Relationship between the estimated responsiveness to applied N or response index (RI-NDVI) from sensor readings (RI-NDVI = NDVI in the N Rich strip divided by the NDVI in the farmer practice) and the response index determined at harvest (Grain yield in the N rich strip plot divided by the N Rich strip in the farmer practice), 2004 Corn Trials.  The responsiveness to N can be determined from mid-season sensor measurements collected between V8 and V9.

Relationship between INSEY (NDVI divided by the # of days from planting to sensing) collected at V8, and final corn grain yield.

Corn grain yields in the check (0 kg N/ha) and the N adequate or N rich (180 kg N/ha) plots, and the associated response index (grain yield N rich, divided by the grain yield in the check) from 1969 to 1983 in the RC-RS long-term corn experiment conducted by Professor R.A. Olson near Mead, Nebraska.

Yield level (180 lb N/ac) versus the response index (yield at 180 kg N/ha divided by yield at 0 kg N/ha), Mead, NE 1969-83

Optimum N rate (N uptake max yield minus N uptake check, divided by .5) versus yield level, 180 kg N/ha, Mead, NE, 1969-83.

N Rate, lb/ac						State			N Rate, lb/ac					60% NUE
Year	0	90	180	270	LSD	NE Avg.		RI	0	90	180	270	Added GN	N Rate	Added N
		Grain yield, bu/ac							Grain N uptake, lb/ac				Uptake	Computed	Predicted	Difference
1969	148	167	175	164	6.3	94		1.18	98	104	111	105	13	22	30	8
1970	98	127	133	140	4.3	76		1.36	65	72	81	88	16	27	39	11
1971	101	154	144	163	3.3	85		1.43	67	118	114	132	47	79	47	31
1972	67	142	152	159	9.9	104		2.27	44	89	104	113	60	100	94	6
1973	96	131	140	137	4.6	94		1.46	63	87	95	99	32	53	48	4
1974	68	108	118	118	10.3	70		1.74	45	88	96	96	51	85	55	30
1975	41	131	142	138	7.6	85		3.46	27	99	113	113	86	143	111	32
1976	96	139	135	145	6.1	85		1.41	63	98	96	112	33	54	43	11
1977	84	107	121	117	11.1	99		1.44	56	76	88	87	32	54	41	13
1978	149	181	175	181	4.2	113		1.17	98	119	114	118	16	26	29	3
1979	93	170	173	171	1.7	115		1.86	61	104	110	113	49	81	88	7
1980	61	139	144	143	6.3	85		2.36	40	82	90	86	50	83	91	9
1981	108	137	144	149	3.5	115		1.33	71	97	104	111	33	54	40	15
1982	75	145	155	165	4	110		2.07	50	88	96	102	46	77	88	11
1983	54	118	119	126	4.7	97		2.20	36	77	81	86	45	76	72	4
mean	89.3	139.7	144.7	147.7	5.9	95.1		1.620612				Mean	41	68	61	13
CV	0.34	0.15	0.13	0.13	0.47	0.15