Humic fractions of molecular weight above (HSp) and below (HEf) 3.5 Kds obtained from faeces of earthworms ( Allolobophora rosea and A. caliginosa), were compared with the exhausted culture broth of Actinomycetes (EAB) isolated from the same source. Hormone-like activity and efficiency of nitrate uptake by rice seedlings were stimulated by EAB and HEf, while HSp showed only negligible activity. EAB showed a stimulatory action on plant growth (dry weight) and affected the K, Ca, Mg, Fe absorption during the first two weeks of plant growth.