Complementary ability of three European earthworms (Lumbricidae) to bury lime and increase pasture production in acidic soils of south-eastern Australia

Mechanical incorporation of surface-applied lime (CaCO(3)) to ameliorate subsoil acidity is often not feasible because of damage to plants and erosion hazards. This paper presents results of a field cage experiment comparing the influences of three exotic European earthworm species (Aporrectodea longa, A. caliginosa and A. trapezoides) on lime incorporation and pasture production over two seasons, on two acidic soil types under pastures on the central tablelands of New South Wales, Australia. A. trapezoides was least effective in increasing pH of soil below 2.5 cm and survived poorly compared with A. caliginosa. The latter was most effective at 2.5-10 cm whilst A. longa was more effective at 10-15 cm depth. Similar complementary increases in the level of mineralisable nitrogen (MN) by both earthworm species were also observed. There was evidence suggesting that the survival of A. longa was improved by the presence of A. caliginosa. Earthworms improved pasture growth at only one site. Crown Copyright (C) 2004 Published by Elsevier B.V. All rights reserved.