Experimental treatments in the three experiments.

Fertilizer blend ratios are expressed according to nitrogen supply. The numbers in the treatment codes refers to the blend ratio expressed in % dry matter. No fertilizers were added for the negative control experiment. The species Arthrospira platensis and Rhodobacter sphaeroides were used for respectively the microalga (MA) and purple non-sulfur bacteria (PNSB) fertilizers. Two ryegrass pot trials were performed with either individual (a) or microbial fertilizer blends (b). AHB: aerobic heterotrophic bacteria; SF2: conventional organic fertilizer.