The multivariate analysis showed that both soil type (p= 0.0127)
and organic fertilizer (p= 0.0012) significantly affected E. coli
O157:H7 survival in fertilizer-amended soils. However, the
organic fertilizer application played a more important role in
regulating E. coli O157:H7 survival than soil type. Generally,
E. coli O157:H7 survived significantly longer in fertilizeramended soils (17.55±6.42 days,p< 0.05) than in original soils
(11.48±5.15days). Stepwise multiple regression analysis for the
20 fertilizer-amended soils displayed that soil pH and EC had a
profound influence on thetd values (Table 3), which was confirmed by hierarchical partitioning analysis (Fig. 3). Path analysis
also revealed that soil pH, EC and NO3
−
-N content had higher direct
effects than their indirect effects on thetdvalues; however, the
indirect effect (DC =−0.533) of WSOC via EC was higher than that
of the direct effect (DC = 0.433) on thetdvalues (Table 4).