alternative winter cover crops and systems for virginia
DESCRIPTION
Alternative Winter Cover Crops and Systems for Virginia. Cover crops offer the best opportunity to “intensify” our current row crop rotations Increase soil organic matter Retain and cycle nutrients Retain water Manage pests?. Species Demonstrations. Early Cover Hairy Vetch Common Vetch - PowerPoint PPT PresentationTRANSCRIPT
Alternative Winter Cover Crops and Systems for Virginia
• Cover crops offer the best opportunity to “intensify” our current row crop rotations
• Increase soil organic matter • Retain and cycle nutrients• Retain water• Manage pests?
Species Demonstrations• Early Cover Hairy Vetch • Common Vetch • Wooly pod vetch (Lana)• Crimson Clover • Austrian Winter Peas
• Sweet Lupins • Tillage Radish • Phacelia
• Rye • Barley • Ryegrass • Spring oats
• Barley+Crimson+tillage radish • Rye+Vetch+Pea+tillage radish • Rye+ryegrass+tillage radish • Spring oats+canola • Spring oat+tillage radish • Spring oat + barley • Barley+Crimson+Woolly Pod
Vetch+Peas +tillage radish+canola
• Ryegrass+Crimson+Woolly Pod Vetch+Peas +tillage radish+canola
WINTER SPRINGDM BIOMASS
N UPTAKE
DM BIOMASS
N UPTAKE
---------LB/AC---------
---------LB/AC---------
Rye+Ryegrass+Tillage radish 1660 57 3277 76Barley 1543 55 2705 57Ryegrass+Crimson+Woolly Pod Vetch+Peas +Tillage radish+Canola 1426 49 2556 68Rye+Vetch+Pea+Tillage radish 1343 41 2705 62Barley+Crimson+Tillage radish 1327 44 2513 58Tillage Radish 1285 43 211 3Barley+Crimson+Woolly Pod Vetch+Peas+Tillage radish+Canola 1264 39 1848 40Rye 1251 36 2376 59Spring oats+Tillage radish 1239 40 1289 22Phacelia 1092 38 506 12Spring oats+Canola 1054 33 2173 46Spring oats 1052 33 1112 17Ryegrass 954 30 1556 32Wooly pod vetch (Lana) 728 24 1610 50Crimson Clover 685 16 1385 38Indian Head Lentils 655 21 107 4Common Vetch 576 17 525 17Austrian Winter Peas 566 17 565 25Spring Oat + Barley 500 11 2087 30Sweet Lupins 491 14 730 14Persian Clover 442 12 202 4Early Cover Hairy Vetch 318 11 1374 40Yellow Sweet Blossom Clover 244 5 525 11Arrowhead Clover 180 4 265 6Subterranean Clover 168 2 191 5
Rye Biomass
2100 lb/ac1100 lb/ac 3490 lb/ac
390 lb/ac 796 lb/ac199 lb/ac
Summary
• Fall growth– Rye, barley, and mixtures with them– Radish, phacelia, and spring oats
• Spring growth– Rye, barley, and mixtures with them– Vetch and clover (depending on termination)
Summary
• Canola deserves a look• Mixtures were surprisingly good
Mar 22, 2006Rye+Vetch Early Rye+Vetch Late
Oats Late
Growth Response to Temperature
200 GDD 400 GDD 600 GDD0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Tillage RadishCanolaPhaceliaRyeBarleyAustralian Winter PeaWoolypod VetchEarly Cover Hairy VetchSpring OatsRyegrassCommon VetchCrimson CloverSweet Lupin
DM Y
ield
, kg/
ha
38
550
2250
Species X Date Interseeded into Soybean, 2012-13. Average of 4 locations
Rye Barley Rye+hairy vetch Rye+tillage radish
0
100
200
300
400
500
600
700
800
900
1000
10-Sep24-Sep8-Oct22-Oct5-Nov
DM B
iom
ass,
kg h
a-1
Aerial/Broadcast Seeding “Success”
Aerial/Broadcast Seeding “Success”All types Rye only Legumes
Dry Matter, lb/ac in December
------% of samples------
<200 lb/ac 40% 9% 75%<800 lb/ac 46% 29% 92%>800 lb/ac 54% 61% 8%
Rye Only
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 330
500
1000
1500
2000
2500
3000
DM B
iom
ass,
kg h
a-1
Shen Valley – early September planting
After Oct 25
Little/no rain after seeding
Planted before Oct 8
Natural Leaf Drop Vs. Chemical Defoliation, Suffolk
(Dual + Prowl PRE fb Roundup + FirstRate POST to Soybean)
Rye+R
adish
Rye+V
etch
Sprin
g Oat
Sprin
g Oat+
Radish
Barley Rye
0
200
400
600
800
1000
1200
1400
1600
1800
NoneParaquat
DM B
iom
ass,
kg h
a-1
LSD = NS
Natural Leaf Drop Vs. Chemical Defoliation, Blacksburg
None Paraquat0
500
1000
1500
2000
2500
3000
Rye
DM B
iom
ass,
kg h
a-1
LSD = NS
Wheat Stubble Management Effects on Winter Cover Establishment
Blacksburg Suffolk0
500
1000
1500
2000
2500
Standing Stubble
Baled Stubble
Cultipacker or Vertical tillage
Tilled
Biom
ass Y
ield
, kg
ha-1
LSD = NS
Cover Crop Species for Broadcast Seeding into Soybean Canopy
(Dual + Prowl PRE fb Roundup + FirstRate POST to Soybean in Suffolk)
Blacksburg Suffolk0
500
1000
1500
2000
2500
3000
Rye+Radish
Rye+Vetch
Spring Oat
Spring Oat+Radish
Barley
Rye
DM B
iom
ass,
kg h
a-1
LSD = NS
Leaching and EFI
• EFI = Precip * soil AWHC
0 1 2 3 4 5 6 7 80
102030405060708090
100
Exchange Frequence Index
Est.
N lo
ss o
verw
inte
r, 0-
60 c
m
Exchange Frequency Index
<1.5 0.5-1.5 1.5-2.5 >2.5
Rel. Risk Low Moderate High Very High
% of years in leaching risk category
Loamy Sand 0.7 41.1 37.6 20.6
Sandy Loam 7.1 59.6 31.9 1.4
Silt Loam 12.1 69.5 18.4 0