Fall Nitrates in the top 3-ft of soil at the Arlington Research Station in 1991-2000.

ARLINGTON AGRICULTURAL RESEARCH STATION
		Year:	91	92	93	94	95	96	97	98	99	2000
Columbia County			lb/ 3 ft-acre
Corn:	CS1	Continuous Corn	48	97	102	154	179	164	115	148	87	130
	CS2	Corn after Soybeans	41	105	105	166	141	170	128	100	77	107
	CS3	Corn after Red Clover	- -1	67	83	100	145	45	129	112	83	61
	CS4	Corn after Alfalfa	- -	- -	142	164	184	94	229	121	153	189
	CS5	Corn after Alfalfa	- -	101	118	150	202	82	180	145	173	121
Soybean:	CS2	Narrow-row Soybeans	42	74	100	71	145	73	143	100	94	81
	CS3	Wide-row Soybeans	25	66	89	83	140	76	127	98	71	68
Wheat:	CS3	Wheat / Red Clover	26	48	65	48	85	38	90	76	51	57
Alfalfa:	CS4	Direct-seeded Alfalfa	32	61	80	77	117	59	114	100	75	69
	CS	Alfalfa Hay I	27	49	55	46	117	62	112	111	74	65
	CS4	Alfalfa Hay II	- -	60	69	46	105	61	141	92	69	98
	CS5	Alfalfa with Oats	- -	- -	103	67	101	65	97	81	62	65
	CS5	Alfalfa Hay	- -	- -	84	67	107	51	116	72	63	70
Pasture:	CS6	Rotational Grazing	- -	- -	91	58	98	90	100	88	62	60
Check:			26	28	-	72	108	31	209	158	50	38

^* staggered start - soil nitrates not tested until after first season in the rotation.

Estimation equations for 3^rd foot nitrate levels:

1993 - 3ft samples taken for CS1, CS2, CS4 corn, CS3 soybean, CS5 oats/alfalfa, CS6 pasture;

2ft samples taken for remaining treatments; 3^rd foot estimated using regression of 1990-1993 data

using the following formulas:                  ARS   Y= 2.81   + 0.754*2^d ft                    n =103           r² = 0.70                                                                         LAC        Y= 0.066 + 0.830*2^d ft   n = 106  r² = 0.77

1994, 1995,1996 - 3ft samples taken for reps 1 & 4, 2ft for reps 2 & 3.  Third foot estimated using regressions of data from reps 1 & 4 using the following formulas:

1994           ARS   Y= 6.72 + 0.383*2^d ft                      n = 28             r² = 0.63                                                                                  LAC       Y= 6.08 + 0.378*2^d ft  n = 28                            r² = 0.71   

1995           ARS   Y= 9.67 + 0.593*2^d ft                      n = 28             r² = 0.62                                                                                  LAC       Y= 8.49 + 0.635*2^d ft  n = 28                            r² = 0.70   

1996           ARS   Y= 3.32 + 0.153*2^d ft                      n = 24             r² = 0.60                                                                                      LAC        Y= 2.93 + 0.467*2^d ft   n = 28                            r² = 0.61

1997 ­ Used the following regression equation for third foot samples.¹

                1997           ARS   Y= 9.07 + 0.709*2^d ft                      n = 1943        r² = 0.71

1998-2000 ­ 3^rd foot samples collected for all plots.

Fall Nitrates in the top 3-ft of soil at the Lakeland Agricultural Complex: 1991-2000.

LAKELAND AGRICULTURAL COMPLEX
		Year:	91	92	93	94	95	96	97	98	99	2000
Walworth County			lb/3 ft-acre
Corn:	CS1	Continuous Corn	132	86	134	126	135	160	146	83	116	101
	CS2	Corn after Soybeans	125	78	57	80	146	80	107	73	92	87
	CS3	Corn after Red Clover	- -1	62	59	117	130	71	130	87	109	136
	CS4	Corn after Alfalfa	- -	- -	122	207	209	130	209	137	131	118
	CS5	Corn after Alfalfa	- -	81	79	178	160	102	218	109	144	155
Soybean:	CS2	Narrow-row Soybeans	76	86	98	69	120	68	167	103	109	69
	CS3	Wide-row Soybeans	34	63	69	97	125	70	137	75	101	78
	CS15	Wide-row Soybeans	-	-	-	-	-	-	-	-	128	91
Wheat:	CS3	Wheat / Red Clover	49	45	56	61	100	46	106	90	86	63
Alfalfa:	CS4	Direct-seeded Alfalfa	67	41	78	97	118	134	142	89	-	57
	CS4	Alfalfa Hay I	71	54	71	86	122	76	140	103	95	-
	CS4	Alfalfa Hay II	- -	63	59	93	128	75	152	87	96	62
	CS5	Alfalfa with Oats	- -	- -	53	75	131	63	141	85	- -	-
	CS5	Alfalfa Hay	- -	- -	78	79	143	76	108	83	97	68
	CS15	Oat/pea/forage mix	-	-	-	-	-	-	-	-	112	76
Pasture:	CS6	Rotational Grazing	- -	- -	66	111	125	103	218	146	99	69
Check:			35	29	-	78	79	40	-	72	41	76

^* staggered start - soil nitrates not tested until after first season in the rotation.

Estimation equations for 3^rd foot nitrate levels:

1993 - 3ft samples taken for CS1, CS2, CS4 corn, CS3 soybean, CS5 oats/alfalfa, CS6 pasture;

2ft samples taken for remaining treatments; 3^rd foot estimated using regression of 1990-1993 data

using the following formulas:                  LAC   Y= 0.066   + 0.830*2^d ft                 n =106           r² = 0.77                                                                           LAC        Y= 0.066 + 0.830*2^d ft   n = 106  r² = 0.77

1994, 1995,1996 - 3ft samples taken for reps 1 & 4, 2ft for reps 2 & 3.  Third foot estimated using regressions of data from reps 1 & 4 using the following formulas:

1994           LAC   Y= 6.08 + 0.378*2^d ft                      n = 28             r² = 0.71                                                                                 LAC       Y= 6.08 + 0.378*2^d ft  n = 28                            r² = 0.71   

1995           LAC   Y= 8.49 + 0.635*2^d ft                      n = 28             r² = 0.72                                                                                  LAC       Y= 8.49 + 0.635*2^d ft  n = 28                            r² = 0.70   

1996           LAC   Y= 2.93 + 0.467*2^d ft                      n = 28             r² = 0.61                                                                                     LAC        Y= 2.93 + 0.467*2^d ft   n = 28                            r² = 0.61

1997-99 ­ Used the following regression equation for third foot samples.¹

            1997-1999                    LAC   Y= 9.07 + 0.709*2^d ft                      n = 1943        r² = 0.71

2000 ­ 3^rd foot samples collected for all plots.