Nutrient imbalance, mainly due to low K and high Ca and/or Mg concentrations, was a plausible explanation for low growth response to digestate fertilisation by beetroot following harvested grass-clover biogas ley. To derive the full benefit of a transition to a biogas nutrient management (BG) system, extra nutrients except for N may need to be added, especially if digestate supply is divided between many crop positions in the rotation. This is probably of extra importance on sandy soils such as that used in this experiment
