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This presentation demonstrates how cover crops can sequester nutrients, provide biological nitrogen
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NITROGEN PRODUCTION AND NUTRIENT SEQUESTRATION
Nitrogen Benefit
Biological Nitrogen Fixation
Timing of Hairy Vetch Harvest and Corn Yield
Adapted from Gallagher, Penn State
2007 Hairy Vetch Corn Yield-0 NTime lbs/acre %N N lbs/acreEarly (May 4) 1,400 3.82 55 113Middle (May 15) 4,300 4.43 190 132Late (May 31) 6,600 4.15 274 140
2008Early (May 1) 3,204 2.49 80 92Middle (May 14) 4,005 2.92 117 121Late (May 29) 4,361 4.55 197 79
Growth Stage Will Make a Difference
1500-2000 lbs/acre 4-5,000 lbs/acre
N Release over Time From Cover Crops in North Carolina
2 4 8 12 160
10
20
30
40
50
60
70
80
90
100
Rye
Crimson Clover
Hairy Vetch
From Wagger, 1989. Agronomy Journal
lbs/
acr
e
Weeks
% N Remaining Over Time
From Wagger, 1989, Agronomy Journal
Harvest Time on N and C:N Ratio
Cover Crop Harvest Time Dry Wt N ConcentrationTotal N C:Nlbs/acre % lbs/acre
Rye Early 6355 1.49 94 27:1Rye Late 8144 1.25 101 32:1Crimson Clover Early 3827 2.76 106 14:1Crimson Clover Late 5260 2.48 131 16:1Hairy Vetch Early 3720 3.69 131 11:1Hairy Vetch Late 6337 3.22 204 12:1
From Wagger, 1989. Agronomy Journal
Corn Yield From Kentucky
0 50 1000
20
40
60
80
100
120
140
160
Hairy Vetch Crimson Clover
Rye Control
187 lb N/acre
50 lb N/acre
36 lb N/acre
From Ebelhar et al, 1986
Missouri Data-Bradford 1990’s
Corn Grain Sorghum
Species Seed Rate Dry Matter N Equivalent N Equivalent lbs/acre lb/acre lb/acre
lb/acre Hairy Vetch 30 1744 37.3 54.8 20 1451 40.2 46.5 Austrian Winter Pea 60 712 26.4 35.1 40 757 33.6 6.5
From Reinbott, et al, 2004 Agronomy Journal
2013 Corn Yield After Cover Crops
Corn Yield 2013 Cover Crops Overseeded into Soybean September 2012 Corn Treatment Yield Bu/acre Control 175 Hairy Vetch 199 Crimson Clover 165 Radish 174 Cereal Rye 175 Hairy Vetch+Rye 187 Crimson Clv. +Rye 181 Radish + Rye 173 Rye+Radish+HV+CC 174
Reinbott, 2013
Not As Much Yield Advantage As It Looked
Results From Using Cover Crops
7 more Bushels/acre
Seed Cost-$45/acre
7 bushel/acre @ $13/bushel=$91/acre
Or about $46/acre profit
2013 Soybean Yield After Cover Crops
Soybean Yield 2013 Cover Crops Overseeded into Corn Sept. 2012 Treatment Yield Bu/acre Control 29 Hairy Vetch 24 Crimson Clover 28 Radish 27 Cereal Rye 36 Hairy Vetch+Rye 28 Crimson Clv. +Rye 33 Radish + Rye 29 Rye+Radish+HV+CC 27
Reinbott, 2013
WHAT OTHER BENEFITS DO RYE, RYEGRASS, AND TILLAGE RADISH HAVE?
Nutrient Scavenge, Loosen Soil, Weed Control
Tillage Radish Root dug out-32”Courtesy of Steve Groff-Pennsylvania
TillageRadish®
field
Openfield
Soil compactiondecreased by >40%
Ohio State UniversityCourtesy of Steve Groff
Loosen Soil-Increase root growth and water infiltration?
Less Compaction Equals More Root Density Deeper Following Radish and Rye
Gruver, et al, 2012
Soybean Roots Follow Cover Crop Root Channels
Williams and Weil, 2004
NUTRIENT SEQUESTRATION
Percent Total Available P and K at Different Depths in the Soil Profile-Silt
Loam-Silty Clay Loam
P K0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
36 to 4829 to 3624 to 2918 to 2412 to 189 to 123 to 90 to 3
Clark and Reinbott, 2012
0
6
12
18
24
30
36
42
48
0 20 40 60 80 100 120 140 160
Soil Nutrients, lb per acre
So
il d
ep
th, in
ch
es
P & K build up on Sands
N P KCourtesy of David Dunn, 2013
N P K
Soil Potassium Levels After Three Years of Cover Crops
0 to 3 3 to 6 6 to 120
20
40
60
80
100
120
140
noneRyeCrimson CloverHairy Vetch
lb K
/acr
e
Hargrove et al, 1986
Increase in Soil Test P Around Tillage Radish Roots by 2X
1.25 inch
2 inches
White and Weil, 2011
Nitrogen Capture By Tillage Radish
-10
10
30
50
70
90
110
130
150
Shoot
RootCornCorn
Soybean
Soybean
Lbs/
acr
e
Dean and Weil, J Eniv. Quality 2009
Radish and Rye Capture Nitrate-N in the Soil Profile
NOT ALWAYS POSITIVE
Cotton Lint and Seed Yield Decreases Following a Rye or Wheat Cover Crop
Lint Seed Wheat Rye ControlWheat Rye Control
Cotton 886 854 1129 1368 1333 1831
lb/acre
Li, et al, Agronomy Journal 2013
WHAT ABOUT WATER?Infiltration, Run-off, Conservation
From Steve Groff
Cover Crop No Cover Crop
Cover Crops Reduce Water Runoff or Increase Water
Infiltration
Water From Tilled (left), No-Till (middle) and No-Till With Cover Crop (right)
QUESTIONS?