Table 1.

Statistical analysis of eight trace elements (mg·kg⁻¹) and soil properties (pH; CEC, cmol(+)·kg⁻¹; and SOM, g·kg⁻¹) in three farmland soils. The different capital letters after the Mean values indicate a significant difference (p < 0.05) in trace element content or soil properties among the three farmlands using One-way ANOVA, whereas same capital letters show no significant differences (p > 0.05). Soil properties had no background values thus “/” are used in the table below.

Farmlands	Trace elements and soil properties	Min	Max	Mean	Background value	Standard deviation (SD)	Exceedance rate (%)
Grain field N = 63	As	0.37	75.3	18.22A	11.20	20.51	46.00
	Cd	0.06	0.36	0.18A	0.12	0.08	80.95
	Cr	20.90	61.90	43.95A	39.60	7.64	79.36
	Cu	13.10	36.20	27.56B	35.80	5.09	1.58
	Hg	0.007	0.18	0.03B	0.02	0.02	80.95
	Ni	12.90	34.20	23.35A	26.40	3.99	12.70
	Pb	2.52	37.50	21.11A	13.50	6.40	90.47
	Zn	46.10	156.00	106.61A	76.80	22.73	88.89
	pH	7.61	14.20	8.31AB	/	3.17	/
	CEC	1.10	24.30	8.29B	/	4.72	/
	SOM	9.04	58.40	21.44B	/	9.13	/
Orchard N = 135	As	3.57	24.10	11.21B	11.20	4.23	40.00
	Cd	0.04	0.24	0.15B	0.12	0.03	92.60
	Cr	34.50	56.40	43.01A	39.60	5.17	72.59
	Cu	13.10	46.10	23.95C	35.80	6.69	6.67
	Hg	0.01	0.05	0.018B	0.02	0.008	62.96
	Ni	16.90	33.40	22.58A	26.40	3.33	14.81
	Pb	14.60	25.50	18.83B	13.50	2.42	100
	Zn	46.10	128.00	75.48B	76.80	22.32	38.52
	pH	7.64	13.40	8.70A	/	1.03	/
	CEC	0.40	14.60	7.17B	/	3.45	/
	SOM	9.41	43.30	23.87B	/	8.56	/
Vegetable patch n = 337	As	0.37	98.70	7.15C	11.20	9.67	13.05
	Cd	0.04	0.32	0.17A	0.12	0.05	82.49
	Cr	20.90	64.30	40.48B	39.60	8.69	55.49
	Cu	20.50	76.00	32.74A	35.80	8.17	26.11
	Hg	0.007	0.25	0.08A	0.02	0.05	96.73
	Ni	12.90	44.47	23.38A	26.40	5.20	29.37
	Pb	2.52	38.80	18.06C	13.50	3.93	93.77
	Zn	59.30	244.00	99.04A	76.80	31.41	81.90
	pH	6.80	14.30	8.91B	/	3.22	/
	CEC	0.40	29.30	15.12A	/	5.30	/
	SOM	3.68	57.45	40.94A	/	29.20	/