Aim. Al-assiuty et al., Effects of dry sludge application on soil microarthropod communities in a reclaimed desert ecosystem, PEDOBIOLOG, 44(5), 2000, pp. 567-578
The ecological impact of dried sewage sludge addition to reclaimed soil was
assessed by comparing soil microarthropod fauna (oribatid and collembolan
populations) of sewage sludge treated plots with those of adjacent control
plots. An Egyptian orchard of newly reclaimed soil cultivated with guava tr
ees (sandy soil) at El Salheya region was selected for the present investig
ation. Sludge application was performed at three doses i.e. 1.6 ton/ha, 3.3
ton/ha and 6.5 ton/ha. Four replicates were conducted for each dose applic
ation through a one-year period (during the four seasons). Sludge applicati
on had a marked influence on some soil microarthropods but no influence cou
ld be detected on others. The intensity of the effect was strongly correlat
ed to sludge doses. Also, a marked quantitative and qualitative influence c
ould be observed on soil-bound mites. It was discovered that application of
sludge up to 6.5 ton/ha over the period of a year to the reclaimed area pr
oduced a marked significant effect on the oribatid community. Scheloribates
laevigatus, Epilohmannia c. cylindrica and Isotomina thermophila may serve
as bioindicators to evaluate the role of sewage sludge application on the
soil habitat.