Table 1.

Spearman rank correlations between soil parameters and probe-hole depths and density. W = soil gravimetric water content. MPa = Mega Pascal, * = significant at 5% level, ** = significant at 1% level

	Strength of correlation
	Probe-hole depth			Probe-hole density
Soil parameter	r	P	n	r	P	n
Penetrability (MPa)	−0.339	0.000**	126	0.014	0.441	112
W 0–50 mm	0.149	0.052	120	0.251	0.010**	85
W 50–100 mm	0.232	0.003**	136	0.160	0.048*	85
W 100–150 mm	0.245	0.003**	120	0.166	0.064	85