Nitrogen Immobilization in Plant Growth Substrates: Clean Chip Residual, Pine Bark, and Peatmoss

Table 3

Chemical properties of clean chip residual, pine bark, and peatmoss substrates.

Substrate^z	pH	EC (mS·cm^−1)^y	Substrate micronutrient content^x
			B (ppm)	Fe (ppm)	Mn (ppm)	Cu (ppm)	Zn (ppm)
0.48 cm CCR	5.0 b^w	0.21 b	0.23 a	3.7 a	2.3 a	0.01 b	0.28 a
0.95 cm CCR	5.5 a	0.15 c	0.17 b	2.1 b	0.6 b	0.02 ab	0.06 c
PB	4.1 d	0.23 b	0.16 b	1.3 c	1.0 b	0.03 a	0.16 b
PM	4.8 c	0.29 a	0.13 c	0.2 d	0.2 c	0.01 b	0.05 c
	Substrate macronutrient content
	NO3-N (ppm)	NH4-N (ppm)	P (ppm)	K (ppm)	Ca (ppm)	Mg (ppm)	SO4 (ppm)
0.48 cm CCR	0.1 b	0.2 b	4.1 a	84.6 a	9.1 c	7.0 c	15.8 c
0.95 cm CCR	0.2 b	0.4 a	1.4 b	48.2 b	5.3 d	2.6 d	7.7 d
PB	0.1 b	0.1 b	4.0 a	52.5 b	16.2 b	11.5 b	50.9 a
PM	39.0 a	0.1 a	1.6 b	6.9 c	27.7 a	28.3 a	29.5 b

^zCCR:  clean chip residual, PB:  pine bark, PM:  sphagnum peatmoss.
^y1 mS·cm⁻¹  =  1 mmho/cm.
^xSubstrate analysis performed on nonamended samples; N:  nitrogen, P:  phosphorous, K:  potassium, Ca:  calcium, Mg:  magnesium, S:  sulfur, B:  boron, Fe:  iron, Mn:  manganese, Cu:  copper, Zn:  zinc, and 1 ppm  =  1 mg·kg⁻¹.
^wMeans within column followed by the same letter are not significantly different based on Waller-Duncan 𝑘 ratio 𝑡-tests (𝛼  =  0.05, 𝑛  =  3).