Tillage Effects on Spatiotemporal Variability of Particulate Organic Matter

Table 2

Descriptive statistics for soil particulate organic matter (POM)-C and -N fractions, and C to N ratio in the 0–15 cm depth.

			POM-C (g C m^-2)				POM-N (g N m^-2)				C to N ratio
Fraction	Field	Time	Aug. 03	Apr. 04	Oct. 04	June 05	Aug. 03	Apr. 04	Oct. 04	June 05	Aug. 03	Apr. 04	Oct. 04	June 05
>1000  𝜇m	North	Mean	14.8	11.3	20.2	9.5	0.74	0.37	0.60	0.48	21.2	32.8	35.4	21.2
		Minimum	4.0	3.1	3.2	3.1	0.13	0.12	0.20	0.20	9.3	15.3	11.0	9.0
		Maximum	41.2	41.7	55.8	17.0	2.27	1.23	1.57	1.19	33.2	74.0	95.3	57.4
		CV^†	55	69	65	44	62	68	45	50	23	40	71	42
	South	Mean	15.9	21.2	25.4	23.8	0.76	1.02	1.19	1.35	19.5	21.1	20.3	18.4
		Minimum	3.0	3.8	3.9	7.5	0.12	0.17	0.21	0.57	7.5	11.1	9.3	7.3
		Maximum	49.1	54.5	56.9	46.1	2.75	2.18	2.15	3.05	33.8	34.9	31.0	32.5
		CV	72	58	53	49	68	52	41	44	32	27	28	33
250–1000 𝜇m	North	Mean	85.0	54.7	54.8	53.1	4.63	2.26	2.68	2.90	18.8	24.8	20.7	19.0
		Minimum	47.4	27.9	25.4	30.8	2.62	1.04	1.52	1.76	15.3	15.6	15.3	15.5
		Maximum	155.2	91.6	80.6	81.1	7.84	5.49	4.00	5.13	23.1	32.2	36.5	22.9
		CV	33	30	25	20	32	37	22	26	9	13	23	11
	South	Mean	82.0	89.8	83.2	98.6	3.97	4.09	4.25	5.30	21.5	22.1	19.7	18.4
		Minimum	45.3	36.3	40.5	47.3	1.76	1.55	1.97	3.02	14.0	16.1	14.1	11.9
		Maximum	164.5	186.6	131.7	179.1	7.14	7.85	6.69	8.51	30.3	31.0	27.1	23.9
		CV	32	39	27	34	36	35	24	28	21	16	16	14
53–250 𝜇m	North	Mean	157.8	118.4	117.7	105.9	10.55	6.64	7.36	7.94	15.1	18.1	15.8	13.3
		Minimum	120.8	87.0	76.5	72.7	7.21	4.30	5.22	5.65	12.5	13.7	13.1	11.9
		Maximum	200.1	150.1	155.1	136.0	15.06	10.94	9.22	10.52	19.4	22.7	20.4	14.2
		CV	13	14	14	15	17	21	14	13	11	10	10	4
	South	Mean	137.8	144.6	139.6	149.1	9.87	8.77	8.59	10.90	14.4	16.8	16.2	13.6
		Minimum	81.0	87.6	92.2	95.4	6.11	5.17	5.36	7.36	11.0	14.3	12.5	10.9
		Maximum	227.0	211.4	235.1	231.3	16.73	12.90	11.56	15.16	22.5	21.0	20.7	15.6
		CV	25	20	23	21	31	20	17	17	19	11	12	8

^†CV: coefficient of variation.