Field_Scale_Variable_Rate

Field Scale Variable Rate Trials, 2002, 2003, 2004, 2005
Resolution Trials, 3-Point Trials, 2004, 2005

3-Point Wheat Trials 2005

Table 1. Grain yield and nitrogen fertilizer applied for 2005 Wheat 3pt trial in EFAW, Lake Carl Blackwell and Tipton, OK.

Trt	Preplant N	Topdress N*	Total N Applied, lb ac^-1			Grain Yield, bu ac^-1
	lb ac^-1		EFAW	LCB	Tipton	EFAW	LCB	Tipton
1	0	0	0	0	0	28	42	14
2	120	0	120	120	120	35	58	45
3	0	NFOA	26	28	24	32	43	21
4	45	NFOA	53	61	64	34	54	32
5	0	SBNRC	40	58	40	33	49	27
6	45	SBNRC	60	80	85	35	57	40
7	45	45	101	87	-	36	56	-
8	90	0	90	90	-	35	59	-

* UAN – 28% N

Table 2. N Fertilizer, grain yield and profit for Wheat 3 pt trial in EFAW, LCB and Tipton.

		EFAW			LCB			Tipton
Trt	Preplant	Topdress	Yield	Profit	Topdress	Yield	Profit	Topdress	Yield	Profit
	lb ac^-1	lb ac^-1	bu ac^-1	$	lb ac^-1	bu ac^-1	$	lb ac^-1	bu ac^-1	$
1	0	0	28	96	0	42	147	0	14	48
2	120	0	35	87	0	58	165	0	45	123
3	0	26	32	102	28	43	142	24	21	65
4	45	8	34	103	16	54	171	19	32	90
5	0	40	33	102	58	49	153	40	27	82
6	45	15	35	104	35	57	175	40	40	113
7	45	56	36	93	42	56	167	-	-	-
8	90	0	35	94	0	59	180	-	-	-

preplant N price lb^-1 : $ 0.30
topdress N price lb^-1 : $ 0.35
price of wheat bu^-1: $ 3.50

2005 OFIT
Table 1. N fertilizer applied for Wheat OFIT 2005 across sites, OK.

Trt	Preplant N	Topdress	Topdress N Applied, lb ac^-1
	lb ac^-1	lb ac^-1	Altus	Covington	Hennessey	Lahoma	LCB	Perkins	Tipton
1	0	0	0	0	0	0	0	0	0
2	0	Flat	45	45	45	45	45	45	45
3	0	Flat	90	90	90	90	90	90	90
4	45	Flat	45	45	45	45	45	45	45
5	45	0	0	0	0	0	0	0	0
6	90	0	0	0	0	0	0	0	0
7	0	NFOA-CV	46	34	86	34	15	12	35
8	45	NFOA-CV	20	17	44	18	8	4	29
9	0	SBNRC	32	24	77	0	9	22	37
10	45	SBNRC	2	9	26	34	11	13	29
11	0	0	0	0	0	0	0	0	0
12	0	MY-NFOA	51	33	125	33	28	26	56
13	45	MY-NFOA	18	27	21	27	12	21	37

Table 2. Grain Yield for Wheat OFIT 2005 across sites, OK.

Trt	Preplant N	Topdress	Grain Yield, bu ac^-1
	lb ac^-1	lb ac^-1	Altus	Covington	Hennessey	Lahoma	LCB	Perkins	Tipton
1	0	0	30	13	43	23	40	28	15
2	0	Flat (45)	35	20	50	39	42	30	26
3	0	Flat (90)	31	24	53	49	48	35	38
4	45	Flat (45)	28	21	55	53	43	31	37
5	45	0	29	18	53	30	44	32	24
6	90	0	29	19	51	46	44	35	27
7	0	NFOA-CV	33	19	50	37	41	30	28
8	45	NFOA-CV	31	19	56	45	41	33	35
9	0	SBNRC	32	16	54	37	42	33	25
10	45	SBNRC	30	18	54	49	41	33	34
11	0	0	32	12	47	26	41	27	18
12	0	MY-NFOA	34	19	51	43	44	32	31
13	45	MY-NFOA	29	22	52	51	43	29	33

Average CV			5%	20%	13%	20%	11%	16%	17%
CV range			3-8%	15-28%	7-24%	14-26%	7-18%	10-22%	10-23%
Average RI_NDVI			1.14	1.33	1.46	1.95	1.23	1.24	1.78

Table 3. Profit earned for Wheat OFIT 2005 across sites, OK.

Trt	Preplant N	Topdress	Profit, $ ac^-1
	lb ac^-1	lb ac^-1	Altus	Covington	Hennessey	Lahoma	LCB	Perkins	Tipton
1	0	0	106	45	151	79	140	98	53
2	0	Flat	105	55	158	121	131	90	77
3	0	Flat	78	51	155	142	135	91	102
4	45	Flat	70	44	162	155	120	81	102
5	45	0	88	51	173	92	142	98	69
6	90	0	75	40	153	134	127	96	68
7	0	NFOA-CV	98	53	145	116	138	101	86
8	45	NFOA-CV	88	46	167	139	129	99	100
9	0	SBNRC	102	48	162	131	143	107	75
10	45	SBNRC	90	48	166	146	127	99	96
11	0	0	112	42	166	91	145	99	63
12	0	MY-NFOA	100	54	134	138	145	103	87
13	45	MY-NFOA	83	53	161	155	132	102	88

3-Point Wheat Trials, 2004

Method of Application and Resolution Tipton, OK 2004

Treatment	PrePlant N	Topdress N	Grain Yield	N Use Efficiency
	lb/ac	lb/ac	bu/ac	%
Check	0	0	50.5	---
Fixed Rate 1	90	0	69.8	30
Fixed Rate 2	0	90	70.3	31
Var. Rate 3 x3 ft	0	30	63.5	60
Var. Rate 6 x 12 ft	0	33	63.5	55
Var. Rate 12 x 24	0	31	60.9	47
Average check sensor CV = 17.2% with Average NDVI = 0.61 at Feekes 5

Method of Application and Resolution Chickasha, OK - 2004

Treatment	PrePlant N	Topdress N	Grain Yield	N Use Efficiency
	lb/ac	lb/ac	bu/ac	%
Check	0	0	18.1	---
Fixed Rate 1	90	0	25.2	11
Fixed Rate 2	0	90	26.5	13
Var. Rate 3 x3 ft	0	30	24.2	24
Var. Rate 6 x 12 ft	0	33	25.4	23
Var. Rate 12 x 24	0	31	26.0	27
Average check sensor CV = 12.1% with Average NDVI = 0.28 at Feekes 5

GreenSeekerTM vs Conventional Treatments Lake Carl Blackwell, Stillwater, OK 2004

Treatment	Preplant N Rate	Topdress N Rate	Total N Applied	Wheat Yield	NUE	Gross Rev.	Add. Return
	Lb/ac			Bu/ac	%	$/ac
Check	0	0	0	31.3	----	109.00
All N Pre	120	0	120	40.4	11	111.00
Var NFOA	0	22	22	40.8	60	137.00	24.00
Var. NFOA	45	8	53	40.1	23	127.00
Flat NFOA	0	30	30	38.5	34	127.00
Flat NFOA	45	14	59	40.5	22	127.00
NFOA – OSU Nitrogen Fertilizer Optimization Alogrithm
Sensor CV at F5 = 16, NDVI = 0.4
Revenue computed with wheat priced at $3.50/bu

GreenSeekerTM vs Conventional Treatments Chickasha, OK 2004

Treatment	Preplant N Rate	Topdress N Rate	Total N Applied	Wheat Yield	NUE	Gross Rev.	Add. Return
	Lb/ac			Bu/ac	%	$/ac
Check	0	0	0	22.5	----	79.00
All N Pre	120	0	120	34.7	20	107.00
Var NFOA	0	24	24	32.0	57	106.00
Var NFOA	45	11	55	35.4	32	110.00
Flat NFOA	0	26	26	27.6	28	90.00
Flat NFOA	45	12	57	39.4	42	123.00	16.00
NFOA – OSU Nitrogen Fertilizer Optimization Alogrithm
Revenue computed with wheat priced at $3.50/bu
Sensor CV at F5 = 12 and NDVI = 0.3

GreenSeekerTM vs Conventional Treatments Orlando, OK 2004

Treatment	Preplant N Rate	Topdress N Rate	Total N Applied	Wheat Yield	NUE	Gross Rev.	Add. Return
	Lb/ac			Bu/ac	%	$/ac
Check	0	0	0	49.1	----	172.00
All N Pre	120	0	120	60.5	13	181.00
Var NFOA	0	13	13	54.3	57	186.00
Var. NFOA	45	10	55	61.8	33	202.00	21.00
Flat NFOA	0	20	20	52.4	26	178.00
Flat NFOA	45	13	13	62.7	33	205.00	24.00
NFOA – OSU Nitrogen Fertilizer Optimization Alogrithm
Sensor CV at F5 = 22% and Average NDVI = 0.5
Revenue computed with wheat priced at $3.50/bu

Field Winter Demonstrations of VRT Applicator
Covington, OK, Matt Steinert Farms (February 24, 2004)
Cherokee, OK, Kenneth Failes (February 26, 2004)
Redrock, OK, Martin Williams (March 3, 2004)

Table 1. Grain yield response to N fertilizer applications using various different resolutions, Tipton, OK, 2004.

Treatment Preplant N Topdress N Method Yield Grain NUE, %
lb/ac lb/ac bu/ac N uptake
________________________________________________________________________

1                   0                   0                      -                          50.5           71.2           -
2                   90                 0                      -                          69.8           98.4           30
3                   0                   90                    -                          70.3           99.1           31
4                   0                   30                    NFOA 3x3’        63.3           89.2           60
5                   0                   33                    NFOA 6x12’      63.5           89.5           55
6                   0                   31                    NFOA 12x24’    60.9           85.9           47
________________________________________________________________________
SED                                                                                      2.8
CV from NDVI readings in the Check plots, Feekes 5: 17.2% (range: 13.6-24.2)
avg. NDVI at F5 sensing: 0.61

Table 2. Grain yield response to N fertilizer applications using various different resolutions, Chickasha, OK 2004.

Treatment      Preplant N     Topdress N      Method               Yield          Grain          NUE, %
                      lb/ac              lb/ac                                            bu/ac          N uptake
________________________________________________________________________
1                   0                   0                      -                          18.1           25.5           -
2                   90                 0                      -                          25.2           35.5           11
3                   0                   90                    -                          26.5           37.3           13
4                   0                   36                    NFOA 3x3’        24.2           34.1           24
5                   0                   45                    NFOA 6x12’      25.4           35.8           23
6                   0                   42                    NFOA 12x24’    26.0           36.7           27
________________________________________________________________________
SED                                                                                      2.3
CV from NDVI readings in the Check plots, Feekes 5: 12.1% (range: 10.1-15.7)
avg. NDVI at F5 sensing: 0.28

Assumptions, Based upon Clyde COOP Website Aug 5, 2003, Cash prices			GS = GreenSeeker
Price of wheat, $/bu	PPN cost, $/lb N	TDN cost, $/lb N
3.15	0.19	0.25


Cooperator	Preplant N, lb/ac	In-season N, lb/ac	GS N, lb/ac	Total applied N, lb/ac	Yield, bu/ac	Return, $/ac
Apache Farmer	82	34	0	116	42	108.22
Apache NRS	100	0	0	100	49	135.35
Apache GS	0	0	37	37	46	135.65
Claybaker Farmer	76	0	0	76	34	92.66
Claybaker NRS	100	0	0	100	47	129.05
Claybaker GS	0	0	37	37	48	141.95
Ivan Peck Farmer	81	0	0	81	42	116.91	Check	48	151.2
Ivan Peck NRS	100	0	0	100	44	119.60
Ivan Peck GS	0	0	38	38	52	154.30
Scheiber 0 GS	0	0	35	35	32	92.05
Scheiber 50 Farmer	109	0	0	109	44	117.89	Check	25	78.75
Scheiber 50 NRS	100	0	0	100	43	116.45
Scheiber 50 GS	50	0	8	58	43	123.95
Steve Clark Farmer	80	0	0	80	58	167.50	Check	49	154.35
Steve Clark NRS	160	0	0	160	64	171.20
Steve Clark GS	20	0	38	58	58	169.40
Steinert_C Farmer	74	0	0	74	54	156.04
Steinert_C NRS	118	0	0	118	59	163.43
Steinert_C GS	59	0	37	96	55	152.79
Steinert_P Farmer	110	0	0	110	63	177.55	Check	58	182.7
Steinert_P NRS	183	0	0	183	63	163.68
Steinert_P GS	60	0	23	83	63	181.30

Average Data	PPN, lb/ac	TDN, lb/ac	GSN, lb/ac	Total applied N, lb/ac	Yield, bu/ac	Return, $/ac
Average Farmer	87.43	4.86	0.00	92.29	48.14	133.82
Average NRS	123.00	0.00	0.00	123.00	52.71	142.68
Average GS	19.86	0.00	35.00	54.86	50.57	146.78

Field Scale Variable Rate Trials, 2002

Average over 10 Locations

Average over 10 sites
			RI_HARVEST = 1.31
		Preplant	Early	Late	Total N	Yield	Net Revenue
n=	Treatment	N rate, lb/ac	Topdress N	Topdress N	rate, lb/ac	bu/ac	$/ac

33	2XS	62	32	0	94	44.6	116
81	VRT	41	15	23	79	39.8	104
24	VS3	35	21	35	91	37.3	93
25	VS2	49	9	24	82	35.4	91
17	Farmer Check	52	21	20	92	34.6	86
SED						3.1	9.5


***10 loc's
81	VRT	41	15	23	79	39.8	104
17	Farmer Check	52	21	20	92	34.6	86

***5 loc's
52	VRT	55	13	17	85	39.8	104
25	VS2	49	9	24	82	35.4	91

***5 loc's
48	VRT	43	24	24	91	39.2	99
23	VS3	35	21	35	91	37.9	95

***8 loc's
33	VRT	42	18	23	84	41.2	107
71	2XS	62	32	0	94	44.7	117

Net revenue = (grain yield * $3.00/bu) - (preplant N applied * $0.15/lb N)-(topdress N applied * $0.25/lb N)

SED = standard error of the difference between two equally replicated means

*** Means for only those sites where both treatments were evaluated (not all treatments were evaluated at each site)

By - Site Grain Yields

Cherokee, OK, Kenneth Failes			RI _NDVI = 1.1	Harvest Date, June 4, 2002
CV = 16			RI _Harvest= 1.24
Treatment	Description	Preplant N	Topdress N	Total N Rate	Yield
		lb/ac	lb/ac	lb/ac	bu/ac

1	Flat NFOA	30	25	55	34
2	2X Strip	60	0	60	51
3	Flat NFOA	30	23	53	37
4	VRT	30	20	50	44
5	Check	30	0	30	41
6	2X Strip	60	0	60	42
7	75 Flat	30	75	105	43
8	VRT	30	20	50	30

Amorita, OK, Steve Clark			RI _NDVI= 1.46	Harvest Date: June 12, 2002
CV = 18
			RI _Harvest = 1.36
		Preplant	Topdress	Total N	Yield
Reps	Treatment	N rate, lb/ac	N rate, lb/ac	rate, lb/ac	bu/ac

2	2X Strip	92	0	92	57.4
1	Check	46	0	46	42.2
2	Flat NFOA-45	46	45	91	44.7
3	VRT	46	41	87	49.2
1	Flat NFOA-75	46	75	121	50.2
1	Farmer	46	30	76	40.3

Earl Marshall, Hennessey			RI_SV = 1.55	Harvest Date: June 18, 2002
CV = 20		Preplant	Topdress	Total N	Yield
Reps	Treatment	N rate, lb/ac	N rate, lb/ac	rate, lb/ac	bu/ac

4	VRT	75	31	106	29.9
4	FLAT NFOA	75	25	100	26.3
4	VRT	75	35	110	28.2
4	FLAT NFOA	75	28	103	23.1

			RI_NDVI = 1.57
Matt Steinert - Emerson			RI_HARVEST=1.1		Harvest Date: June 19, 2002
CV = 26
		Preplant	Topdress	Topdress	Total N	Yield
Reps	Treatment	N rate, lb/ac	N rate, lb/ac	N rate lb/ac	rate, lb/ac	bu/ac
			Jan 12	April 3
4	2X Strip	10	100	0	110	29
4	Check	10	0	0	10	26
4	Flat NFOA	10	50	37	97	37
4	75 Flat	10	50	62	122	38
4	VRT	10	50	38	98	38
4	Flat NFOA	10	50	34	94	36
4	VRT	10	50	45	105	42

Average of Flat NFOA		36.5
Average of VRT		40.0

			RI_NDVI = 1.27
Matt Steinert - Peters			RI_HARVEST=1.34		Harvest Date: June 19, 2002
CV=18
		Preplant	Topdress	Topdress	Total N	Yield
Reps	Treatment	N rate, lb/ac	N rate, lb/ac	N rate lb/ac	rate, lb/ac	bu/ac
			Jan 12	April 3
4	2X Strip	10	100	0	110	44.8
4	Check	10	0	0	10	33.3
4	Check	10	50		60	34.2
4	Flat NFOA	10	0	21	31	34.6
4	Flat NFOA	10	50	57	117	44
4	VRT	10	50	14	74	42.8

			RI_NDVI = 1.43
Matt Steinert - Beopple			RI_HARVEST=1.24		Harvest Date: June 20, 2002
CV = 21
		Preplant	Topdress	Topdress	Total N	Yield
Reps	Treatment	N rate, lb/ac	N rate, lb/ac	N rate lb/ac	rate, lb/ac	bu/ac
			Jan 12	March 28
4	2X Strip + VRT	10	60	39	109	47.8
4	2X Strip	10	60	0	70	53.5
4	4X Strip + VRT	10	120	0	130	46.8
4	4X Strip + VRT	10	120	43	173	47.6
4	Check	10	0	0	10	43.2
4	Check + VRT	10	0	31	41	49.4
4	Flat NFOA 63	10	30	23	63	48.1
4	Flat NFOA 91	10	30	51	91	48.7
4	VRT 72	10	30	32	72	46.9

Stan Claybaker			RI_NDVI= 1.1	Harvest Date: June 24, 2002
			RI_HARVEST= 1.1
CV = 15
		Preplant	Topdress	Total N	Yield
	Treatment	N rate, lb/ac	N rate, lb/ac	rate, lb/ac	bu/ac
			11-Apr-02
4	VRT	56	10	66	43.3
4	VRT	56	10	66	42.3
4	VS1	56	9	65	40.7
4	VRT	56	11	67	41.9
4	VS2	56	23	79	40.5
4	VS5	56	54	110	42
4	2XStrip	106	0	106	44.2
4	2XStrip+VS5	106	55	161	44.2

Tom Cannon			RI_NDVI = 1.33	Harvest Date: June 24, 2002
			RI_HARVEST = 1.1
CV = 13
		Preplant	Topdress	Total N	Yield
	Treatment	N rate, lb/ac	N rate, lb/ac	rate, lb/ac	bu/ac
			11-Apr-02
4	OPTICROP	15	60, 40	115	39.1
4	Check	45	0	45	36.8
4	VRT	45	43	88	37.5
4	VS3	45	31	76	37.5
4	VRT	45	35	80	38.9
4	VS3	45	30	75	38.8
4	2XS VRT	85	40	125	38.8
4	2XS	85	0	85	38.3

Otto Matusek				RI_NDVI = 1.1	Harvest Date: June 25, 2002
				RI_HARVEST = 1.3
CV=47
		Preplant	Topdress	Topdress	Total N	Yield
	Treatment	N rate, lb/ac	N rate, lb/ac	N rate, lb/ac	rate, lb/ac	bu/ac
			10-Dec-02	3-Apr-02
4	2XS	150	28	0	178	48.64
4	VS3	75	28	36	139	39.8
4	VRT RI 1.5	75	28	13	116	44.5
4	VS1	75	28	11	114	37.2
4	VRT RI 1.1	75	28	3	106	39.1
4	VS2	75	28	25	128	40.2
4	VRT RI 1.3	75	28	11	114	40.7
4	VRT RI 1.1	75	28	4	107	38.8
4	VRT RI 1.3	75	28	8	111	40.7
4	VS1	75	28	12	115	36.7
4	check	75	28	0	103	37.1

Efaw Exp. Station			RI_NDVI = 1.65	Harvest Date: June 26, 2002
			RI_HARVEST = 1.27
CV = 35
		Preplant	Topdress	Total N	Yield
	Treatment	N rate, lb/ac	N rate, lb/ac	rate, lb/ac	bu/ac
			27-Mar-02
6	VRT	0	21	21	31.7
2	VS3	0	44	44	31.7
4	VS5	0	62	62	31.1
4	check	0	0	0	24.5