Greenwaste compost as a substitute for turfy soil in external-soil spray seeding substrate

The aim of this study was to introduce a substitute for TS as an organic matter additive in substrate. The results indicated that the degree of influence of the three factors controlling the amended substrate is GWC > PAM > SAP. GWC improved the physical and chemical properties of the substrate, as well as the seed germination rate and seedling growth. Significant improvements can be observed with respect to the soil bulk density, soil porosity, steady infiltration rate, and anti-shearing strength (p < .01). Except for the soil nutrients and seedling height, all other indicators of the GWC substrates were better than those of the commercially available TS substrates. Principal component analysis and range analysis revealed that the optimum values of various design parameters were 40% for the compost volume content, 200 g m−3 for PAM and 100 g m−3 for SAP. Based on these results, GWC can be considered to be an effective alternative to TS for ESSS.