Oakes Irrigation Research Site
Carrington Research Extension Center * North Dakota State University
P.O. Box 531, Oakes, ND 58474-0531, Phone: (701) 742-2744, FAX: (701) 742-2700, E-mail:										Kelly.c.Cooper@ndsu.edu


Strip-Till, Corn on Corn, Nitrogen Rate Study
K. Cooper, L. Besemann and H. Eslinger

Conventional grown continuous corn requires extensive tillage with high fuel use. Continuous corn requires about 40 lb more N/acre than corn grown on soybean ground. It is the objectives of this study to grow continuous corn in a strip-till system that eliminates full width tillage and to find efficient nitrogen rates.

MATERIALS AND METHODS

Soil:	Embden sandy loam and Hecla sandy loam; pH = 7.3; 2.5% organic matter; soil N average 7 lbs/acre; soil P and soil K was very high; soil S was low.
Previous crop:	2015 - field corn.
Seedbed preparation:	Strip-till May 5 with an Orthman strip-till machine.
Hybrid:	Wensman W8184VT2RIB.
Planting:	Planted April 28 in 30-inch rows @ 26,000 seeds/acre.
Plots:	Plots were 120 ft long by 20 ft (8 rows) wide. There were four replications.
Fertilizer:	All plots received 12 lbs N/acre plus 40 lbs P₂O₅/acre stream-barred as 10-34-0 and, 13 lbs N/acre plus 18 lbs S/acre stream-barred as 15-0-0-20 May 9. Stream-barred 79 lbs N/acre as 28-0-0 to the 100 and 150 lb treatments and 44 lbs N/acre as 28-0-0 to the 150d and 200 lb treatments May 20. Sidedress N treatments as 28-0-0 (three inches deep) June 16; the 150 lb treatment received 47 lbs N/acre, the 150d treatment received 83 lbs N/acre and the 200 lb treatment received 132 lbs N/acre.
Irrigation:	Hand move sprinkler irrigation as needed.
Pest control:	Roundup (40 oz/acre) + Harness (2 pt/acre) + AMS (1 lb/10 gal) + Preference (1.6 oz/gal) May 10, Laudis (3 oz/acre) + Roundup (32 oz/acre) + NIS (1 pt/100 gal) + AMS (1 lbs/10 gal) + Interlock (4 oz/acre) June 20.
Remote sensing:	Sensing was achieved with an Opti-Sciences CCM 200 Plus chlorophyll meter.
Harvest:	October 17 with a JD 4400 combine. Harvest area was the middle four rows of each plot, 120 feet long.
RESULTS
Determining nitrogen sufficiency in time is important to achieve N efficiency. Remote sensing utilized an Opti-Science CCM 200 chlorophyll meter to measure N sufficiency. Increasing nitrogen rates (N) increased grain yield and chlorophyll meter readings. Remote sensing by chlorophyll meter did well in predicting corn N status.


Table 1. Strip-till, corn on corn nitrogen rate study at the Oakes Irrigation Research Site in 2016.
		Grain			Chlorophyll
Fertilizer	Grain	Yield	Harvest	Test	Meter	Nitrate-N		Seed	Seed	Seed	Emerge	Silk
N Rate	Yield¹	2009-16	Moisture	Weight	Reading²	Stalk	Fall Soil	Protein	Starch	Oil	Date	Date
lb/acre	bu/ac		%	lb/bu	4-Aug	ppm	lbs/ac	----------%-----------

22	108.3	86.9	17.7	54.7	12.2	12	11	7.0	73.3	3.7	21-May	22-Jul
100	190.4	171.3	18.0	56.9	47.1	20	14	8.3	73.0	3.5	21-May	19-Jul
150	207.8	191.4	18.3	57.1	53.3	30	18	9.2	72.3	3.6	21-May	20-Jul
150d	208.9	199.8	18.4	57.1	54.9	198	15	9.3	72.1	3.7	22-May	20-Jul
200	218.8	210.6	17.1	57.5	58.1	352	25	9.4	72.1	3.6	21-May	19-Jul

Mean	186.8		17.9	56.6	45.1	122.3	16.6	8.6	72.5	3.6	21-May	20-Jul
C.V. (%)	1.9		1.7	1.17	5.6	135.8	19.8	6.2	0.8	5.1	0	0
LSD 0.10	4.3		0.4	0.8	3.2	209	4	0.7	0.7	0.2	NS	0.7
LSD 0.05	5.3		0.5	1.0	3.9	256	5	0.8	0.9	NS	NS	0.8

Planting Date = May 6; Harvest Date = October 24; Previous Crop = Corn
¹Yield adjusted to 15.5% moisture.
²Opti-Science CCM 200.

Oakes Irrigation Research Site									Other corn Studies
Variety trials	Crop index			Home page		Report 2016			Corn hybrid performance trial – irrigated
									Corn hybrid performance trial – dryland
									Stover removal corn/corn and corn/soybean rotation
									Strip-tilled corn N rate; corn soybean rotation