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Effects of Narrow Row Spacing on Corn Silage Yield and Growth. Brian Jones Agronomy Extension Agent. Introduction. Interest in narrow row corn production increasing…for good reason
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Effects of Narrow Row Spacing on Corn Silage Yield and Growth Brian Jones Agronomy Extension Agent
Introduction • Interest in narrow row corn production increasing…for good reason • Consistently yield 4-9% more than conventional (Roth, 1996; Cox et al., 1998; Cox and Cherney, 2001; Cox and Cherney, 2002; Widdicombe and Thelen, 2002) • Economic advantage (Hallman and Lowenberg-DeBoer, 1999; Cox et al., 1998) • Greater DM and milk yields (Cox and Cherney, 2001) • Greater N use efficiency (Cox and Cherney, 2002)
Introduction • Most work has been done in grain • 6.5% yield increase under irrigation (Karlen and Camp, 1985) • Summary of studies in Corn Belt showed yield advantage (Finck, 2003, 2004, 2005) • Shown to have economic advantage in northern Corn Belt (Hallman and Lowenberger-DeBoer, 1999)
Introduction – Narrow Row Effects On: • Silage Quality • Narrow rows had greater DM yield than conventional and no affect on IVTD (Cox et al., 2006) • Narrow row system did not impact forage quality (Widdicombe and Thelen, 2002) • Hybrid choice had more to do with forage quality (Dwyer et al., 1998)
Introduction – Narrow Row Effects On: • Plant density • Optimum plant densities for silage yields the same between narrow and conventional (Cox et al., 1998; Cox et al., 2006) • Increasing densities lead to decreasing quality (Cox et al., 1998; Widdicombe and Thelen, 2002) • Hybrid choice (forage-specific) may withstand higher populations (Tollenaar, 1989)
Introduction – Narrow Row Effects On: • Nitrogen Use Efficiency • Not necessary to increase N rates or plant population with narrow row corn (Cox and Cherney, 2001; Cox and Cherney, 2002) • N accumulation linear for narrow vs. quadratic for conventional (Cox and Cherney, 2001) • Greater grain yield response to narrow rows under N deficient conditions (Barbieri et al., 2000)
Objective • To examine the effects of narrow row spacing on corn silage yield and growth characteristics under Shenandoah Valley conditions.
Methods • Two year study conducted at Cave View Farms, Inc. in Weyers Cave • Strip plot design • Twin rows (7.5” on 30” centers) • Conventional (30”) • 2006 • 6 replications under irrigation • 2007 • 3 replications under irrigation • 3 replications with no irrigation • Each plot was 12 rows by 1000’
Methods • Planting Dates: • May 2, 2006 • May 11, 2007 • Twin Rows (7.5”) • Great Plains GP1520 Precision Seeder with coulter unit • Single Rows (30”) • Great Plains 6030
Methods • Hybrid Information • 2006 Irr: Pioneer 31R87 • 2007 Irr: Pioneer 31R87 • 2007 Non-Irr: Pioneer 31G71 • Seed Drop: • 31,400 (TR) • 31,300 (SR)
Data Collection • Stand counts • 2006 • May 23; V2 Stage (21 DAP) • June 23; V8 Stage (52 DAP) • 2007 • July 11; V9 Stage (61 DAP) • Plant height to whorl (2006) • Insect and disease ratings
Harvest • Harvested 9/15/06 and 9/18/07 • Six center rows from each plot • Entire length of plot; weighed on scales (+/- 10 lbs) • Sub-sampled for quality analysis
Results: Plant Stand Counts • Stands equal between planters in both years • Achieved 90% of target with both units a a a a a a
Consistent Plant Spacing • Picket-Fence Stands!! • EXTREMELY IMPORTANT • We will discuss this later
Results: Plant Height • No significant difference in plant height in 2006 at V8 • Looking over field, TR appeared taller 2006 a a
7.5” Twin Row 30” Single Row
Results: Pest pressure • No difference in insect pest pressure between the treatments • Visible weed pressure observed in the single rows
7.5” Twin Rows 7.5” Twin Rows 30” Single Rows
PRE (4/25): 1.5 qt Lumax; 1.125 qt Aatrex; 1.5 qt Princep; 1.5 pt Gramoxone Inteon; 5.8 oz Asana • POST (6/5): 1.5 qt Prowl H2O; 0.75 qt Roundup O-Max • Difference in canopy development
Water Use Efficiency 30” Single Rows 7.5” Twin Rows
Results: Silage yield (35% DM) 18.9% 24.6 8.9% 11.8% 21.9 21.4 20.7 20.2 19.1
Results: Silage yield (35% DM) p<0.10 a b
1 site, 1 year Small plots Greater variability We will repeat this on a larger scale Effects of Increasing Population
Importance of Evenly Spaced Corn Plants Or…Why It Pays to Calibrate Your Corn Planter
Sources of non-uniform spacing • Will always leadto lower yields. • Yield effect lesswell known. • Some argue crowdingwill cause barren plants • Some suggest will haveno effect? Crop Insights Vol 12, No.2
Calibration affects yield • Study showed yield improvement of 4.2 bu/A from calibrating alone (Doerge and Hall, 2000) • Some locations exceeded 20 bu • Yield losses from 7 to 15 bu/A observed in Indiana (Nielsen, 1997) • Study from Pioneer (2001) improved plant spacing was 3.4 bu/A
Calibration affects yield • Yield increase needed to offset cost of planter meter calibration for a 600 acre grower was 0.5 bu/A (Doerge and Hall, 2000) • VERY INEXPENSIVE WAY TO MANAGE RISK • Measuring stand uniformity important
Measuring uniformity using SD • SD (standard deviation) common statistical tool, better than just looking at the average • Use spreadsheet to calculate
Measuring uniformity using SD • Example: 7” 7” Average = 7” SD = 0
Measuring uniformity using SD • Example: 8” 6” Average = 7” SD = 1
Measuring uniformity using SD • Example: 12” 2” Average = 7” SD = 5 THE SMALLER THE SD THE MORE UNIFORM THE STAND
32”…etc 9” 20” Measuring uniformity using SD • Step 1: lay 20’ tape next to a row • Step 2: record the location of each plant • Step 3: collect and record from at least 4 locations 12 24 36 48 60 72 tape measure
Measuring uniformity using SD 2-0 = 2 17-2 = 15 Average (SD – 2) * 4 = Loss
Measuring uniformity using SD • An SD of 2 in. is the best we can hope for • Expected yield loss is 4 bu/inch
When to calibrate? • If the SD is greater than 3, planter needs calibration • Yield increases from calibrations of planter meters was profitable 83 percent of the time • Must still operate at a reasonable speed
QUESTIONS? THANK YOU