Table 1.

P-values for single degree-of-freedom contrasts comparing the effect of pavement type and profile design on root biomass and β, the index used to measure vertical root distribution.

Contrasts	df	p_biomass	p_β
1. Control versus all other treatments	1	0.062	< 0.001^*
2. Main effect (pavement profile design)	1	0.013^*	0.002^*
3. Main effect (pavement type)	1	0.047^*	0.243
4. Interaction (pavement profile design × pavement type)	1	0.022^*	0.976

↵*P < 0.05.