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