Table 3.

Critical values and coefficient of determinations for each test method for obtaining 90% of maximum dry matter at two root densities; “—” denotes no significant relationship was observed.

Soil test		CaCl2 K	Colwell K	NH4OAc K	DGT K
		mg kg−1
High demand and root density	Critical value	83	151	142	10
	R2	0.73	0.53	0.51	0.59
Low demand and root density	Critical value	57	114	91	—
	R2	0.40	0.31	0.56	—