FIELD: agriculture; biology; effluents treatment; environmental control. SUBSTANCE: freshly sawn wastes and trimmings resulting from working softwood and/or leaf wood are laid to form mat 20-100 cm thick. Biological material, such as activated sludge formed in excess in secondary settling tanks, is filtered through these sawdust mats, sludge-to-wood wastes volume ratio being at least 3:1. Filtrate thus-obtained is collected and directed to aeration basin (aerotank) to be recycled. Upper layer of sawdust containing dewatered activated sludge is scraped off mechanically. These scraped sawdust/sludge layers are used to form piles up to 1.5 m high on open platforms and/or they are charged into special containers for compost formation. For this purpose, piles and/or containers are inoculated with earthworms. Activated sludge is periodically poured onto piles. Some 15-30 days before coming of stable frosts, piles for winter-time compost formation are protected by cold-insulating cover. Resulting earthworm-enriched composted fertilizer("vermicompost" from Latin word "vermis" - "worm") is constituted by effluents deposit and softwood wastes and it represents product of light-greyish-brown color slightly smelling earth. It has following composition: mobile forms of nitrogen about 1.5 g/kg dry matter, calcium 5-6 g/kg dry matter, phosphorus as calculated on P2O5 basis 5-6 g/kg dry matter, mobile potassium ((K2O)) 0.20-0.25 g/kg dry matter, pH being 6.0-6.5. EFFECT: excellent agricultural fertilizer available all around the year. 6 cl
