ABSTRACT
I. INTRODUCTION The role of protozoa in crop production has been researched since the pioneering work at Rothamsted, England, by Russell and Hutchinson (1909) on the effect of partial sterilization of “sick soils.” Sixty-eight years later, a simulation model developed by Hunt et al. (1977) reconciled a number of inconsistencies of earlier soil protozoan studies, and demonstrated that protozoan predation on bacteria enhances nutrient recycling. Microcosm and field studies since then have defined the role of protozoa in this fundamental process (Stout, 1980; Bamforth, 1985). Foissner (1987) described soil protozoa more precisely, and developed the impor tant concept of using them as bioindicators, i.e., organisms that can detect and quantify one or a complex of environmental factors. Recent research and con cepts have been collected in Soil Protozoa, edited by John Darbyshire (1994).
