Effect of Long-Term Paddy-Upland Yearly Rotations on Rice (Oryza sativa) Yield, Soil Properties, and Bacteria Community Diversity

Table 2

General soil properties before the experiment started in 2001 (0–20 cm soil depth).

Treatment	pH	SOM	TN	TP	^aAvailable K	Bulk density
		(g/kg)	(g/kg)	(g/kg)	(g/kg)	(g/cm^3)
CK	6.51	26.90	2.53	0.62	0.22	1.17
RP	6.69	24.50	2.49	0.65	0.24	1.21
RR	6.82	25.60	2.50	0.63	0.23	1.12
RC	6.62	29.10	2.46	0.66	0.23	1.24
ROM	6.43	27.50	2.69	0.61	0.22	1.11
ROF	—	—	—	—	—	—
Means	6.61	26.72	2.53	0.64	0.23	1.17
^bCV%	2.30	4.81	3.32	3.08	3.61	4.85

^aAvailable K was extracted with 1 mol NH₄AC.
^bC.V. is coefficient of variation.
Abbreviations: CK: rice-fallow phase; RR: rice-ryegrass; RP: rice-potato, with rice straw as mulch; RC: rice-Chinese milk vetch; ROM: rice-oilseed rape with burned straw return after harvest; ROF: rice-oilseed rape with fresh straw return as mulch at flowering.