The effects of the carbonization product of separated communal waste as an additive to the soil was studied on the germination, quantitative growth and yield parameters of maize (Zea mays L.), bean (Phaseolus vulgaris L.) and tomato (Solanum lycopersicum L.). The product was tested on three soil types with different humus content and mineral composition in doses of 1, 10 and 20 g of additive per kg soil, with application before seeding or after plant emergence, under greenhouse and field conditions. It was found that plants utilized the nutrient content from the carbonization products in both methods of application and that the stimulatory effect on the germination, fresh and dry mass and yield parameters of the treated plants was dependent on the plant species, soil type, dose and method of application. A significant effect of the additive was found on the germination of bean, which increased by 8-22% over the control. Fresh and dry mass increased by 18-62% in maize and by 2-30% in bean when the additive was applied under greenhouse conditions. In the field the additive was found to have a positive effect on the average mass of tomato fruits and maize cobs, and on the yield per plant.