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 = 7.4; 2.9% organic matter; soil N average was 17 lbs/acre; soil P and soil K were very high; soil S was very low.
Previous crop:	2016 - field corn.
Seedbed preparation:	Strip-till May 5 with an Orthman strip-till machine.
Hybrid:	Pioneer 9929 AMXT.
Planting:	Planted May 9 in 30-inch rows @ 33,000 seeds/acre.
Plots:	Plots were 120 ft long by 20 ft (8 rows) wide. There were four replications.
Fertilizer:	All plots received (via stream-bar) 10 lbs N/acre and 40 lbs P2O5/acre as 10-34-0; 15 lbs N/acre and 20 lbs S/acre as 15-0-0-20 May 22. Stream-barred 73 lbs N/acre as 28-0-0 to the 100 and 150 lb treatments and 40 lbs N/acre as 28-0-0 to the 150d and 200 lb treatments May 25. 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:	Overhead sprinkler irrigation as needed.
Pest control:	Roundup (32 oz/acre) + AMS (10 lb/100 gal) + NIS (1 pt/100 gal) + Laudis (3 oz/acre) + Attrex 9-0 (0.5 lb ai/acre) May 26.
Remote sensing:	Sensing was achieved with an Opti-Sciences CCM 200 Plus chlorophyll meter.
Harvest:	October 28 with a JD 4400 combine. Harvest area was the middle four rows of each plot, about 120 feet long. Individual plot lengths were measured and were used to calculate the yield for each plot.
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 2017.
		Grain			Chlorophyll
Fertilizer	Grain	Yield	Harvest	Test	Meter	Nitrate-N		Seed	Seed	Seed	Emerge	Silk
N Rate	Yield¹	2009-17	Moisture	Weight	Reading²	Stalk	Fall Soil	Protein	Starch	Oil	Date	Date
lb/acre	bu/ac		%	lb/bu	4-Aug	ppm	lbs/ac	----------%-----------

22	93.7	87.7	18.0	56.1	14.4	36	10	6.9	73.8	3.3	25-May	24-Jul
100	199.0	174.3	19.2	55.8	45.1	18	8	7.4	73.4	3.3	25-May	22-Jul
150	232.6	196.0	19.5	55.4	52.8	211	15	8.2	72.7	3.4	25-May	23-Jul
150d	219.2	201.9	19.4	55.7	53.7	117	13	7.9	72.9	3.3	25-May	23-Jul
200	238.1	213.6	19.2	55.8	55.5	424	21	8.5	72.5	3.3	25-May	22-Jul

Mean	196.5	--	19.0	55.7	44.3	161	13	7.8	73.0	3.3	25-May	23-Jul
C.V. (%)	2.6	--	2.1	0.9	7.9	99.3	34.8	2.5	0.6	4.6	0	0
LSD 0.10	6.4	--	0.5	0.6	4.4	202	6	0.2	0.5	NS	NS	1.1
LSD 0.05	7.8	--	0.6	0.8	5.4	247	7	0.3	0.6	NS	NS	1.3

Planting Date = May 9; Harvest Date = October 28; 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 2017			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