Table 2.

Overview of key data for the comparison of organic versus conventional farming including relative SOC change rates per year

Experiment setup (from-to)a		Duration (years)d	Depth (cm)e	Annual changef (percent)					Nh
				Total	Experiment typeg		SOC measure
					Plot	Farm	Concentration	Mass
con–con		12, 13.1	20, 20	−0.16	−0.16	–	−0.21	−0.03	14
		(3–27)	(7.5–30)	(0.45)	(0.45)		(0.64)	(0.19)
con–org	startb	18, 15.0	20, 20	3.99	3.99	–	5.24	1.07	20
		(3–27)	(7.5–30)	(2.35)	(2.35)		(3.33)	(0.56)
	conc	12.5, 21.1	15, 20	1.08	1.11	1.07	0.93	1.34	34
		(4–70)	(7.5–50)	(0.27)	(0.84)	(0.28)	(0.40)	(0.24)

^acon–con continuous conventional management with SOC measured initially, con–org change from conventional to organic practice with either (b) change rate is calculated relative to initial value or (c) change rate between organic and conventional farming is based on paired plots without reference to initial conditions

^bRelative to starting value

^cRelative to conventional system at time of sampling

^dMedian, mean (min and max)

^eMedian, mean (min and max)

^fMean carbon change rate per year (percentage of reference) relative to starting value or conventional control, 1 SE in parenthesis

^gPlot controlled field experiment, Farm comparison of adjacent farms

^hNumber of data sets for three experimental set-ups