The Influence of Vermicompost and Various Concentrations of Lead on the Enzymatic Activity of Sierozem Soils of Kazakhstan

Table 4

Group composition of humus in sierozem soils of Karatau nature reserve and in its fractions (depth 0–25 cm).

Ordinary sierozem from the plots		Total carbon content (Ctotal) (%)	The content of C (% on Ctotal) in			СHA/СFA
			Humic acid (HA)	Fulvic acid (FA)	Nonhydrolyzable residue
1	Soil	1.87	25.44	32.10	42.46	0.79
	Fraction ≤0.001 mm	1.55	29.87	51.00	19.13	0.59
2	Soil	2.14	30.06	37.20	32.74	0.81
	Fraction ≤0.001 mm	2.03	32.10	46.21	21.69	0.69