Applied and Environmental Soil Science

Research Article

Applying Sewage Sludge to Eucalyptus grandis Plantations: Effects on Biomass Production and Nutrient Cycling through Litterfall

Table 5

Average nutrient concentrations in leaf litter and total amounts of dry matter and nutrients returning to the soil via litterfall from 12 to 36 months after planting.


Treatment	Dry matter		N		P		K		Ca		Mg		S
	Concentrations (g kg⁻¹)

Control			10.2	a	0.4	a	0.9	b	6.1	c	1.7	b	1.4	a
Mineral fertilizer			9.5	b	0.3	a	2.3	a	8.1	a	2.8	a	1.3	a
Wet sewage			9.8	a b	0.4	a	2.1	a	6.7	b c	1.7	b	1.3	a
Dry sewage			9.3	b	0.4	a	2.0	a	7.2	b	1.7	b	1.3	a

	Annual amounts of dry matter and nutrients in litterfall
	Mg ha⁻¹ year⁻¹		kg ha⁻¹ year⁻¹

Control	4.0	b	46	a	1.6	b	3	b	24	b	6	c	7	a
Mineral fertilizer	5.2	a	54	a	1.6	b	10	a	41	a	14	a	7	a
Wet sewage	5.3	a	56	a	2.2	a	10	a	35	a	9	b	7	a
Dry sewage	5.4	a	55	a	2.3	a	10	a	37	a	9	b	6	a

Significant differences () among treatments indicated by different letters in the same column.
Nutrient concentration is an arithmetic average obtained in the analysis performed during the study (12–36 months), nutrient returned value is the sum of all periods.