Fig. 3. Changes in the number of culturable E. coli over time in sterile soils after manure amendment. Two soil types, sandy loam and silt loam, were amended with (C) liquid swine manure and () solid beef cattle manure (8 parts fresh manure to 92 parts dry weight soil). Changes presented here were measured before stabilization of E. coli numbers (10¹ to 10² cfu 100 g^–1 dry matter content of soil–manure mixtures) at 11 to 12 wk into the treatment. These stable levels were maintained for at least the 200 d of monitoring. Bars represent one standard deviation from mean.