RESPONSES OF INVERTEBRATES TO PAPER SLUDGE APPLICATION TO SOIL

An area of sandy arable soil which had been treated with paper sludge (200 t ha(-1)) was found to support a much greater abundance of lumbri cid earthworms (Aporrectodea caliginosa and Octolasion cyaneum, endoge ic species) at the end of an exceptionally dry summer than adjacent un treated soil. In soil selection tests the endogeic A. rosea showed no discrimination between arable soil with and without paper sludges prod uced by two different processes. It did, however, strongly select sand y moorland soil which had been treated with either paper sludge, and h ad a pH near 7, over unamended moorland soil of pH 3.9. Similar respon ses were observed for the herbivorous gastropod Helix aspersa. The ane cic lumbricid Lumbricus terrestris drew substantial amounts of both ki nds of paper sludge into its burrow, although comparatively slowly com pared with decaying leaf material. Helix aspersa readily consumed one of the two sludges. Implications of sludge application for faunal abun dance and diversity, and likely effects on soil fertility, are outline d. (C) 1998 Elsevier Science B.V.