Influence of composted sewage sludge on the wood yield of willow short rotation coppice. An Estonian case study

The study assessed the effect of composted municipal sewage sludge on the wood yield of an experimental willow short rotation coppice (SRC) during the second harvest cycle. The mean values of BOD7, total N and total P met the legislative limits set to prevent groundwater pollution at the soil depth of 40 cm. We demonstrated that more productive plants of the first harvest cycle could lose that trait during the next. The second harvest cycle was more productive in terms of wood yield than the first for plants of both treatments. Sludge treated willows had significantly higher wood yield.