6533b870fe1ef96bd12cfa19

RESEARCH PRODUCT

Leaching of n and c from birch leaf litter and raw humus with special emphasis on the influence of soil fauna

subject

description

Abstract To examine the role of a community of soil animals in N-mineralization and C fluxes in dead organic matter, we established a microcosm system with substrates composed of: (a) birch leaf litter; (b) raw coniferous humus; and (c) litter on humus. Every 3–4 wks the substrates were irrigated with distilled water, and the amounts of NO5-N, NH4-N, total-N and total-C (as well as humic substances at one recording) in the leachates were analyzed. At the end of the experiment, water-soluble and exchangeable forms of N were measured in the test materials. The differences in the release of N were clear both between the replicates with and without soil animals and between the different forms of N. From wk 10 onwards the fauna enhanced significantly the leaching of total-N and NH4-N from the humus alone. The release of total-N from the litter alone was also increased by the fauna. The presence of animals did not significantly affect any form of K.CIextractable N. The amounts of total C in the leachates increased significantly in almost all samples when the fauna was involved. In addition, the fauna affected the humification process positively in the litter + humus and in humus alone, i.e. relatively more humic substances than total C were liberated from the materials in the presence of animals.