Applying digestate to existing reed canary grass energy crops on brownfield land to increase yield

This project involves the application of liquid fraction digestate as a fertiliser on established Reed Canary Grass energy crops.  This project comprises three trial sites situated in north east England -  a former landfill site (Warden Law), a former iron and steel works and tip (Teesside Barrage), and a site made from dredgings from a coffer dam (Teesquay Millennium foot bridge).  

All the sites were planted with reed canary grass (Phalaris arundinacea) at least four years ago and were part of a wider project that demonstrated the suitability of the energy crop on challenging brownfield soils - The BioReGen Life project (2005-2010) and WRAP trailblazer project (OBF001-012) and monitoring (OBF010-005).  

This trial follows on from this work and will examine the effect the application of digestate has on crop quality and yield.  It will also evaluate the cost and logistical implications of applying digestate to land. 

Trial design and monitoring

The three demonstration field trials involve one spring application of liquid fraction digestate to half of the crop stubble, in two consecutive years.  The other half of the crop will act as a control.  Rates of application are based on the nutrient requirement of reed canary grass (50kg N/yr).

Application rate of digestate:

Crop yields (oven dried tonnes) will be measured annually, and a full suite of fuel test analyses will be undertaken to assess any effects the digestate has on fuel properties. 

Final results will be available from March 2014