Presence of Plant Growth Substances in Earthworms demonstrated by Paper Chromatography and the Went Pea Test

Abstract

REPORTS have been published describing increases in growth and vigour of pasture in New Zealand following the experimental transplantation of lumbricid earthworms of the species Allolobophora caliginosa into soils where they were not normally found^1–3. Fourteen species of Lumbricidae are known in New Zealand, although the family is not native to the region⁴. Since they have been introduced accidentally during the past hundred years or so there has not been sufficient time for them to spread by natural means to all areas under grass. The increased pasture yields may be due to the presence of plant growth-promoting compounds elaborated by earthworms and secreted by them into their casts and thus into the soil. A similar suggestion was, in fact, advanced by Hopp and Slater⁵, who found in pot experiments that the addition of both living and dead earthworms was associated with increased growth of the test plants.