Fresh and Composted Paper Sludges Sustain Soil Productivity

Table 1

Selected properties of fresh (FDS) and composted (CDS) paper sludges.

	Application Periods
Property^†	Spring 2000		Fall 2000		Fall 2001
	FDS	CDS	FDS	CDS	FDS	CDS
Dry weight (g kg^-1)	369	370	280	400	363	406
pH (H2O 1 : 1)	7.45	8.14	7.4	6.8	6.07	7.01
Organic C (g kg^-1)	344	264	334	281	335	253
Total N (g kg^-1)	8.0	7.8	11.3	7.6	7.2	5.9
C : N ratio	43	34	25	32	47	43
P (g kg^-1)	0.78	0.74	1.15	1.15	1.03	1.39
K (g kg^-1)	0.55	0.59	0.65	0.99	0.55	1.01
Ca (g kg^-1)	29.2	24.1	30.8	23.6	34.0	27.2
Mg (g kg^-1)	0.76	1.27	0.71	1.64	0.91	1.77
B (mg kg^-1)	n.d.	n.d.	7	13	2.8	7.2
Cu (mg kg^-1)	130	86	154	115	177	237
Fe (mg kg^-1)	1320	4025	1001	6704	1106	6312
Mn (mg kg^-1)	84	224	93	266	88	249
Zn (mg kg^-1)	98	315	n.d.	n.d.	124	305
Mo (mg kg^-1)	n.d.	n.d.	5	5	4.5	2.4
Cr (mg kg^-1)	23	71	12	52	11.5	11.2
Co (mg kg^-1)	1.6	2.3	1.0	2.0	3.2	33.7

^†Elements listed are expressed on dry weight basis.
n.d.=notdetected.