Stip-Till Series: Timing, Tools and Depth
Part 2 of 3
Should I use coulters or shanks?
First questions to ask when choosing equipment is: what are my soil characteristics and what is my goal with strip-till? The best approach might also vary between fields in your operation. Shanks use to be the more popular option but more recently, coulters are pulling ahead.
- Rocky and/or light textured soil? Coulters are likely your best option, otherwise, be prepared to pick stones.
-Heavier texture soil? A shank is more aggressive and may be a better choice.
If you're looking to make a nice berm or you are trying to break up compaction, a shank is probably going to help you achieve this better. It also lends itself better to banding fertilizer.
If you have heavier residue, coulters do a better job at cutting through it, they are also less likely to degrade soil structure in the strip. As for fertilizer applications, if you want to blend fertilizer in the strip or bookend two bands on either side of your strips, coulters can do this for you.
Of course using both coulters and shanks is an option, and some farmers will alternate depending on the field and the timing of their tillage. Most rigs also have row cleaners and firming baskets to help create a better seed bed and planting conditions.
How deep should I go?
Tillage depth in a strip-till system is usually within 4-8 inches. Shanks are often used for the deeper end of this range, while coulters tend to be used for more shallow tillage. On a heavier soil, you'll want to go deeper than a lighter or a rocky soil. This works out well, because, as I mentioned earlier, on a heavy soil you will more likely want to use shanks and vice versa. If you want deeper tillage when using a coulter system and don't want shanks, you can add cogs to increase the depth.
Should I do fall or spring tillage?
Often it comes down to when do I have most time? Spring is usually very busy and late summer/fall may be when you have the most time on your hands. Particularly, if you stip-till wheat stubble ahead of corn. You could get it done when the soil is dry in early August.
If you need to break up compactions in heavy textured soil and clods need time to settle before planting, a fall pass would be better, but if you have a light textured soil, spring would be best. If you are concerned about fall tillage and stale seed beds, according to many strip-till farmers, this is not and issue.
If you deal with erosion problems and have complex topography or significant slopes on your fields, you might want as much root mass in the ground to keep soil in place over the winter, so spring tillage would make more sense for you. If you struggle with cold wet soils in the spring, this could also help warm and dry the soil so it's ready for planting sooner. Stip-Tilled soils, when compared to to conventional, have better equipment carrying ability, so theoretically, you could make your tillage pass earlier, and get planting started before your neighbour.
If you decide your tillage timing simply based on what equipment you have, generally, shanks are better for fall and coulters are better for spring tillage, and again, of course, there are people who do a fall and a spring pass. This might be out of habit from conventional tillage days or to deal with heavier residue.
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March 26, 2021