In Sweden, Salix (Willow) is a popular method for treating leachate. But Salix in principle requires flat arable land for a good establishment but also to be able to be rationally harvest by machine.
Many of today’s Salix plantations on and around a landfill do not meet the cultivation’s requirements, which is why the maintenance tends to be mismanaged and harvesting does not take place at the 3-4 year intervals required to be an effective purification step.
By planting a crop that does not need to be harvested more than every 10-15 years and with conventional forest machines would provide significantly better cultivation and reduced costs. Planting on an old landfill is in principle impossible with Salix, which requires a lot of chemical weed control and hand planting.
Could planting with 2m poplar shoots be established directly without any intercession?
“Mr Poplar” Lars Cristersson has been willing to assist with knowledge and planting material and is convinced that even on a wild landfill it would be possible if they were planted 1m deep. Completed with stem protection, it is clear of both competition from weeds and animals.
To prove the thesis, poplars have been planted at Merab’s Rönneholm landfill outside Eslöv. With an earth auger, it comes down to a depth of 1 m in pattern of 3x3m, which can be adjusted to 2×4.5m to fit irrigation. Poplar is almost as effective as Salix on growth but many times better than a poor Salix cultivation and will not need as much maintenance. We will come back and tell you how the cultivation is progressing.
The cultivation is irrigated in the same way as Salix, for example with LWIS.
The trial is conducted within a project “Ökad Energiskogsodling genom Samverkan från Producent till Användare”
Laqua Treatment AB 