Table 1.

Substrate matric potential (ψ_m) at eight substrate volumetric water content treatments (θ_t) recorded on 11 January 2021.

θt (m3·m−3)	ψmz (MPa)
0.40	−0.08 ay
0.35	−0.03 a
0.30	−0.04 a
0.25	−0.23 ab
0.20	−0.26 ab
0.15	−0.56 bc
0.10	−0.51 b
0.05	−0.89 c
Linear	NSx
Quadratic	*
Cubic	****

^zψ_m was calculated from measurements of a handheld soil moisture sensor (Hydro Sense; Campbell Scientific) using a substrate-specific water retention curve estimated using the van Genuchten equation (van Genuchten, 1980), of which the residual water content is 0, the saturated water content is 0.74 m³·m⁻³, the inverse of the air entry suction is 771.43 MPa⁻¹, and the dimensionless pore-size distribution is 1.33.

^yMeans with same lowercase letters are not significantly different among treatments by Tukey–Kramer method with a significance level specified at 0.05.

^xNS, *, **** Nonsignificant, significant at p ≤ 0.05 or 0.0001, respectively.