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 Soybean, Nitrogen Rate Study
L. Besemann and H. Eslinger

The objective of this study was to compare corn yields of a corn/soybean rotation to those in a companion corn/corn rotation and to find differences in N response and other agronomic measurements in no-till rotations, utilizing strip-till.

MATERIALS AND METHODS

Soil:	Embden loam and Gardena loam; pH = 7.1; 1.9% organic matter; Soil N average 27 lbs/acre; soil P and soil K were very high; soil S was high.
Previous crop:	2014 – soybean.
Seedbed preparation:	Strip-till April 27 with an Orthman strip-till machine.
Hybrid:	Dairyland DS9791Aa
Planting:	Planted April 28 @ 33,000 plants per acre in 30-inch rows.
Plots:	Plots were 37 ft long by 15 ft (6 rows) wide. There were four replications.
Fertilizer:	All plots received 12 lbs N/acre and 40 lbs P2O5/acre as 10-34-0 via strip-till April 27. Stream bar all plots with 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 lb treatment and 44 lbs N/acre as 28 0-0 to the 100d, 150 and 200 lb treatments May 5. Sidedress N treatments as 28 0-0 (three inches deep) June 11; 200 lb treatment received 131 lbs N/acre, the 150 lb treatment received 81 lbs N/acre and the 100d treatment received 31.5 lbs N/acre.
Irrigation:	Overhead 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:	Remote 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:	Hand harvest October 14 and October 15. Harvest area was the two center rows from each plot (72 feet of total row).
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 soybean 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	Population	Protein	Oil	Starch	Date	Date
lb/acre	bu/ac	bu/ac	%	lb/bu	4-Aug	6-Aug	ppm	lbs/ac	plants/ac	----------%-----------

22	150.1	129.4	15.7	52.0	29.7	0.2692	121	14	30963	7.2	1.9	75.4	19-May	23-Jul
100	192.0	179.9	15.6	52.9	46.4	0.3263	39	15	31846	7.6	2.0	75.0	19-May	22-Jul
100d	201.7	193.7	15.7	52.9	53.9	0.3415	108	22	30257	8.0	2.1	74.8	19-May	22-Jul
150	217.2	222.8	15.7	53.7	58.3	0.3515	270	37	32258	8.5	2.1	74.5	19-May	22-Jul
200	220.7	232.5	15.3	53.9	62.4	0.3485	985	70	30786	8.6	2.0	74.4	19-May	21-Jul

Mean	196.3		15.6	53.1	50.1	0.3274	304	32	31222	8.0	2.0	74.8	19-May	22-Jul
C.V. %	4.6		3.2	2.0	9.1	3.8	46.2	38	4.0	3.1	8.3	0.6		0
LSD 0.10	11.4		NS	NS	5.7	0.0156	177	15	NS	0.3	NS	0.5		0.8
LSD 0.05	13.9		NS	NS	7.0	0.0191	217	19	NS	0.4	NS	0.6		NS

Planting Date = April 28; Harvest Date = October 14; Previous Crop = Soybean
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 corn rotation