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The new technologies of profitable and ecological hemp production

Leuschner J1., Kranemann H.H.2, Kuwabara H.3 (1 World Hemp Center, 2 Kranemann Gartenbaumaschinen GmbH, 3 EMRO E H G Deutschland GmbH)

1. Targets and Tasks
Considering the many different ways in which hemp can be used as a sustainable raw material, i.e. as plant biomass for generating energy, healthy human and animal feed as well as medicine, no other plant is better qualified to solve the global raw material, energy and food problems. Hemp can be used to cure illnesses in humans and in nature without harmful side effects. It grows everywhere without pesticides, helps restore the health of sick and poisoned soils and absorbs about 2.5 t of carbon dioxide per year. But, in order to benefit from these advantages, new technologies are needed which can boost productivity, lower costs drastically and are environment friendly. However, the possibilities are not yet recognised by most of the decision-makers, as shown by the state of Brandenburg with regard to the projected changes to the EU hemp and flax regulations and its effects on hemp farming [1] in Germany.

Table 1:
Effects of the projected changes to the EU hemp
and flax regulation in the Sate of Brandenburg [1]

2000 X
2000 Y
Yield t/ha
Proceeds DM/t
Straw proceeds DM/ha
EU subsidies DM/ha
Overall proceeds DM/ha
Seeds DM/ha
Fertiliser DM/ha
Machinery costs and wages DM/ha
Overall costs DM/ha
Net profit DM/ha
(The columns for 2000+x and 2000 +y were added by the author)

The table shows:

- Sustaining the current level of productivity would entail yearly losses of almost 500 DM (Deutschmarks) per hectare for the farmer from 2000+x on when EU subsidies sink to zero. That would spell the end of any progressive development, which started in Germany in 1996 when the total ban on hemp farming was lifted. Ruins of investment and more unemployed would be the consequence.
- Up to 200+y hemp yields need to be stepped up from 6.5 t/ha to at least 13 t/ha, i.e. to be doubled and machinery costs need to be reduced to 100 DM/ha. At the same time hemp needs to be grown ecologically in order to avoid continuing to destroy soil life as well as the ecological balance in nature.
- Productivity in conditioning hemp as a raw material and in processing it needs to be raised so that farmers who grow hemp can be paid cost-effective and profitable prices. The increase in productivity and quality in this area can only be justified as long as environment friendly technologies are used.

2. Material and Method
The above-mentioned requirements are high but they can be met if outdated methods are replaced by innovative production systems. There will be progress when new methods in engineering are successfully combined with elements of automation, biotechnology and other innovative disciplines so as to form a unity. Here some results are presented to illustrate how such systems are being worked on.

3. Results
The hemp harvesters based on the double-cylinder principle [2] from KRANEMANN Horticultural Machinery Plc (Kranemann Gartenbaumaschinen GmbH) in Mecklenburg-West Pomerania have become an integral part of an innovative system for growing and harvesting hemp, which is confirmed by the level of development (table 2 - attachment 1) reached in 2001.
The machines separate the plants from their sites by means of two contra-rotating cutters. The height of the stubble can vary from 10 to 30 cm. Two contra-rotating, vertical pick-up cylinders fitted with guided teeth move the plants chopped from their site in their original and mostly upright position to the middle of the two cylinders and further on to two or three circular saw disks. These are positioned above one another, at levels of 60 or 45 cm respectively, so that the plants are chopped into three or four parts before they are released from the pick-up cylinders and their teeth. Now, falling in a trajectory, they hit the soil and form a swath (picture 1). As a result of the different heights from which the parts of the stems have been released, they form three or four separate layers in the swath: The lowest parts drop onto the stubble, followed by the second layer from the middle parts and, finally, on top of all there are the uppermost, seed-bearing parts and leaves that had to go the longest distance in the trajectory.
Within the swaths consisting of three to four layers the produce dries, dew rets and allows the seeds on top to ripen. As soon as the straw is dry at 85% and thus ready to be stored, the swaths are collected by straw balers (picture 1) and pressed into round or rectangular bales. Then they are taken to the storage rooms. The hemp seeds are threshed and pre-cleaned in a stationary manner in the hemp processing plant.
The harvester’s vertical cylinder principle has demonstrated its virtues since 1998, which make it especially suitable for increasing the productivity of the machine system. The merits are high efficiency and reliability even under severe harvesting conditions, for example rain, bad roads, lying stalks, which are lifted by the steered teeth on the cylinders, and strong, woody stems, which makes it possible to harvest even in winter in order to profit from spells of frost for the retting of the hemp straw. The twisting of hemp straw around rotating machine parts, which occurs so frequently with ripe hemp and in humid weather and which is so typical of other hemp harvesters, can be almost totally avoided. Consequently, the time during which the machine is performing in the field is bigger than 95% (z > 0.95). So the machinery costs are reduced, too, as shown by a calculation based on the standardised values for agricultural machinery [3] (picture 2). Machines susceptible of frequent breakdowns (z > 0.95) raise the machinery costs rise due to increased periods of standstill when the crop stands are dense and the yield is high.
As higher yields are necessary to make hemp farming profitable, hemp harvesters based on the vertical cylinder principle have a good chance of maintaining their worldwide peak position. Their unparalleled performances of 700 ha in the campaigns of 1999 and 2000 and the possible doubling of their working width qualify them for harvesting industrial hemp. Comparative tests of harvesting machines in 1999 and 2000 confirm this fact.
The vertical cylinder harvesters are compatible with all the fibre processing systems in Germany, like those of the "Gahmer" and "Temafa" companies. In order to improve the homogeneity of the infeed during fibre processing, the KRANEMANN Company has created a stationary compact bale opener, which unravels the straw from the bales and cuts it into sections whose length can be adjusted by the user. Attributing this function, which is at times integrated in the harvesters, to the stationary facilities, improves the reliability of the machine system and the output quality.
In co-operation with the Institute of Agricultural Technology (Institut für Agrartechnik e.V.) at Potsdam-Bornim the KRANEMANN Company has developed a special decorticating machine, which has been tested successfully [4]. The processes of crushing the stalks, decorticating them and removing the hurds appear to have been perfectly solved. Tests will be carried out under ordinary working conditions in the hemp campaign of 2001.

4. Biotechnology in hemp farming
Preliminary investigations into the system of effective micro-organisms (EM technology), developed by the Japanese scientists Teruo Higa, have raised new possibilities for hemp farming. His special combination of beneficial micro-organisms cause soil life that has been destroyed by chemicals to be reactivated. The micro-organisms in EM, such as photosynthetic and lactic acid bacteria, yeast fungi and actinomycetes, belong to the group of valuable and beneficial micro-organisms. Among these the photosynthetic bacteria, for example, will boost photosynthesis. In using the solar energy absorbed by the soil, they form anti-oxidants, amino acids, sugar and many active substances which promote plant growth. Thus, it will be possible in hemp farming.

- To raise yields and improve the quality of hemp plants in less time and with less money and energy. According to Prof. Higa [5] yields could be tripled. Preliminary hemp farming tests in Poland in 2000 have proved successful.
- Whereas rot losses can be expected to drop, dew retting may be accelerated. Dutch farmers store hay fermented with EM and containing 30% of moisture in bales wrapped in plastic without rot losses in the open. As to hemp, this could save transport and storage costs as well as losses through rot.
- It is possible to reduce damage to hemp fibres through oxidation by means of the anti-oxidative properties of EM. Greater elasticity in hemp fibres, which was discovered in preliminary tests carried out by the Institute of Natural Fibres (INF) in Poznan, may thus be accounted for.
- Wet conditioning of hemp, such as water retting, which is no longer acceptable due to water pollution through rot, is thus given the chance of being revived on a higher level.
- EM having been successfully used in agriculture for green crop silage, it should be tested for water retting hemp as well.
- Preliminary tests, carried out by the author, show that the anti-oxidative properties of EM can prolong the storage qualities of hemp seed and hemp oil used in cosmetics and in foods, thus sustaining the positive effect of unsaturated fatty acids in hemp seed against the free radicals of aggressive oxygen ions.

Within the World Hemp Centre, Ltd (WHC), the recent collaboration with the Poznan Institute of Natural Fibres will be continued in the areas mentioned above and supported by the newly founded EMRO (Entwicklung- u. Handelsgesellschaft Deutschland GmbH).

5. Conclusions
Previous experiences in reviving the economically useful hemp plant [6] at the close of the past century and at the beginning of the new millennium have triggered off many initiatives to use this plant in order to solve regional and global issues. More new ideas, new technologies and a final victory over the prejudices against the hemp plant are now necessary to sustain what has already been achieved and to continue being successful. Combining disciplines that have been working separately in technology, biology and other progressive branches in the sciences and the humanities offers new opportunities for successfully solving the above-mentioned tasks through innovations. However, since the issues are complex, the intellectual, financial and material capacities must be concentrated nationally and internationally. So, the World Hemp Centre, Ltd (WHC) is going to focus both on international division of labour and co-operation at its shareholders’ meeting at the Insitute of Natural Fibres in Poznan on November 14 and 15, 2001 and at the WHC council’s preparatory session at Bluecherhof (Mecklenburg-West Pomerania) on October, 8 and 9, 2001. Anyone interested in attending and guests will be heartily welcomed.


- 1. Schulze, Dr.: Informationsblatt des Ministeriums für Landwirtschaft, Umweltschutz und Raumordnung des Landes Brandenburg (2. 7. 2001);
- 2. Kraneman, H.-H.; Leuschner, J.: "Einsatzerfahrungen Hanfvollernter Blücher 02" in Tagungsheft - Hanf - der Fachtagung "Stoffliche und energetische Nutzung von Biomasse im Land Brandenburg" anläßlich Landwirtschaftsausstellung BRALA 1999;
- 3. Autorenkollektiv: "Daten für Betriebskalkulation in der Landwirtschaft" KTBL Taschenbuch Landwirtschaft 1998/99, Landwirtschaftsverlag GmbH, Münster-Hiltrup;
- 4. Fürll, C.; Ackermann, J.; Idler, C.; Kühne, G.: "Trocken- und Naßaufschluß zur Fasergewinnung aus Hanf" in Tagungsheft - Hanf - der Fachtagung "Stoffliche und energetische Nutzung von Biomasse im Land Brandenburg" anläßlich Landwirtschaftsausstellung BRALA 1999);
- 5. Higa, T.: "Eine Revolution zur Rettung der Erde" OVL Organischer Landbau-Verlagsgesellschaft GmbH ( 192 S.) 2000;
- 6. Herer, J.: "Hanf - Wiederentdeckung der Nutzpflanze Hanf, Cannabis, Marihuana". Auflage 1993, Verlag Zweitausendeins, Frankfurt Main.

Technical Data of Vertical Cylinder Hemp Harvester
( State of development 2001)
Type designation of machine:
Hemp harvester "Bluecher 02-2"
Working width:
3.3 m
Working speed:
4 - 12 km/h
Area treated per hour:
1-3 ha/h
Prospective campaign performance*:
600 - 800 ha/a
Flow rate:
10-30 t/h
Adjustable cutting heights:
10-40 cm
Type of cutting tools:
rotary cutters
Number of cutters for separating stalks:
3 videa-fitted circular saw disks per cylinder
Carrier machine:
New Holland 2205
Required overall performance:
140 kW
9 t
Adjustable height of driver’s cab platform:
200-300 cm
Mass of hemp harvester:
2 t
Required performance of working systems:
70 kW
Power transmission and control:
*campaign performance achieved since 1999 with same machine type
700 - 1000 ha/a in three to four month campaign

Engineered and manufactured by:
Kranemann Gartenbaumaschinen GmbH
Hof 2
D-17194 Bluecherhof
fon: 0049 (0) 39933 71908
fax: 0049 (0) 39933 71910
e-mail: Kranemann.Bluecherhof at t-online.de

published Monday 6 October 2003 13:57