Covariance Structures in Conventional and Organic Cropping Systems

Table 1

Least squares means, minimum (Min) and maximum (Max) cumulative yield, CumY, (Mg ha⁻¹), temporal yield variance, TYV, (Mg ha⁻¹)² and coefficient of variation, CV% for treatments, Trt, and Phase within treatments, Phase(Trt), in conventional (CNV) and organic (ORG) cropping systems of a long-term experiment.

System	Effect	Var	Mean	Min	Trt/Phase(Trt)	Max	Trt/Phase(Trt)
CNV	Trt	CumY	38.8^a†	32.4	4 Yr ST−N	46.7	2 Yr CT+N
	Phase(Trt)			28.1	SC (2 Yr ST−N)	53.8	WACS (4 Yr CT+N)
	Trt	TYV	7.65^a	5.1	2 Yr ST−N	11.1	2 Yr CT−N
	Phase(Trt)			4.5	CSWA (4 Yr CT−N)	11.7	SC (2 Yr CT+N)
	Trt	CV%	56.9^b	50.1	4 Yr CT+N	60.0	2 Yr CT−N
	Phase(Trt)			45.5	ACSW (4 Yr CT+N)	69.1	SC (2 Yr CT−N)
ORG	Trt	CumY	26.5^b	18.5	2 Yr ST−N	34.3	4 Yr CT+N
	Phase(Trt)			18.9	SC (2 Yr CT−N)	35.9	WACS (4 Yr CT+N)
	Trt	TYV	4.8^b	3.6	2 Yr CT−N	6.1	4 Yr ST+N
	Phase(Trt)			3.0	SC (2 Yr CT−N)	8.4	ACSW (4 Yr CT+N)
	Trt	CV%	67.2^a	53.4	4 Yr CT+N	84.5	2 Yr CT−N
	Phase(Trt)			43.6	SWAC (4 Yr CT+N)	95.4	SC (2 Yr ST−N)

†Means, within variables, followed by the same letter do not differ significantly (DMRT, P < 0.05).