Effect of sewage sludge on soil humus content. The influence of sewage sludge application on physical and biological properties of soils. Proceedings of a Seminar organized jointly by the EEC, Directorate-General Science, Research and Development and the Byerische Landesanstalt für Bodenkultur und Pflanzenbau, Munich, BRD, June 23-24. 1981 - Koskela, Inkeri (de, 1983)
Keywords: lietelanta; humuspitoisuus; sewage sludge; humus content