Liming is the cheapest way to correct soil pH, but a lime spreader is chosen differently from a mineral fertiliser spreader. The difference is not in the brand or the price, but in the material: lime weighs several times more than granules, flows worse, and the rate is counted in tonnes per hectare, not kilograms. A machine that handles saltpetre perfectly can stall after the first hopper load when the lime is damp. Below is what is really worth looking at when choosing.
Lime is not fertiliser — and that is where all the differences come from
A mineral fertiliser rate is usually 100–300 kg/ha. A lime rate is 1–5 t/ha, that is, several times more mass on the same field. Everything else follows from this: the hopper must be larger, the chassis stronger, and the floor conveyor must feed material that is not free-flowing. Lime can be damp, lumpy and abrasive — three properties that granulated saltpetre does not have. That is why the question is not “will this spreader spread lime”, but “will it spread it evenly all season, and not just over the first five hectares”.
Three forms of lime — and three different demands on the machine
Granulated lime is the easiest: it behaves much like fertiliser, gives the greatest working width and does not dust. Powdered lime (meal) is the cheapest per tonne of CaO, but requires dust covers — without them the material blows back onto the tractor and the operator, and spread uniformity depends on the wind. Damp lime is the hardest: it does not flow, bridges over the conveyor and sticks to the hopper walls. If the farm buys lime wherever it happens to be cheap, the machine must handle all three forms — and that narrows the choice more than any other parameter.
Floor conveyor: chain or belt — this is the one decision
In large trailed spreaders the material is fed to the discs by a floor conveyor, which comes in two designs. A rubber belt moves material by friction — with dry granules it works flawlessly, but with damp lime, compost or manure it can slip over the drive rollers. The flow then becomes uneven, and spreading is sometimes interrupted intermittently, which cannot be seen from the cab. A chain conveyor with scraper slats removes material from the floor mechanically, regardless of its moisture, and at the same time cleans the bottom of the hopper. Güstrower GDK is built this way — and this is the reason this design appears on the list for liming at all, rather than only for fertilisers.
Working width — this is where the most is promised, and most often
Working width given in catalogues almost always refers to mineral fertiliser. For lime it is noticeably smaller and results from the physics of the material, not from the machine's design: heavy, irregular material does not travel as far as granules and does not lay down an even cross distribution. The difference is large: granulated lime spreads wider than powdered lime, and both narrower than mineral fertiliser — exact values for a specific model and spreading unit are given in the machine data sheet, because they also depend on which discs are fitted. If a seller quotes one figure for fertiliser and for lime, that is not an advantage of the machine, but a sign of no distinction — and it is worth asking about this in writing.
Payload: limited by the permissible gross weight, not the hopper capacity
This is the most common selection mistake. Hopper capacity is given in cubic metres, while lime is bought by the tonne — and with lime the hopper is filled “to weight”, not “to the edge”. A sample calculation anyone can check on their own material: at a bulk density of about 1.2 t/m³, a 10 m³ hopper is about 12 t, so at a rate of 2 t/ha one load covers roughly 6 ha. But that is only half the answer. The other half is the permissible gross weight: in the GDK line, single-axle machines have a DMC of 12,000 kg, two-axle machines 22,400 kg — and this figure, not the capacity, determines how much lime may actually be taken to the field. A farm that counts only cubic metres buys a hopper it is not allowed to fill.
Precision: when ISOBUS for liming really pays off
Liming is a job where variable rate makes more sense than with fertilising: soil pH varies within a single field more than nutrient content does, and pH tests are in any case done on a grid. A liming map from such tests goes into the terminal and the machine changes the rate by itself — this is precision fertilising VRA, and with material bought by the tonne the saving is visible immediately. In addition there is GPS Section Control, which switches off sections at headlands and in wedges, and ISOBUS, thanks to which the machine works with the tractor's terminal instead of adding its own display to the cab. It is worth considering on-board weighing separately: with lime it is the only way to know how much actually came off a hectare — volume misleads all the more the damper the material is.
Wear: lime is an abrasive material
A lime spreader wears out faster than a fertiliser spreader — that is normal, not a fault of a particular brand. Check what the exposed parts are made of: the hopper floor, conveyor scrapers, discs and vanes. HARDOX steel on the wearing parts is the difference here between one season and several. The second question is even more important and almost nobody asks it before buying: will parts for the machine be available in five years, and can they be identified from the assembly drawing? For the GDK line the catalogue is open — Güstrower GDK parts with drawings of the assemblies.
One machine for lime and fertiliser — when it makes sense
A dedicated lime-only spreader pays off for a contractor and a very large farm. Below that scale one looks for a universal machine — and two things decide here: interchangeable spreading units (separate discs for lime and separate for mineral fertiliser) and a conveyor that can cope with both materials without reconfiguring the floor. If a machine requires a compromise — for example, it spreads lime well but loses half its width with fertiliser — it is better to know this before buying than in April. We have described the comparison of fertiliser spreaders separately: how to choose a fertiliser spreader.
Before you sign — six questions for the seller
First: what is the working width separately for granulated lime and for powdered lime. Second: is the floor conveyor a chain with scrapers or a belt. Third: what is the permissible gross weight and how many tonnes of lime may be loaded in accordance with it, not in accordance with the capacity. Fourth: are dust covers included if you plan to use powdered lime. Fifth: does the machine have on-board weighing and does the data go to the tractor's terminal. Sixth: where the wearing parts are kept and what their delivery time is. Written answers are worth more than any figure in a brochure.
What next
The whole line of trailed spreaders with chain conveyors that we supply is described on the Güstrower GDK page — four models, capacity 6–16 m³, rate adjustable in the range 40–16,000 kg/ha, ISOBUS compatible. The wider context is all the fertilising machinery, which we combine into one system: spreading of lime and loose fertilisers, slurry application into the soil and field logistics. If you want to match a configuration to your hectares and to the material you actually buy, write to us — we match the machine to the farm, we do not sell off the shelf.