ATB set up the first trial areas with fast-growing tree species such as poplars and willows back in 1994. The aim was to find out which trees grow quickly and undemandingly so that they could be harvested at regular short intervals and used for energy. This led to extensive long-term trials, some of which are still ongoing today. When Energy Crops GmbH, or ENC for short, was founded in 2010 to utilise agricultural wood commercially to provide energy in Berlin and the surrounding area, it faced a number of challenges. So ATB and ENC began their joint research and development work. On 13 March 2025, after 15 years of working together, the two partners hosted the harvest event "Agricultural wood for energy use" to provide practitioners, farmers and interested parties with insights into current research and techniques in agricultural wood cultivation.
The potential of agricultural trees is huge. Unlike trees in traditional forestry, fast-growing woody plants such as poplars, willows or robinia can be harvested every three to four years and then sprout new bushes from the rootstock. Once established as a windbreak in an agroforestry system or as a pure short rotation coppice, areas can be managed for up to 20 years with stable, high yields. Wood chips are harvested, which can be burnt to generate energy and heat. This extensive farming method is the reason for the positive ecological effects and the low carbon footprint of energy wood cultivation. ATB was able to prove that short rotation coppices have a positive effect on biodiversity, humus formation and the permanent storage of carbon in the soil, i.e. carbon sequestration.
The ENC planted around 2,000 hectares of agricultural timber with poplars between 2010 and 2015. ATB accompanied the activities and carried out numerous investigations on the areas. The collaboration not only resulted in important findings on efficient logistics chains and new methods for low-loss woodchip storage. ATB developed a new harvesting machine, partly because of the large area potential. This mow chipper cuts the wood just above the rootstock and shreds it into woodchippings in the same step. Together with ENC, ATB demonstrated the practicality of the new machine.
From 2010 onwards, the cultivation of agricultural timber developed strongly. In Brandenburg alone, well over 2,500 hectares were planted by various investors. However, the amendment to the Renewable Energy Sources Act (EEG) implemented in 2014 led to a noticeable reduction in remuneration for renewable electricity from biomass. As a result, demand for woodchippings stagnated and also declined due to the warmer winters. Prices fell and the profitability of agricultural wood cultivation came under pressure. As a result, many investors withdrew from the area. The ENC took over some of their sites, while others were converted back. ATB was working against this trend. In 2019, the institute built a wood chip heating system to supply heat to the institute's premises and was able to cushion the energy crisis in the following years thanks to its greater independence from fossil fuels. ATB also planted additional hectares with various poplar varieties. These new varieties are characterised by better resistance to drought, fungal diseases and beetle infestation and thus stabilise the yield potential of agricultural timber cultivation.
Now, on 13 March another harvest event was held. Numerous interested parties and practitioners attended the harvesting of ten hectares of a poplar stand. Ralf Pecenka, Head of the Working Group Process Engineering for Energy Crops at ATB, says: “We are delighted about the many years of good cooperation with Energy Crops, with which we are driving forward the development of the agricultural wood industry. With the joint event, we were able to further increase awareness of the renewable energy source and provide practitioners with insights into an existing system.”
ATB will continue to support the ENC with a wide range of issues such as grain size analyses, dry matter losses during storage and much more. And new tasks will not be long in coming. The utilisation of paludibiomass, i.e. harvested products from rewetted moorland areas such as sedges or reeds in the state of Brandenburg, both for material and energy purposes, is an exciting new field of activity in which both partners are successfully continuing their collaboration.
Selected publications on the topic:
Cultivation & Harvest
- Environmental Effects over the First 2½ Rotation Periods of a Fertilised Poplar Short Rotation Coppice
- Harvest technology for short rotation coppices and costs of harvest, transport and storage
- An efficient harvest line for Short Rotaion Coppices with a new Mower-Chipper
Storage
- Open-air storage of fine and coarse wood chips of poplar from short rotation coppice in covered piles - ScienceDirect
- Cold air ventilation for cooling and drying of poplar wood chips from short rotation coppice in outdoor storage piles in Germany - ScienceDirect