. 2019 Aug 20;10:1916. doi: 10.3389/fmicb.2019.01916

TABLE 1.

Soil physicochemical characteristics and heavy metal content (mg kg^–1 dry soil) at each sampling site.

Sampling site	TD0	TD1	TD2	TD3	Background value
pH	8.00 ± 0.02^ab	7.76 ± 0.20^c	8.04 ± 0.21^a	7.80 ± 0.11^bc	–
TN (g/kg)	0.58 ± 0.03^c	0.89 ± 0.16^b	1.12 ± 0.06^a	0.89 ± 0.07^b	–
TC (g/kg)	12.28 ± 0.26^c	16.20 ± 1.27^a	13.95 ± 0.46^b	15.86 ± 1.52^a	–
TS (g/kg)	1.51 ± 0.71^a	0.73 ± 0.10^b	0.59 ± 0.02^b	0.68 ± 0.11^b	–
As	6.94 ± 2.42^b	12.28 ± 4.32^a	7.15 ± 3.44^b	10.52 ± 3.96^ab	9.1
Cd	0.17 ± 0.08^c	1.25 ± 0.66^a	0.54 ± 0.34^bc	0.76 ± 0.25^ab	0.1
Cr	47.24 ± 20.04^b	381.91 ± 176.75^a	371.90 ± 169.15^a	339.05 ± 174.71^a	55.3
Cu	338.00 ± 184.21^a	323.28 ± 157.59^a	122.10 ± 36.15^b	157.91 ± 36.37^b	22.9
Ni	34.17 ± 7.63^a	79.51 ± 55.13^a	77.89 ± 44.53^a	101.79 ± 67.16^a	29.9
Pb	756.76 ± 221.91^a	1227.24 ± 360.65^a	983.42 ± 292.03^a	1098.53 ± 349.17^a	14.7
Zn	33.43 ± 18.91^b	77.17 ± 36.37^a	89.23 ± 23.84^a	64.67 ± 16.73^ab	63.5

Data are means ± standard deviation. The different letters indicate that the means are significantly different among soils (P < 0.05) with Duncan test. TN, TC, and TS represent soil total nitrogen, soil total carbon and soil total sulfur, respectively.