Effect of humic substances and clay minerals on the hydrosorption capacity of clay particles in meadow soils (Middle Priamurje, Far East of Russia)

Chemical and Biological Technologies in Agriculture

Table 1 General characteristics of the soil profile

Horizon, depth, cm	pH_water	Exchangeable cations		C-OM	C-HA	C-FA	Fe₂O ^a₃	Particle content <0.01 mm^b
		Ca²⁺	Mg²⁺	C-OM	C-HA	C-FA	Fe₂O ^a₃	Particle content <0.01 mm^b
		cmol kg⁻¹		%
Ag 0–14	5.8	16.49	4.95	4.90	1.88	1.41	1.51	58.5
Elcg 22–30	5.9	11.96	7.42	1.00	0.22	0.26	2.19	60.8
Btg1 65–80	6.3	17.68	9.77	0.95	0.19	0.23	1.66	79.3
Cg 150–160	6.3	16.58	7.87	0.75	ND	ND	1.61	68.9

C-OM organic matter carbon, C-HA humic acid carbon, C-FA fulvic acid carbon
^aFe₂O₃, dithionite–citrate–bicarbonate extracted
^bPipette method