Out in the field, the old saying goes: “A tiller bites in by its own weight; depth lives on the gauge wheel.” That is only half true. Follow it too literally on a hard field and the tiller just skims the surface while you sit there wondering what went wrong. The hydraulic lift on the back of your tractor gives you two genuinely different ways to handle depth — float and forced, often called strong-pressure — and picking the wrong one changes the finish of your field, your fuel use, and even your tire grip.

Here is the short version you can use right now:

• Loose soil, uneven ground, tiller with a gauge wheel → run it in float.
• Hard or crusted soil, poor penetration, depth all over the place → switch to forced and use the power-down.

Both lines make sense once you know why, so let’s unpack them.

Float and forced differ in one thing: whether the lift arms actively push down

In float, you push the control lever all the way to the float position and the hydraulic system lets go. The lift arms swing freely, and the tiller basically rides on its own weight plus the gauge wheel to hold depth. High spots and low spots, it follows the contour — that is what people mean by ground-following tillage. The upside is an even depth on bumpy fields, without you forcing extra depth into any one spot. The downside: there is no downward push. On soil that is even a little firm, the weight is not enough and depth starts to drift.

Forced mode is different. The hydraulic cylinder actively pushes the implement down (the power-down function), so the tiller bites in fast and hard — hard enough that it can actually lift the rear wheels of the tractor, which is the quickest way to tell a real forced system from a fake. Once it is at the depth you want, you pull the lever back to neutral and the tiller stays locked there. The catch: it does not follow the ground. If a tire rolls into a hollow, the tiller gets shoved down; roll up over a mound and it gets yanked up, so you end up with a washboard surface.

How to actually choose: a trial-and-error routine

No single answer covers every field, because fields change. Most experienced operators work it like this:

First, run one pass in float. If it bites in well, depth is steady, and it is deep enough, stop there. Float is the easiest on the tractor and the most fuel-friendly, so use it whenever it does the job.

Second, if something is off — the tiller will not dig in, or it is clearly running deep one minute and shallow the next — switch to forced. Power it down to the depth you need, and the moment it gets there, pull the lever back to neutral. That gets you penetration without riding the down-pressure all the way across the field.

Third, on genuinely hard ground (or when you want a field finished in one good pass), try the two-pass trick: open the surface with float on the first pass, then finish with forced on the second to hold a set depth. Once the first pass has loosened the soil, the forced pass is not fighting virgin ground, so the depth holds much better. Lots of old hands run it exactly this way.

The traps people fall into

Do not treat forced as a fix-all. It solves poor penetration, but not every depth problem. If the ground is dry and iron-hard, or the blades are worn blunt, the tiller will not reach depth no matter how hard you push — the down-pressure cannot make it bite. Check the soil and the blades before you blame the control mode.

Do not ride the down-pressure for the whole pass. The downward force borrows weight off the tractor’s rear wheels, which cuts grip — you get wheel spin, and in bad cases you lose traction altogether. Add any ground undulation and you will leave washboard. Push to depth, then back to neutral. Do not get lazy.

Do not ignore the gauge wheel and the stops. How well float works depends a lot on whether the gauge wheel is set right and the lift arms are free; how well forced holds a depth depends on whether the cylinder has a proper stop. And that float/forced selector switch (on some tractors it is a pin — sideways for forced, dropped into the slot for float) — make sure it is not flipped the wrong way year-round.

Do not assume your tractor even has forced. Small wheeled tractors and crawlers mostly run float only; forced usually comes with separate or forced-lift hydraulics. Before you buy, or before you blame the setting, check which hydraulic control form your tractor actually has.

Questions operators actually ask

Q: On soft soil, won’t the tiller sink deeper and deeper in float?

A: Soft ground is where float shines. With the gauge wheel it follows the contour and generally will not bury itself. The thing to avoid is forced, which just shoves the implement down into the mud.

Q: Can forced hold a really deep setting?

A: It can hold it — provided it can push that deep. Whether depth actually reaches the mark depends on soil hardness and blade condition; forced just supplies the bite-in force.

Q: Should I switch back to float mid-field?

A: Depends on the ground. On flat, hard ground, run forced locked to depth all day. On fields with slopes and hollows, drop back to float and let the implement follow the terrain — less grief than fighting it with forced.

Q: How do I tell if my tractor has true forced?

A: Easiest check: power the lever down and watch the rear wheels. If they lift, you have real down-pressure. If nothing moves, you are on float only.

Float or forced is not written in the owner’s manual — it is written in your field. Start with float, switch to forced only to bite in and then back to neutral at depth, and use the two-pass routine on hard ground. That logic will serve you far better than “always float” or “always forced.”