Table 1. Soil geochemical properties in three sites under non-planting and planting treatments^a.

Soil propertyb	Non-planting (N)c	Planting (N)	Non-planting (M)	Planting (M)	Non-planting (S)	Planting (S)
pH	6.26 ± 0.10c	6.28 ± 0.02c	7.70 ± 0.12b	8.68 ± 0.03a	5.97 ± 0.22c	5.09 ± 0.06d
SOM (g kg−1)	48.57 ± 2.94a	48.85 ± 0.81a	9.49 ± 0.32b	7.39 ± 0.40b	9.92 ± 0.41b	10.50 ± 0.40b
TN (g kg−1)	2.13 ± 0.15a	2.28 ± 0.08a	0.61 ± 0.06b	0.59 ± 0.06b	0.64 ± 0.02b	0.74 ± 0.06b
TP (g kg−1)	0.83 ± 0.02b	0.91 ± 0.02a	0.62 ± 0.02c	0.57 ± 0.02c	0.44 ± 0.00d	0.45 ± 0.02d
TK (g kg−1)	18.53 ± 0.19a	18.05 ± 0.13a	17.84 ± 0.17a	16.64 ± 0.42b	9.86 ± 0.12c	8.86 ± 0.22d
AN (mg kg−1)	161.7 ± 3.8b	206.8 ± 4.8a	41.8 ± 1.1d	35.2 ± 1.1d	52.8 ± 0.0c	57.2 ± 1.1c
AP (mg kg−1)	33.04 ± 5.82a	25.57 ± 2.12ab	6.58 ± 0.26c	2.26 ± 0.47c	21.06 ± 1.32b	20.32 ± 1.33b
AK (mg kg−1)	152.5 ± 1.4a	150.8 ± 6.0a	95.8 ± 5.1c	62.5 ± 5.2d	131.3 ± 3.6b	143.3 ± 5.8ab
NO3-N (mg kg−1)	16.69 ± 0.31a	6.98 ± 0.32b	3.50 ± 0.16d	4.15 ± 0.32d	5.29 ± 0.17c	5.24 ± 0.21c
NH4-N (mg kg−1)	0.32 ± 0.04d	0.62 ± 0.05c	0.79 ± 0.01b	0.78 ± 0.08b	1.51 ± 0.01a	1.62 ± 0.04a

^aAll data are presented with mean ± SE, and values within the same row followed by the different letter indicate a significant difference at P < 0.05.

^bAbbreviations: SOM, soil organic matter; TN, total nitrogen; TP, total phosphorus; TK, total potassium; AN, available nitrogen; AP, available phosphorus; AK, available potassium.

^cN, north site with cold temperate climate; M, middle site with warm temperate climate; S, South site with subtropical climate.