COVER CROP BENEFITS ON CLAYPAN SOILS

Newell Kitchen

USDA-ARS Cropping Systems and Water Quality Research Unit

Columbia, MO

Translating Missouri USDA-ARS Research and Technology into Practice A training session provided by USDA-ARS-CSWQRU, 10-11 October

2012, Columbia, MO

Why do we do cover crops?

We Need Cover!

Cover: blanket, canopy, cloak, hood, layer, shield, overlay, veil,cap

Poorly-Drained Upland Soils are not Exempt

Lost topsoil from erosionLost organic matterLost soil structureLower fertility

Lost topsoil from erosionLost organic matterLost soil structureLower fertility

What essential is “cover” when you’ve lost 60-90% of the function of that original soil?

How have we incorporated cover crops on the Precision Agriculture System (PAS)?

2005 , 2007, 2009 Wheat Cover

2006, 2011 Cereal Rye

2007 Sudex (following wheat)

2008 Rye Grass

2009-2012 Grass/Legume/Brassica Mix

What benefits do we see with cover crops?

What benefits do we see with cover crops?

Mulch tillage, Corn-soybean rotation (MTCS)

No-till, Corn-soybean-wheat rotation (NTCSW cover)

Quickly shows reduced erosion

Improved Water Quality

What are the hidden below ground impacts of cover crops?

CRP (cool)

CRP (warm)

hay (cool & warm)

Improved Water Infiltration

0

10

20

30

40

50

60

70

Footslope Backslope Summit

Landscape

Ag

gre

ga

te s

tab

ility

, %

Min. Till CS (1)No Till CS (2)ICM No Till CSW (5)CRP (6)

Improved Soil Aggregate Stability

Avg. N O 3-N (kg ha -1 90cm -1) C over: 16.7 N o-C over: 118.8

0 20 40 60

NO 3-N (kg ha -1)

80

60

40

20

0

Pro

file

De

pth

(cm

)

Recovered Nitrogen after Drought

Changes in other Soil Quality Indicators

Property and units 2003 2007

pH 6.18 6.34

P, mg/kg 7.6 15.1

K, mg/kg 60.9 133.6

SOC, g/kg 11.5 12.4

POM-C, g/kg 1.49 2.51

MnOxC, g/kg 0.344 0.342

Total N, g/kg 1.07 1.18

POM-N, g/kg 0.117 0.166 Highlighted items are significantly different between samplings

Typical Positive Impacts from Cover Crops on Soil Physical Properties

• Increased soil organic matter• Enhanced infiltration• Enhanced aeration• Improved soil structure/aggregation• Decreased soil strength• Preventive of soil compaction• Reduced evaporation potential