A report from University of Aarhus, Faculty of Agricultural Sciences, has been produced in Danish on the losses of Nitrogen and Phospherous from perennial energy crops on agricultural and meadow soils.
The study shows that very little knowledge exist on leaching of nutrients from energy crops on meadow soils (Peat, gytje etc), and no firm conclusions can be made from this. However, on well drained agricultural soils, there is good evidence that a change from annual agricultural crops into perennial energy crops (Willow, Miscanthus, grasses) can reduce the leaching of nutrient significantly. Nitrogen leaching can be reduced by 15-35 kg N/ha/yr on clayey soils and 40-60 N/ha/yr on sandy soils.
If 15% of the agricultual land in the three Enercoast municipalities are converted into perennial energy crops the leaching of nitrogen can be reduced 570 t /yr, and for the whole country the figure is 11.000t/yr.
In general, it is concluded that perennial energy crops significantly can contribute to achieving the gioals set in by the Water Framework Directive under Danish conditions.
In addition, the report points out several optional studies to give more data on the links between energy crop cultivation and soil nutrient balances.
The report (in Danish) can be found here