16S metabarcoding, total soil DNA content, and functional bacterial genes quantification to characterize soils under long-term organic and conventional farming systems

Chemical and Biological Technologies in Agriculture

Table 3 Results of the chemical analyses on the soil samples at the beginning of the experiment

Sample	pH	Total N	Total C**	Organic C**	Olsen P
Sample	pH	g kg⁻¹ d.m	g kg⁻¹ d.m	g kg⁻¹ d.m	mg kg⁻¹ d.m
CoProB 1a	7.99	1.96	29.54	11.86	71.53
CoProB 1b	8.11	2.02	29.89	11.77	72.44
CoProB 2a	7.61	1.56	28.30	11.16	58.09
CoProB 2b	7.73	1.63	28.47	11.20	60.31
Marsilio a	7.60	3.96	31.34	10.55	39.44
Marsilio b	7.66	4.02	32.15	11.26	40.58
CA	7.78 ± 0.09 a	2.53 ± 0.47 a	29.95 ± 0.63 b	11.30 ± 0.19 b	57.07 ± 5.89 a
Canal Dei Cuori a	7.38	5.06	42.36	23.54	109.34
Canal Dei Cuori b	7.45	5.13	43.59	22.46	101.86
Le Barbarighe a	7.91	2.72	58.10	36.19	25.04
Le Barbarighe b	7.87	2.87	58.73	35.78	27.03
Terre Emerse a	7.86	3.42	37.17	17.77	26.55
Terre Emerse b	7.69	3.58	37.33	17.32	22.98
OA	7.69 ± 0.09 a	3.80 ± 0.43 a	46.21 ± 4.00 a	25.51 ± 3.46 a	52.13 ± 16.95 a

Sample	Exchangeable Ca*	Exchangeable Mg*	Exchangeable Na	Exchangeable K
Sample	mg kg⁻¹ d.m	mg kg⁻¹ d.m	mg kg⁻¹ d.m	mg kg⁻¹ d.m
CoProB 1a	1734	140.30	65.90	64.12
CoProB 1b	1703	138.68	67.78	69.31
CoProB 2a	1886	166.97	91.09	84.67
CoProB 2b	1963	178.20	99.33	82.73
Marsilio a	3834	216.92	54.72	159.73
Marsilio b	4001	224.66	60.82	137.72
CA	2520 ± 444 b	177.62 ± 15.03 b	73.27 ± 7.26 a	99.71 ± 16.08 a
Canal Dei Cuori a	7004	472.80	118.20	267.92
Canal Dei Cuori b	7153	465.11	120.96	243.19
Le Barbarighe a	5122	244.53	93.47	121.28
Le Barbarighe b	5348	238.67	91.40	135.88
Terre Emerse a	2354	171.74	17.67	70.67
Terre Emerse b	2199	183.44	16.80	72.91
OA	4863 ± 885 a	296.05 ± 55.95 a	76.42 ± 19.37 a	151.98 ± 34.56 a

All the analyses have been conducted on the dry matter (d.m.). Means with the same letter in the vertical comparison are not significantly different at the Wilcoxon Rank Sum test. *Significance level p < 0.05, **Significance level p < 0.01