. 2014 Nov 11;5:631. doi: 10.3389/fpls.2014.00631

Table 5.

Concentrations of exchangeable cations in non-planted soils (n = 3) with or without 50 mg Na/kg at two K levels (40, 100 mg K/kg) after 1 week of incubation.

	Soil treatment
Measured parameters	K 40	K 40	K 100	K 100
	Nil Na	50 Na	Nil Na	50 Na
Colwell K (mg/kg)	48.3^b	51.0^b	96.0^a	102.7^a
Exchange K (cmol/kg)	0.13^a	0.14^a	0.24^b	0.27^b
Exchange Na (cmol/kg)	0.02^b	0.19^a	0.02^b	0.18^a
Exchange Ca (cmol/kg)	0.68^a	0.71^a	0.44^b	0.61^ab
Exchange Mg (cmol/kg)	0.09^a	0.10^a	0.10^a	0.10^a
Exchange Al (cmol/kg)	0.02^a	0.03^a	0.03^a	0.03^a

Means with different letters differ at P ≤ 0.05.