Organic Amendments and Earthworm Addition Improve Properties of Nonacidic Mine Tailings

Table 4

Mean (±standard deviation) C/N ratio, ammonium-N, nitrate-N, potentially mineralizable N (7-day anaerobic incubation), and total nitrogen at the end of the study (week 29). Values designated by same letter (within a column) are not significantly different from each other by SNK (𝑃<0.05; 𝑛=3).

Treatment	C/N ratio	NH4^+-N (mg kg^−1)	NO3^−-N (mg kg^−1)	Mineralizable-N (mg kg^−1)	Total N (g 100 g^−1)
Treatments with 10% biosolids
T1-WO	16.1±1.1 ab	4.3±0.7 d	827±41 cde	71.2±16.8 cde	0.39±0.04 c
T1-W	17.1±0.5 a	6.0±1.9 bcd	1050±132 bcd	37.3±11.4 e	0.35±0.02 cd
T2-WO	11.0±0.3 c	4.1±0.1 d	553±293 ef	73.9±5.6 cde	0.36±0.03 cd
T2-W	10.3±0.4 c	4.3±1.5 d	740±139 de	51.0±14.6 de	0.34±0.01 cd
T3-WO	16.1±2.1 ab	1.9±0.2 e	425±406 f	65.4±14.1 cde	0.31±0.02 cd
T3-W	15.0±0.6 b	1.7±0.2 e	672±39 de	30.4±7.9 e	0.30±0.01 d
T4-WO	8.2±0.1 d	4.9±0.6 d	1043±50 bcd	102.9±10.3 bcd	0.39±0.02 c
Treatments with 20% biosolids
T5-WO	11.7±0.3 c	6.9±0.8 abc	1210±131abc	153.6±48.6 ab	0.64±0.09 ab
T5-W	11.8±1.0 c	7.9±0.8 ab	1554±156a	184.3±23.3 a	0.69±0.05 a
T6-WO	8.8±0.1 d	5.3±0.9 cd	1031±36bcd	141.7±41.8 ab	0.59±0.03 b
T6-W	8.5±0.1 d	8.0±0.5 a	1272±40ab	199.6±33.9 a	0.69±0.05 a
T7-WO	10.8±0.2 c	4.5±0.2 d	1341±72ab	144.7±25.7 ab	0.61±0.004 ab
T7-W	11.7±0.2 c	3.7±0.6 d	1011±40bcd	112.4±9.8 bc	0.58±0.02 b
T8-WO	7.3±0.1 d	8.4±1.1 a	1490±206a	157.5±22.0 ab	0.63±0.01 ab

Concentrations are expressed on an oven-dry (mass) equivalent basis.
See Table 2 for explanation of treatments.