The effects of ammonia and ethylene oxide in animal manure and sewage sludge on the seed germination and root elongation of Brassica parachinensis

Aqueous extracts (1%) of chicken manure, pig manure, activated sludge and digested sludge were stored in sealed polythene bottles at 22 ± 3°C for a period of 65 days. Aliquots of the extracts were withdrawn after 2, 16, 27 and 65 days and applied to seeds of Brassica parachinensis (flowering Chinese cabbage). In general, manure had higher contents of ammonia and ethylene oxide than sludge and severely affected root growth and seed germination. The effects on root elongation and seed germination in manure extracts, especially chicken manure extract, closely followed the contents of ammonia, and, to a lesser extent, ethylene oxide. Such phenomena were not so obvious in the extracts of sludge, particularly activated sludge.

When EDTA was added to the 65-day old extracts of the four wastes, the toxic effects of activated sludge extracts which contained the highest level of heavy metals (manganese, zinc, copper and iron) were reduced. Copyright © 1983 Published by Elsevier Ltd.