AEROBIC COMPOSTING OF PLANT WASTES AND THEIR EFFECT ON THE YIELD OF RYEGRASS AND TOMATOES

Vine branches, rice husks and flax residues were composted. The dynami cs of biomass carbon, C/N ratios and nitrification were studied. The h ighest quality level and the most stabilized composts with the highest values of total N (1.3-1.6%) and the smallest C/N ratios (8.0-9.0) we re found with the vine branch composts. Compost application significan tly increased the yield of tomatoes (24.0-61.1%) and the quality of fr uits compared to soil treated with mineral fertilizers and manure. Ino culation of the vine branch compost with a Cephalosporium sp. had a po sitive effect on the yield and the quality of both ryegrass and tomato es. The stabilization of the microbial biomass C level in the composts coincided with the beginning of intensive nitrification. Inoculation lowered the conductivity values and nitrate contents in all composts. It appeared that when nitrate N concentrations in the composts were mo re than 5% of the total N, NO3 accumulation in the fruits could result . However, the results can be applied to similar substrates and condit ions of composting.