Using AD in the establishment of newly planted trees and energy crops

In Scotland, four field trials are taking place to assess the use of anaerobic digestate in the establishment of newly planted trees and energy crops.

The first is managed by David Jarvis Associates in partnership with Forest Research.

The trial is designed to examine whether application of liquid and solid anaerobic digestate products applied to tree planting pits at the time of planting would enhance soil conditions and tree growth, on its own or in conjunction with a PAS100 compost product.

Meanwhile, at Heartlands brownfield regeneration site, Polkemmet, Earthcare is trialling the planting of five species of hardwood – red alder, cherry, eucalyptus, poplar and birch – into poor quality soils that have been improved with biofertiliser and BSI PAS 100 compost.

In the final two trials, the Forestry Commission aims to establish whether silver birch can be grown for biomass production on two post-industrial sites with the addition of compost and solid biofertiliser, also known digestate fibre. The first site, Dalquhandy, is a former open cast coal mine, while the second, Addiewell, in West Lothian, was previously used as an oil shale spoil tip.