A pot trial with two sampling times was conducted to compare the non-target effects of Nil endophyte ryegrass with three endophyte/ryegrass combinations, two selected endophytes (AR1 and AR37) and a wild-type, in the same cultivar. Shoot dry weight, soil nematode and microbial abundance and community diversity were assessed at each sample time. Plants infected with wildtype endophyte produced significantly less shoot weight than all other treatments due to slow initial growth. Keywords: Neotyphodium, Denaturing Gradient Gel Electrophoresis, Enrichment Index, Structure Index, Nematode Channel Ratio