The physical and chemical characterization of soils in four study areas.

Table 1: The physical and chemical characterization of soils in four study areas.

Are^a	CEC^a (cmol/kg)	TN^b (g/kg)	PN^c (mg/kg)	TK^d (g/kg)	AK^e (mg/kg)	TP^f (g/kg)	OC^g (g/kg)	pH
Pingdi	12.98 ± 2.89	0.87 ± 0.32	9.39 ± 2.25	24.74 ± 2.49	87.53 ± 6.82	0.36 ± 0.15	8.43 ± 2.84	7.40 ± 0.30
Puan	17.68 ± 2.28	1.49 ± 0.22	8.39 ± 2.27	18.34 ± 1.46	108.04 ± 22.36	0.63 ± 0.15	13.65 ± 2.62	7.68 ± 0.12
Xingwen	21.78 ± 5.09	3.50 ± 0.32	19.70 ± 2.23	3.57 ± 0.37	270.23 ± 90.12	0.05 ± 0.02	100.01 ± 7.17	6.56 ± 1.24
Gulin	14.27 ± 1.63	2.12 ± 0.20	14.68 ± 3.16	17.27 ± 2.49	261.58 ± 47.84	0.70 ± 0.18	29.18 ± 4.38	4.53 ± 0.24

^aCation exchange capacity (buffered); ^bTotal nitrogen; ^cThe sum of nitrate nitrogen and ammonium nitrogen; ^dTotal potassium; ^eAvailable potassium; ^fTotal phosphoru; ^gOrganic carbon.