Evaluating effects of sewage sludge and household compost on soil physical, chemical and microbiological properties

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment Vol. 19; no. 3; pp. 237 - 248
• Main Authors: Debosz, Kasia, Petersen, Søren O, Kure, Liv K, Ambus, Per
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2002; Elsevier
• Subjects: Activity; Agronomy. Soil science and plant productions; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Household compost; Microbial; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Sewage sludge; Soil fertility; Soil structure; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Denmark; Scandinavia; Europe; Household compost; Soil structure; Activity; Microbial; Soil fertility; Sewage sludge; Biological properties; Microbial activity; Compost; Organic waste; Enzyme; Household refuse; β-Glucosidase; Chemical effect; Glycosidases; Waste reuse; Hydrolases; Chemical properties; Domestic refuse; O-Glycosidases; Loamy sand soil; Organic amendment
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/S0929-1393(01)00191-3

Recycling of organic wastes within agriculture may help maintain soil fertility via effects on physical, chemical and biological properties. Efficient use, however, requires an individual assessment of waste products, and effects should be compared with natural variations due to climate and soil type. An 11-month incubation experiment was conducted between April 1998 and March 1999, in which a sandy loam without or with anerobically digested sewage sludge (4.2 t dry matter (DM) ha −1) or household compost (17 t DM ha −1) was incubated under constant laboratory conditions at 10 °C, as well as in the field. The following properties were monitored: wet-stability of soil aggregates, clay dispersibility, hot-water extractable carbohydrates, resin-extractable P i, inorganic N, biomass C and N, PLFA profiles, FDA hydrolysis activity, β-glucosidase activity and CO 2 evolution. In general, effects of waste amendment were positive, but moderate compared to the dynamics observed in unamended soil, and mainly occurred in the first several weeks after amendment. The temporal dynamics of inorganic N, FDA hydrolysis activity, biomass C and PLFA composition appeared to be faster under the fluctuating climatic conditions in the field. To evaluate accumulated effects of repeated waste applications, soil was also sampled from a field trial, in which the sewage sludge and household compost had been applied at the same rates as in the incubation study for three consecutive years. Sampling took place after the final harvest, i.e. 5 months after the final waste application. Compost amendment had increased potentially mineralizable N by a factor of 1.8, and sludge amendment had increased the amount of resin-extractable P i by a factor of 1.6. However, there were no accumulated effects of waste amendment on the fraction of soil in wet-stable aggregates, or on the microbiological properties tested, which supported the observation from the incubation study that effects of organic wastes were transient.