FIELD: agricultural biology. SUBSTANCE: method involves placing substrate samples of different quality in netted bags in radially symmetrical position within cylindrical vessel so that bags are arranged about one of samples; putting 10-50 worms into central sample; sorting out all substrate samples in 3-5 days and substituting dead worms with live worms; separating cocoons; replacing central substrate sample by one of peripheral substrate samples during laying of new cycle; determining substrate preferendum by number of worms encountered in substrate sample as well as by number of laid cocoons. EFFECT: increased efficiency and improved precision of data obtained. 2 cl
