Table 1. Measured or calculated plant traits and allocation variables.

Variable and units	Formula
Plant height (cm)	H
Tap root depth (cm)	D
Root biomass (g)	WR
Shoot biomass (g)	WS
Total biomass (g)	W = WR+ WS
Root-to-shoot ratio	WR/ WS
Total root length (m)	L = L tap root +L first-order roots
Total root surface area (cm2)	RSA = RSA tap root +RSA 1st-order root
Number of first-order roots	RNO
Relative root weight (%)	%R = (WR/W) × 100
Relative shoot weight (%)	%S = (WS/W) × 100