Table 1 Descriptive statistics of the variables included in the study

From: Limiting grazing periods combined with proper housing can reduce nutrient losses from dairy systems

Variable	System	N	N*	Median	Mean	s.e.m.	CV	Min	Max
Farm size (ha)	Grazed	75	0	30	401^a	100	217	<1	4,100
	Hybrid	46	3	64	248^a	153	418	1	6,900
	Confined	25	7	223	713^b	222	155	39	3,739
Stocking rate (cows ha⁻¹ yr⁻¹)	Grazed	59	16	3	2.9^a	0.1	33	1.0	5
Stocking rate (cows ha⁻¹ yr⁻¹)	Hybrid	40	9	1.9	1.9^b	0.1	35	0.8	3.8
	Confined	25	7	2	3.3^ab	0.8	123	0.6	17.5
N input fertilizer (kg ha⁻¹ yr⁻¹)	Grazed	57	18	170	190^b	17	69	0	684
	Hybrid	27	22	150	145^ab	14	50	4	250
	Confined	18	14	93	116^a	20	73	16	280
Total N input (kg ha⁻¹ yr⁻¹)	Grazed	58	17	170	200^a	18	69	-	684
	Hybrid	31	18	170	174^a	18	58	20	465
	Confined	19	13	169	272^a	79	127	16	1,180
N surplus (kg ha⁻¹ yr⁻¹)	Grazed	16	59	311	261^a	28	42	−20	372
N surplus (kg ha⁻¹ yr⁻¹)	Hybrid	22	27	132	155^b	20	59	7	385
	Confined	3	30	455	412^ab	248	85	164	660
N loss (kg ha⁻¹ yr⁻¹)	Grazed	63	12	35	44^a	4	78	4	175
	Hybrid	32	17	31	41^a	6	101	9	237
	Confined	24	8	42	106^a	29	136	7	486
N loss (g kg⁻¹ FPCM yr⁻¹)	Grazed	29	46	2.91	3.05^a	0.29	51	0.67	6.87
N loss (g kg⁻¹ FPCM yr⁻¹)	Hybrid	18	31	2.70	4.17^a	0.77	78	1.24	12.37
	Confined	4	28	0.94	0.92^b	0.24	52	0.39	1.4
P input fertilizer (kg ha⁻¹ yr⁻¹)	Grazed	30	45	37	39^b	3	44	5	68
P input fertilizer (kg ha⁻¹ yr⁻¹)	Hybrid	14	35	14	27^b	7	101	5	90
	Confined	4	28	12	12^a	5	77	1	24
Total P input (kg ha⁻¹ yr⁻¹)	Grazed	29	46	40	42^b	3	36	15	68
Total P input (kg ha⁻¹ yr⁻¹)	Hybrid	15	34	15	34^b	8	91	5	92
	Confined	6	26	18	18^a	3	34	10	25
P surplus (kg ha⁻¹ yr⁻¹)	Grazed	2	73	9.2	9.2^a	6.8	104	2.4	16
	Hybrid	16	33	3.4	10.1^a	4.4	173	−7.0	53.7
	Confined	8	24	1.5	2.8^a	1.3	129	−0.5	11
P loss (kg ha⁻¹ yr⁻¹)	Grazed	26	49	1.11	1.4^a	0.4	139	0.01	10
	Hybrid	26	23	1.21	4.3^a	2	242	0.02	50
	Confined	22	10	0.60	20.2^a	12.9	298	0.01	239
P loss (g kg⁻¹ FPCM yr⁻¹)	Grazed	7	68	0.09	0.09^a	0.02	71	0.01	0.17
P loss (g kg⁻¹ FPCM yr⁻¹)	Hybrid	10	39	0.12	0.11^a	0.03	84	0.01	0.21
	Confined	5	27	0.14	0.37^a	0.22	134	0.03	1.2

For each, we include the number of data points present (N) and missing (N*), mean, standard error of the mean (s.e.m.), coefficient of variation (CV), minimum (Min), median and maximum (Max) for stocking rate, and N and P inputs (fertilizer or fertilizer plus manure = total), surplus and loss in runoff and leaching by each system. All units are in kg (N or P) ha⁻¹ yr⁻¹ except stocking rate, which was recorded as across the farm. Means for dairy systems within a variable followed by the same letter are not different from one another (in log space) using Tukey’s honestly significant difference at the P < 0.05 level.

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Table 1 Descriptive statistics of the variables included in the study

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