The field trial was set up with 5 blocks along the slope gradient each containing a control and three substrate treatments(see Appendix Fig. A1). Each plot included four grape vine row sand three inter-rows, respectively. The three substrate treatments were: biochar alone (referred to hereafter as ‘biochar’), compost alone (‘compost’) and compost produced together with initially 20 vol% biochar, i.e. the biochar was already present during the composting process (‘bc-compost’)