Water-extractable organic matter and its fluorescence fractions in response to minimum tillage and organic farming in a Cambisol

Chemical and Biological Technologies in Agriculture

Table 1 Effects of tillage and farming practices on soil organic carbon, nitrogen, and water-extractable organic matter

Main effects	SOC (mg g⁻¹ soil)	Total N (mg g⁻¹ soil)	SOC/total N	WEOC (μg g⁻¹ soil)	WEON (μg g⁻¹ soil)	WEOC/ WEON	NO₃–N (µg g⁻¹ soil)	NH₄–N (µg g⁻¹ soil)
Organic farming	14.0	1.5	9.1	55	1.6	36.8	10.6	0.5
Integrated	11.9	1.3	8.9	62	5.0	27.4	37.9	0.6
Minimum tillage	12.7	1.4	9.0	59	3.6	32.9	25.5	0.7
Plowing	13.2	1.5	9.1	58	3.0	31.3	23.0	0.4
0–8 cm depth	15.0	1.6	9.2	65	5.3	23.3	40.3	0.7
12–25 cm	10.9	1.2	8.9	52	1.3	40.9	8.1	0.4
Probability values
Farming	<0.01	<0.01	0.05	0.09	<0.01	0.07	<0.01	NS
Tillage	0.02	0.03	NS	NS	NS	NS	0.02	0.07
Depth	<0.01	<0.01	0.01	<0.01	<0.01	0.01	<0.01	0.09
Farming × tillage	<0.01	0.01	NS	0.09	NS	NS	NS	0.06
Farming × depth	<0.01	<0.01	0.03	NS	<0.01	<0.01	<0.01	0.04
Tillage × depth	<0.01	<0.01	0.02	<0.01	NS	<0.01	<0.01	NS
CV (±%)	2	3	2	14	17	24	9	20

The results presented in the table are geometric means of all plots within each main factor treatments
CV mean coefficient of variation between replicate plots (n = 4)