With respect to digestate disposal (Fig. 8), for net environmental benefit, the maximum transportation distance for disposal of digestate from cattle manure, corn silage and MSW feedstocks
should be within 95, 19 and 33 km radius, respectively. Digestate separation, loading, transport and spreading on arable land normally influence the energy inputs for digestate processing and handling. However, these differences in environmental impacts of digestate disposal were mainly based on values of active fertilizer ingredients, hence, value as mineral fertilizing substitute. For example, cattle manure shows 10, 7 and 3 times higher active fertilizer ingredients in P2O5 (triple superphosphate fertilizers), K2O (potassium sulfate) and NH4eN (ammonium nitrate) per tonne of dry digestate, respectively, compared to corn silage (Poeschl et al., in press).