Factors Controlling Carbon Metabolism and Humification in Different Soil Agroecosystems

Table 1

Chemical and physical properties at T1 and T2 sampling times. For each site, different letters indicate statistically different values among the treatments ( < 0.05).

		TOC	THC	AHC	TN	WSC	Porosity
		g kg^−1	g kg^−1	g kg^−1	g kg^−1	g kg^−1	mm^3 g^−1
T1
Abanilla-Spain	S-C	5.1^b	0.81^b	0.58^b	0.72^b	82^a	192^b
	S-WOF	27.6^a	2.82^a	1.96^a	3.28^a	225^b	203^a
Alberese-Italy	I-CA	12.6^b	1.35^b	0.89^b	1.14^b	63^b	131^b
	I-BA	18.7^a	1.93^a	1.35^a	1.38^a	70^a	147^a
Puch-Germany	P-CA	20.0^a	3.09^a	1.59^a	1.79^a	128^a	204^a
	P-IT	10.3^b	2.05^c	1.13^c	0.80^c	98^b	161^b
	P-C	11.5^b	2.45^b	1.34^b	0.98^b	96^b	160^b
T2
Abanilla-Spain	S-C	5.9^b	0.91^b	0.52^b	0.75^b	76^b	198^b
	S-WOF	24.0^a	2.63^a	1.49^a	2.52^a	154^a	217^a
Alberese-Italy	I-CA	13.1^b	1.38^a	0.69^b	0.81^b	46^b	142^b
	I-BA	18.2^a	1.41^a	0.95^a	1.64^a	53^a	154^a
Puch-Germany	P-CA	17.3^a	2.56^a	1.58^a	1.53^a	75^a	210^a
	P-IT	8.0^c	2.19^c	1.08^c	0.57^c	65^b	174^b
	P-C	11.4^b	2.40^b	1.51^a	1.18^b	58^c	167^b

TOC, total organic carbon; THC, total humic carbon; AHC, active humic carbon; TN, total nitrogen; WSC, water soluble carbon.
C, control; WOF, waste organic fraction added; CA, conventional agriculture; BA, organic agriculture; IT, intensive tillage. T1, initial sampling time; T2, one year later.