An addition of a small amount of fertile soil to an artificial compost with calcium cyanamide, accelerates the formation of ammonia in the compost, and no difference in the rate of reaction was found regarding the moisture content of the soil used. If the calcium cyanamide compost has a deleterious influence on the nitrification in the soil or not, depends on the quantity as well as the degree of decomposition of the compost used. The well ripened calcium cyanamide compost behaves equally effective as the compost of any other nitrogen source and has no harmful influence on the nitrification. Consequently the well ripened product can safely be applied to the dry-farm or the paddy-field.