There is no standalone GPS-guided hay rake or tedder. The GPS lives on the tractor. What you actually buy for haymaking is tractor auto-steer that drives straighter, matched, lower-overlap passes across the mow-ted-rake-bale chain. It is a pass-consistency tool, not a hay-quality tool.
That distinction is the whole point of this guide, because it decides where your money goes. Spend it in the wrong place and you will own a very straight line to mediocre hay. Spend it in the right order and you will cut waste, tighten your windrows, and stop fighting the same strip twice at eleven at night.
No. The rake and the tedder are dumb towed implements. They have no brain, no receiver, and no idea where they are in the field. The intelligence sits on the tractor pulling them, in the form of a guidance display and either an assisted-steering kit or full auto-steer.
This matters because the marketing shorthand ("GPS-guided rake," "smart tedder," "section control hay tools") sends farmers shopping for the wrong box. You will not find a rake with a satellite antenna that magically forms perfect windrows. You will find tractor guidance systems that keep whatever you are towing on consistent, repeatable lines. Even the higher-end feature called implement guidance is a tractor-side function: extra GPS references steer the tractor so the trailing implement tracks the intended path. The implement still just follows.
Get this right in your own head first, and the rest of the buying decision gets simple. You are upgrading the tractor. The rake and tedder you already run are fine hardware for the job, and the guidance rides in front of them.
The honest, measurable win is that you stop wasting the pass. With manual steering, most operators leave a foot or two of overlap on every round to make sure they do not skip a strip. Guidance closes that gap. One haymaker running affordable guidance reported cutting overlap from one to two feet down to six inches or less, which he tied to roughly five percent better fuel efficiency and a couple hundred dollars saved over the season. Another operator got what used to take two to two and a half days of manual cutting done in one to one and a half days, mostly by adding night and low-visibility running. Those are single-operator, vendor-published accounts, so treat them as direction and magnitude rather than a promise. The mechanism behind them is not in dispute.
The bigger structural benefit is matched passes across the whole chain. Hay is a race against a narrow weather window. When the mower, tedder, rake, and baler all drive the same consistent lines, their working widths line up pass after pass instead of drifting into skips and double-covered lanes. A tired operator steering by feel at the end of a long day misses strips and re-covers others. Auto-steer takes the steering off the operator's plate so the eyes go where they are actually needed, watching for rocks, groundhog holes, and wet spots, while the crop dries on schedule.
Less fatigue is not a soft benefit here. It is the difference between quitting at dusk and finishing the field under lights while the forecast still holds.
It means auto-steer, and nothing more. This is the one place the keyword needs an honest answer.
Section control is a planter and sprayer technology. On a planter it shuts off individual row units over ground you have already seeded; on a sprayer it closes individual nozzles over already-sprayed passes. You physically cannot do that to a rake or a tedder. There are no sections to switch off. You cannot turn off half a rotary rake.
So when a haymaker talks about "section control" for hay, what they actually want is the outcome section control gives a sprayer: no double coverage. Auto-steer delivers exactly that by keeping every pass on its own line, which stops you from double-raking and double-tedding the same strip. Same benefit, different mechanism. If a listing tries to sell you a section-control rake, it is selling you a term that does not apply to the machine.
Towed implements drift, and that drift is where your windrow quality actually lives. On a side slope, the drag of the ground pulls a tow-behind rake or tedder downhill and increases its skew angle. On curves and headlands, the implement cuts inside or outside the tractor's line, leaving a missed strip on one side and a double-covered lane on the other. Your tractor can be dead on the A-B line while the rake behind it walks off into the next windrow.
Passive implement guidance fixes this by putting a GPS reference on the implement (or reading its position) and steering the tractor so the implement stays on the intended path, not just the tractor. On the raking side, steerable tandem hitches offset the rear rake left or right for single or double windrowing while transmitting the tractor's steering so the rake follows precisely instead of dragging wide on the turns.
This is the piece of "GPS haymaking" that most directly cleans up the windrow itself, which is why it is worth the add-on cost if your fields have contours, point rows, or side hills. On a flat, square field, a good operator loses very little to implement drift and this feature earns its keep more slowly. Buy it for the terrain problem you actually have.
From matching working widths across the entire chain, and guidance is what makes those matches repeatable. This is the part worth getting geometrically right, because it is free once you understand it.
Start at the front. Your tedder should spread the mown swath to roughly sixty to seventy percent of the cut width for good drydown. Your rake or merger then has to gather that full mown width and lay a windrow the baler or chopper pickup can actually swallow. The target on the harvest end is running the baler at about ninety percent of its design capacity for maximum efficiency, which means the windrow density has to match the machine. Too thin and you are burning fuel to bale air; too heavy and you plug the pickup and lose ground speed.
Auto-steer's contribution is keeping every machine in that chain on the same consistent lines so the widths line up round after round, not just on the first pass when everyone is fresh. It does not choose your widths for you. That is your math, and it is worth doing once for your equipment set. A quick way to work the numbers on a specific field, including area and matched swath widths before you ever drop a blade, is the free Field Boundary and Input Calculator at manleyfarms.com, which lets you draw the field on aerial imagery and check the geometry against your equipment widths.
One more efficiency note that also feeds the next section: a merger lifts the crop onto a belt and moves it without dragging it along the ground, which is easier on both the windrow structure and the cleanliness of the hay.
This is the honesty that keeps the whole decision straight. Guidance improves consistency at the margin. It does nothing for the two levers that most determine what your hay is actually worth: ash and drydown.
Ash is dirt in the hay, and it is set by rake type and float or tine height, not by GPS. University research from Minnesota, Penn State, and Wisconsin found first-cutting hay came out of a ground-driven wheel rake at 14.6 percent total ash versus 11.4 percent from a hay merger. Because plants only carry about six percent internal ash in grass and eight percent in alfalfa, most of the rest is soil scraped into the windrow. One ton of fourteen-percent-ash hay carries roughly 120 pounds of dirt. The mechanical reason is simple: wheel rakes are ground-driven, so their tines are turned by scraping the ground and they lift soil by design. Rotary rakes and tedders are PTO-driven, so with correct float and tine height they can gather and spread with far less ground contact. The straightest guided pass in the world still makes dirty, low-value hay if you keep raking with the tines buried.
Drydown is the second lever, and it is a spread-width and timing job. Tedding to spread the swath wide, again around sixty to seventy percent of the cut width, and inverting it exposes more surface to sun and wind and cuts curing time substantially. Extension guidance treats spread width and timing (ted a couple hours after mowing, and again the next day) as the real drydown controls. Guidance keeps your passes even, but it does not spread the hay. The spread mechanism and your timing do that.
Both of these cost far less than a full guidance system, and both move hay value more. Fix them first.
Honest tiers, because the price of any specific model changes and the correction subscriptions vary:
| Tier | What you get | Best fit |
|---|---|---|
| Assisted steer / lightbar | Visual guidance or hands-on assisted steering; you still hold the wheel | Small acreage, flat fields, tight budget |
| Full auto-steer with RTK | Hands-free steering, inch-level repeatability, works at night | Mid to large acreage, many field jobs per season |
| Passive implement guidance / steerable hitch | Keeps the towed rake or tedder on line through curves and side hills | Contoured, hilly, or irregular fields |
The adoption pattern tells the real story. USDA reports auto-steer and guidance were used on about 52 percent of midsize and 70 percent of large crop-producing farms in 2023, and on more than half of U.S. corn, soybean, cotton, and winter-wheat acres. It skews to larger operations because guidance is cheapest to justify on the tractor you already use for many jobs. One receiver serves mowing, tedding, raking, planting, and spraying. Buying it for hay alone rarely pencils out. Buying it for the whole farm and getting cleaner hay as one of many benefits usually does.
Buy for the problem you have, in this order:
The correct mental model: buy auto-steer for the tractor as a whole-farm investment, match your working widths across the whole hay chain, then win quality separately with float height, rake choice, and spread width. In that order.
Manley Farms builds free, no-login tools for exactly this kind of planning, from the Field Boundary and Input Calculator to the Spray Window Planner. They are free to use at manleyfarms.com, and if you want new tools and honest equipment guides as they land, the email list is the place to catch them.
Not as a standalone smart machine. The GPS and guidance system live on the tractor; the rake and tedder are towed implements with no receiver of their own. What you buy is tractor auto-steer that drives straighter, matched passes, plus optional implement guidance that keeps the towed rake or tedder tracking the tractor's line through curves and side hills.
No. Section control shuts off individual planter rows or sprayer nozzles over ground you already covered, and you cannot switch off sections of a rake or tedder. When haymakers say section control for hay, they mean auto-steer, which keeps every pass on its own line and stops you from double-raking or double-tedding the same strip.
Only indirectly, through more consistent passes and less overlap. The two levers that actually set hay value are ash and drydown, and GPS touches neither. Ash comes from rake type and float or tine height; university tests found 14.6 percent ash from a wheel rake versus 11.4 percent from a merger. Drydown comes from spread width and timing. Fix those first.
Often not on hay alone. USDA data shows guidance skews to midsize and large farms because it is cheapest to justify on a tractor that runs many jobs with one receiver. On small, flat, square fields a skilled operator loses little to overlap. If your fields are contoured or you run many acres across several tasks, it earns its keep faster.
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