Table 1.

Area-weighted mean SOC stocks (0–20 cm) and amounts of returned crop straw/stover in 2011 (N refers to the number of counties investigated; the lower and upper limits of SOC stock refer to the 95% confidence intervals of the bootstrap estimates)

Region	n	SOC stock (Mg C ha−1)			Straw/stover residue input (Mg C ha−1)
		Mean	Lower limits	Upper limits
Northeast China	8	42.20	40.68	43.76	0.39
North China	6	21.15	20.04	22.33	1.38
East China	16	30.42	29.79	31.03	0.82
Southwest China	8	34.07	32.66	35.56	0.72
South Central China	13	29.59	28.83	30.34	1.16
Northwest China	7	20.98	20.31	21.73	0.84
Whole China	58	32.90	32.34	33.47	0.89