Post on 01-Jun-2020
Tillage and Cover Crops2012 LOUISIANA AGRICULTURAL TECHNOLOGY &
MANAGEMENT CONFERENCEParagon Casino Resort
Marksville, LAFebruary 15-17, 2012February 15-17, 2012
Kip Balkcom
Research Agronomist
USDA-ARS
National Soil Dynamics Laboratory
Auburn, AL
Total Organic C and N
Total Organic C and N
BulkBulk
SizeSizeDistributionDistribution
NH and NO , NH and NO , P, K, Ca, Al, P, K, Ca, Al,
CECCEC
NH and NO , NH and NO , P, K, Ca, Al, P, K, Ca, Al,
CECCEC
33334444
Microbial Biomass Microbial Biomass C and NC and N
Aggregate Aggregate StabilityStability
Soil C is the basis of Soil Quality/Productivity
from Doran et al., 1993from Doran et al., 1993
InfiltrationInfiltration
SoilSoilStrengthStrength
BulkBulkDensityDensity
WaterWater
contentcontent
retentionretention
capacitycapacity
C and NC and N
SoilSoilRespirationRespiration
NN
Biomass CBiomass Cto TOC ratioto TOC ratio
RespirationRespirationto Biomass ratioto Biomass ratio
mineralizedmineralized
How to increase soil C and improve soil quality?
Conservation Tillage with Cover Crops
Conservation System
Conventional Tillage Promotes Soil Erosion
Manage compaction . . .Manage compaction . . .
Non-inversion Tillage
Tillage and rye cover crop effects on SOM after 5 yTillage and rye cover crop effects on SOM after 5 y
00
22
44
SOM (%)SOM (%)00 11 22 33 44 55
88
66
44
1010Decatur silt loam
No-Till w/o coverNo-Till w/o cover
Conventional w/o coverConventional w/o cover
No-Till w/ coverNo-Till w/ cover
Fall Paratill w/ coverFall Paratill w/ cover
Effect of cropping/tillage system on soil C from an eroded Ultisol in Georgia.
0-15 mm0-15 mm15-30 mm15-30 mm30-80 mm 30-80 mm
3030
2525
2020
conversion to conventional till
soybean
conversion to conventional till
soybean
Grain sorghum no-till intocrimson clover
Grain sorghum no-till intocrimson clover
Bruce et al., 1995Bruce et al., 1995
30-80 mm 30-80 mm
55
1010
2020
1515
19841984 19861986 19881988 19901990Year Year
Depression (11%)Conventional: 2937 lb/AConservation: 3255 lb/A
Depression (11%)Conventional: 2937 lb/AConservation: 3255 lb/A
ConventionalConventionalConservationConservation
ConventionalConventional
ConservationConservation
ConventionalConventional
{{{{
{{
Field Scale ResearchField Scale Research
Conventional Conventional
Conservation Conservation
Eroded Slope (16%)Conventional: 2440 lb/AConservation: 2830 lb/A
Eroded Slope (16%)Conventional: 2440 lb/AConservation: 2830 lb/A
Plateau (14%)Conventional: 2651 lb/AConservation: 3032 lb/A
Plateau (14%)Conventional: 2651 lb/AConservation: 3032 lb/A
Conservation Conservation
Conservation Conservation Conventional Conventional
Conventional Conventional
}}}}
What is a Cover Crop?
• A crop whose main purpose is to benefit the soil and/or a subsequent crop in subsequent crop in one or more ways, but is not intended to be harvested for feed or sale.
Courtesy: Harry Schomberg, USDA-ARS
High Residue Cover Crop
Why use Cover Crops?• Erosion control
• Soil and water quality improvement
• Increased water infiltration infiltration
• Minimize nutrient loss
Soil organic carbon
Soil organic carbon
Tennessee Valley-Clay SoilsTennessee Valley-Clay SoilsNo-Till w/o Cover CropNo-Till w/o Cover Crop
Tennessee Valley-Clay SoilsTennessee Valley-Clay SoilsNo-Till with Cover CropNo-Till with Cover Crop
3000
3500
4000
4500
5000
PD 2
PD 1
Planting Date - Clover Biomass
0
500
1000
1500
2000
2500
3000
EVS2004 EVS2005 TVS2004 TVS2005 JAY2005
PD 3
PD 4
PD 5
Courtesy: Andrew Price
Winter Cover Crop Biomass and Weed Suppression
800
1200
Wee
d bi
omas
s (k
g/ha
)
0 2000 4000 6000 8000 10000
0
400
800
Rye biomass (kg/ha)
Wee
d bi
omas
s (k
g/ha
)
Cover crop planting date affects rye biomass and pigweed density
6000
8000
10000
Rye
Biom
ass
(kg/
ha)
600000
80000010000001200000
Pigw
eed
Den
sity
(p
lant
s/ha
)
0
2000
4000
PD1 PD2 PD3 WF CT
Treatment
Rye
Biom
ass
(kg/
ha)
0
200000400000600000
Pigw
eed
Den
sity
(p
lant
s/ha
)
Cover Crop Fertilization
90 lb N ac-1 0 lb N ac-1
N Fertilizer Effects on Rye Cover Crop Biomass Production
Rye
biom
ass,
kg
ha-1
8000
10000
12000
14000200320042005
WGS Headland, ALNitrogen rate, kg ha-1
0 34 67 101
Rye
biom
ass,
kg
ha
0
2000
4000
6000
8000
Rainfall Simulation Study . . .
*No Deep Tillage*No Deep Tillage100100
8080
6060
Tillage and residue effects on infiltration of a Coastal Plain Soil (2-inch rain event)
Tillage and residue effects on infiltration of a Coastal Plain Soil (2-inch rain event)
11 days11 days
00
60
4040
2020
No Till w/ residue
No Till w/ residue
No Till w/o residue
No Till w/o residue
ConventionalTillage
ConventionalTillage
3 days3 days
Soil Water Conservation
Plot 141Plot 141 Plot 142Plot 142
Timing Termination
MAY 1
Bio
mas
s, lb
ac-1
8000
10000
12000200420052006200720082009
Biomass Production Time of Termination
Bio
mas
s, lb
ac
0
2000
4000
6000
RyebeforeCorn
WheatbeforeCotton
RyebeforeCotton
WheatbeforeCorn
Methods of Termination
Physical methods• Incorporation
• Mowing
• Mechanical Rolling
Roller Variations
Roller Variations
Roller Variations
Roller Variations
Rollers/crimpers developed at the NSDLTwo-Stage
roller/crimperU.S. Patent pending
(Kornecki)
Smooth roller with crimping bar
U.S. Patent pending(Kornecki, et al.)
Roller for elevated beds:U.S. Patent allowed
(Kornecki)
One row – two furrows
Two rows – three furrows
Less vibration transferred to tractor, adjustable crimping force, a unique crimping bar design to accommodate for uneven soil surface
Compact design, with adjustable crimping force. Drum with crimping bars isolated to minimize vibration. Intended for small vegetable farm operation: Designed both for field
and vegetable crops
Ripper Modification
Planter Attachments
Summary• Plant covers in a timely fashion.
• Consider additional N fertilizer for small grain cover crops, especially if residual N is low.
• Terminate covers ~ 3 weeks ahead of • Terminate covers ~ 3 weeks ahead of anticipated planting date to allow soil moisture recharge and reduce problems with equipment operation.
• Take advantage of equipment modifications to facilitate tillage and/or planter operations in heavy residue.
Tillage and Cover Crop Resources• Managing Cover Crops Profitably, 3rd ed. Sustainable
Agriculture Network. www.sare.org/publications/covercrops/covercrops.pdf
• UC SAREP Cover Crop Resource Page www.sarep.ucdavis.edu/ccrop/
• National Sustainable Agriculture Information Service (ATTRA) www.attra.org
• Schomberg, H.H., and K.S. Balkcom. Cover crops [Online]. Available at: www.soilquality.org/practices/cover crops.html
www.ars.usda.gov/msa/auburn/nsdl