The harvest is the weakest link in the Polish hemp chain. The KOWR register lists 1,681 producers, and there are only a dozen or so specialised harvesting machines in the country. The rest are adapted grain combines, contractors and ingenuity. This guide sets out what is certain in harvesting technology and what follows from it when choosing machinery.
Why hemp ruins ordinary machinery. The stalk is 1.5–3 m tall and woody, and the bast fibre has high tensile strength, which is exactly what industry pays for. In the field, the same fibre wraps around reel tines, conditioner rollers, the threshing drum, baler pick-up rollers and chains. The farm press (Tygodnik Rolniczy, Farmer.pl) and advisory service (WODR) describe the same picture: clogged combines, jammed drums, frequent stoppages to clean, blunted knives. The Canadian producers’ association adds: cut 10 cm above the ground so as not to cut the most woody part, guard all exposed shafts and chains, and use smooth rollers in conditioners.
Harvesting for fibre. The stalk is cut into lengths in the field during flowering: about 60 cm is the standard for processors of shives and short fibre, and about 90 cm is the length for long fibre decortication lines, known from flax. The cut crop lies in the field for retting (breakdown of the pectins that bind the fibre to the woody core), then it is turned and baled. Turning and baling can be done by machines known from flax. The Belgian CRETES uses UNION turners for textile hemp. But a flax puller is never suitable for hemp: hemp is not pulled. A separate guide on the flax chain: from field to fibre.
The CRETES × UNION line for long-fibre hemp. The leading machine is the CRETES hemp harvester (patented solution). It cuts the stalk at two heights, removes the tops and lays out rows about 90 cm long, exactly the length accepted by long fibre decortication lines. It needs a tractor from 200 hp with 1000 rpm PTO, works at up to 1.5 ha/h, and handles plants up to 2.5 m. Next, the turner and baler from the UNION flax line take over, and the straw goes to a CRETES or Vanhauwaert line. This is the only line in our range in which harvesting, retting, baling and decortication come from one engineering group (Valtech, Flandria), with no independent suppliers to integrate. In Poland, the other machines in use are farmers’ own adaptations, contractors’ machines and windrow mowers.
Harvesting for seed. Timing: about 70% of seed mature, seed moisture 15–18% (below this, stalks shatter and wrap around the machine). Two-phase harvesting gives lower losses than single-phase (WODR). A grain combine needs adaptation: header raised to about 1 m (only the panicles are cut, not the stalks), guards on shafts and belt pulleys, sharp knives, low drum and fan speeds, and flat, non-wrapping conveyors. Rotary combines clog more often than walker combines. After harvest, seed is dried to 8–9% without overheating. Panicle mowing is offered as a service under the IWNiRZ contracting scheme (Hemp Programme).
Baling and straw logistics. The German processor Hanffaser Uckermark accepts round bales only if netted, and bales in cubes. Straw should be 60–100 cm, stalk diameter up to 14 mm, moisture up to 30% (settled at 12%). Bales must be removed right after baling, because they absorb moisture. Straw baled in spring is not bought. Kombinat Konopny (Elbląg) works the other way: plants overwinter in the field, ret “on the stalk”, are harvested in spring, and are paid 700–800 PLN/t. The harvesting technology (cutting length, degree of retting, bale form and moisture) is set by the buyer, not the farmer. Before buying a machine, read the buyer’s terms. For who buys, see purchase and contracting.
Decortication. Straw goes to a decorticator, which separates the fibre from the shives. In Poland, decortication is carried out by Lenkon (IWNiRZ experimental plant in Stęszew), Green Farms, Podlaskie Konopie and Kombinat Konopny. There is no long hemp fibre spinning mill in the country (IWNiRZ). Long flax and hemp fibre lines for plants are designed by Cretes and Vanhauwaert: bale openers, decorticators, separators, sorting, turnkey, with capacity matched to the plant’s design.
Used machines for hemp are practically unavailable on the market. This is a fact, not an opinion: only a few dozen series fibre harvesting machines have been built in Europe, and the conversions belong to contractors who do not resell them. Anyone planning fibre harvesting must plan it with the buyer and the line supplier at the same time. Anyone planning seed harvesting on 20–30 ha should choose an adapted grain combine or a service. To find harvesting, drying and decortication services near you, use the hemp exchange.
What we advise. For seed: adapt your own combine or use a service. For fibre: first a contract with the processor and their technology, then the machine. CRETES × UNION line for a plant or a group of farms building their own decortication line. We calculate machine financing in the calculator. We agree the technology in conversation: ask about hemp.