Earthworm induced mineral weathering: preliminary results

Carpenter, D., Hodson, M.E., Eggleton, P. and Kirk, C. (2007) Earthworm induced mineral weathering: preliminary results. European Journal of Soil Biology, 43 (Supplement). S176-S183. doi: 10.1016/j.ejsobi.2007.08.053

Abstract/Summary

The role of earthworms in mineral weathering was investigated. The minerals anorthite, biotite, olivine, smectite and kaolinite were mixed with a sterilized manure substrate. Two treatments were used: minerals with earthworms and minerals without earthworms. The earthworms were established in mesocosms and left to process the substrates for 1, 2, 4 and 6 months. Four sacrificial replicates were used per time period. Changes in mineralogy were analysed using X-ray diffraction. Weathering of anorthite, biotite, smectite and kaolinite appears to be accelerated by the earthworms. There was evidence for the transformation of smectite to illite and the formation of a new mineral phase from kaolinite. Olivine appears not to be weathered by earthworms. Different minerals also appear to weather at different rates. (c) 2007 Elsevier Masson SAS. All rights reserved.