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 Soybean, Nitrogen Rate Study
K. Cooper, 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 = 7.4; 2.1% organic matter; Soil N average 34 lbs/acre; soil P was very high; soil K was high; soil S was low.
Previous crop:	2015 – soybean.
Seedbed preparation:	Strip-till May 5 with an Orthman strip-till machine.
Hybrid:	Wensman W8184VT2RIB
Planting:	Planted May 6 @ 26,000 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 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 lb treatment and 44 lbs N/acre as 28-0-0 to the 100d, 150 and 200 lb treatments May 20. Sidedress N treatments as 28-0-0 (three inches deep) June 16; the 100d treatment received 32 lbs N/acre, the 150 lb treatment received 81 lbs N/acre and 200 lb treatment received 131 lbs N/acre.
Irrigation:	Overhead sprinkler irrigation as needed.
Pest control:	Roundup (40 oz/acre) + Harness (2 pt/acre) + AMS (1 lb/10gal) + Preference (1.6 oz/10 gal) May 10 and Laudis (3 oz/acre) + Roundup (32 oz/acre) + NIS (1 pt/100 gal) + AMS (1 lb/10 gal) + Interlock (4 oz/acre) June 20.
Remote sensing:	Opti-Sciences CCM 200 Plus chlorophyll meter.
Harvest:	Hand harvest October 19. 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 an Opti-Science CCM 200 chlorophyll meter determine N sufficiency. Increasing nitrogen rates (N) increased grain yield and chlorophyll meter readings. Remote sensing with the chlorophyll meter did well in predicting corn N status.

Table 1. Strip-till, corn on soybean 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	Oil	Starch	Date	Date	Population
lb/acre	bu/ac	bu/ac	%	lb/bu	3-Aug	ppm	lbs/ac	----------%-----------					plants/ac

22	141.1	130.8	20.0	54.5	16.9	20	9	6.7	2.5	75.4	20-May	22-Jul	27528
100	219.6	184.8	18.7	57.3	49.7	30	10	8.8	3.3	72.9	20-May	18-Jul	27286
100d	188.1	193.0	19.5	56.2	36.6	20	10	7.6	2.8	74.3	20-May	19-Jul	27286
150	229.2	223.6	18.7	57.7	51.4	141	11	8.9	3.2	73.0	20-May	19-Jul	27286
200	233.0	232.6	18.7	57.3	53.4	200	14	9.3	3.2	72.6	20-May	19-Jul	27225

Mean	202.2		19.1	56.6	41.6	82	11	8	3.0	73.6	20-May	19-Jul	27322
C.V. %	5.4		2.3	1.2	9.7	160	45	5.5	6.2	0.7	0.0	0.0	2.1
LSD 0.10	13.6		0.6	0.9	5.1	166	NS	0.6	0.2	0.7	NS	NS	NS
LSD 0.05	16.7		0.7	1.1	6.2	NS	NS	0.7	0.3	0.8	NS	NS	NS

Planting Date = May; Harvest Date = October 19; Previous Crop = Soybean
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 corn rotation