with crop residue nicely blended into the soil. The top inch or so had excellent tilth, and I was really impressed--till I started digging for seeds. There was a hard-pan about 2 inches down, and many of the seeds were sitting in crisp furrows carved into that hardpan. They were nicely covered and firmed into place, but I'll be curious how their roots deal with the hard walls of those seed furrows.
Those three situations impressed on me that even though we're getting pretty darned good at metering seed with fabled "picket fence" perfection, we've still got a lot to learn about getting those perfectly spaced seeds to sprout and emerge into a picket fence stand. Just because we put every seed 2 inches deep, spaced exactly 6 1/2 inches apart with the planter doesn't mean we'll have a picket fence stand when the corn is knee high. I think we're going to have to pay more attention to seedbed preparation if we want to take full advantage of the planting potential offered by modern planters.