Vertical tillage sounds simple enough. Cur residue and disturb the soil vertically, not horizontally. Don't engage in aggressive horizontal soil movement common to the disk. Yet there seems to be a wide range of opinions growing out there about what vertical tillage really is.
Talk to a farmer who wants stalks cut up, and he doesn't mind a little horizontal movement. Talk to a true no-tiller, and he contends that at least one of the main tools on the market is too aggressive to actually be called a vertical tillage tool. Yet farmers who try it like it, for the most part, especially if it's set up correctly.
To a true no-tiller, it might even be an Aer-way tool or just a fancy drag that moves stalks and loosens the soil. To someone more use to tilling rather than no-tilling, such a tool likely won't move enough soil and residue.
Some people contend that while they're best used in the f all to break down residue and let soil decomposition start faster, they can also be used in the spring. They're a ' do it before it's not dry enough to plant' tool that 'airs out the ground.' That was the faulty argument made for the disk in the old days. The trouble was that the disk aired it our too much, bringing up wet soil from several inches below the surface. But will a trip with a vertical tillage tool into stalk ground a day before you would plant it actually help it dry out? Or does it add soil compaction because you're trafficking the field perhaps before you should?
These are all questions, and there are more questions than answers right now. The question about whether going out with the tool to dry to dry the ground out before planting brought puzzled looks and no answers from farmers a the recent Riple4y County soil and water conservation-sponsored annual no-till farmer's forum. No one had a good answer.
Indianan Prairie Farmer did a little testing of our own recently. The issue we wanted to answer was how much less residue cover there was after running a vertical tillage tool rather than jus no-tilling the field.
Using the knotted rope method and measuring residue touching the knots at 6-inch intervals, the difference was barely over 10%m with 81% residue coverage left after planting into corn stalks, and around 70% after planting into vertical tillage. The difference was in the length of the prices of residue. Obviously, they were longer where drilled and shorter where sliced by the rolling coulter pulled at 9.4 miles per hour.
So is that slightly less residue cover a disadvantage for soil erosion? Or is it an advantage because the residue in smaller pieces will break down faster, and release nutrients back to the soil sooner?
These are just some of the issues which make vertical tillage still somewhat of an unknown. Farmers will vote with their pocketbook the tools aren't cheapo.