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:										Blaine.Schatz@ndsu.edu
										Leonard.Besemann@ndsu.edu

Strip-Till, Corn on Corn, Nitrogen Rate Study
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; 2.2% organic matter; soil N average 19 lbs/acre; soil P and soil K were very high; soil S was medium.
Previous crop:	2014 - field corn.
Seedbed preparation:	Strip-till April 24 with an Orthman strip-till machine.
Hybrid:	Dairyland DS9791RAa.
Planting:	Planted April 28 in 30-inch rows @ 33,000 seeds/acre.
Plots:	Plots were 140 ft long by 20 ft (8 rows) wide. There were four replications.
Fertilizer:	All plots received 12 lbs N/acre and 40 lbs P2O5/acre as 10-34-0 via April 24. Stream bar all plots 13 lbs N/acre and 17.6 lbs S/acre as 15 0-0-20 May 7. Stream bar 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 5. Sidedress N treatments as 28 0-0 (three inches deep) June 11; the 150 lb treatment received 77 lbs N/acre, the 150d treatment received 81 lbs N/acre and the 200 lb treatment received 131 lbs N/acre.
Irrigation:	Hand move sprinkler irrigation as needed.
Pest control:	Harness (2 pt/acre) May 8, Laudis (3 oz/acre) + AAtrex 9-O (0.5 lb ai/acre) + Destiny (0.05%v/v) + AMS (1½ lbs/acre) + Interlock (4 oz/acre) June 4.
Remote sensing:	Sensing was achieved with an Opti-Sciences CCM 200 Plus chlorophyll meter and a Holland Crop Circle ACS active canopy sensor (normalized difference red edge NDRE).
Harvest:	October 14 with a JD 4400 combine. Harvest area was the middle four rows of each plot, 137 feet long.
RESULTS
Determining nitrogen sufficiency in time is important to achieve N efficiency. Remote sensing utilized a Holland Crop Circle ACS 430 active canopy sensor (normalized difference red edge – NDRE) and an Opti-Science CCM 200 chlorophyll meter were tested to determine ability to measure N sufficiency. Increasing nitrogen rates (N) increased grain yield, chlorophyll meter readings and normalized difference red edge (NDRE). Remote sensing by chlorophyll meter and the Crop Circle Sensor did well in predicting corn N status.


Table 1. Strip-till, corn on corn nitrogen rate study at the Oakes Irrigation Research Site in 2015.
		Grain			Chlorophyll
Fertilizer	Grain	Yield	Harvest	Test	Meter		Nitrate-N		Seed	Seed	Seed	Emerge	Silk
N Rate	Yield¹	2009-15	Moisture	Weight	Reading²	NDRE³	Stalk	Fall Soil	Protein	Starch	Oil	Date	Date
lb/acre	bu/ac		%	lb/bu	4-Aug	5-Aug	ppm	lbs/ac	----------%-----------

22	86.6	83.8	13.0	54.4	11.1	0.1558	38	12	6.9	74.5	2.9	18-May	24-Jul
100	156.6	168.5	14.2	55.6	38.4	0.2678	43	22	7.8	74.3	2.7	18-May	23-Jul
150	183.0	189.0	14.4	56.8	53.6	0.2974	402	24	8.7	73.8	2.7	19-May	23-Jul
150d	175.2	198.5	14.6	55.9	48.7	0.2810	41	20	8.5	73.9	2.7	20-May	24-Jul
200	190.3	209.4	14.1	56.1	54.0	0.3021	985	61	9.1	73.5	2.7	20-May	23-Jul

Mean	158.3		14.1	55.7	41.2	0.2608	302	28	8.2	74.0	2.7	19-May	24-Jul
C.V. (%)	6.4		1.3	0.7	6.3	5.8	77.8	28.3	2.3	0.5	7.0	0	0
LSD 0.10	12.7		0.2	0.5	3.3	0.0190	296	10	0.2	0.5	NS	0.7	NS
LSD 0.05	15.5		0.3	0.6	4.0	0.0232	362	12	0.3	0.6	NS	0.9	NS

Planting Date = April 28; Harvest Date = October 14; Previous Crop = Corn
¹Yield adjusted to 15.5% moisture.
²Opti-Science CCM 200.
³Holland Crop Circle ACS active canopy sensor (normalized difference red edge) - NDRE.

Oakes Irrigation Research Site									Other corn Studies
Variety trials	Crop index			Home page		Report 2015			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