TABLE 1.

Soil and microbial biomass measurements as affected by interactions between plant species, SSU additions, and time^a

Parameter	pH	Microbial activity (mg TPF g−1 dry soil)	Microbial biomass (mg biomass C g−1 dry soil)	Ribotype no. (means of ribotypes)
SSU treatments	5.379	25.65	2.395	53.5
Zero SSU	6.021	22.05	2.485	61.2
Low SSU	6.275	41.68	2.532	53.5
Medium SSU	6.404	41.88	2.57	51.8
High SSU
P value	***	***	NS	NS
SED	0.0292	2.445	0.118	5.66
Plant species
Bare soil	6.031	31.44	2.508	50.8
A. capillaris	6.103	32.73	2.442	58.2
L. perenne	5.925	32.77	2.536	56.1
P value	***	NS	NS	NS
SED	0.0253	2.117	0.1022	4.9
Time
Day 35	6.462	35.46	3.767	54.4
Day 75	5.577	29.18	1.224	55.7
P value	***	***	***	NS
SED	0.0207	1.729	0.0834	4

^aP values shown as *** indicate a P value of <0.001. NS, not significant; SED, standard error of difference; TPF, triphenylformozan.