How does flooding effect soil quality?• Reducing Pore Space: Loss of pore space can result in decreased infiltration rate, ultimately exacerbating runoff potential.• Lowering Soil Fertility: Anaerobic respiration can cause alterations in elemental availability. • Decreasing Mycorrhizal Colonization: Mycorrhizae facilitates increased plant uptake of nutrients.

What is Post Flood Syndrome?Post flood syndrome is the result of mycorrhizae loss in the soil. Mycorrhizae help increase the soil volume a plant has access to, aiding the plant in the uptake of nutrients. A study by Viebrock (1988) showed that plant roots with mycorrhizal colonization had access to phosphorus as much as 20-40X further than roots without mycorrhizal colonization. Mycorrhizae is a symbiotic fungus that inhabits cortical root cells. Without a host plant, mycorrhizae cannot live.

Case Study #1: Does Soil Fertility with Small-Scale Elevation Differences?

On four dates, soils were collected in and 18” field depression with an average difference of 2” in elevation. Over the course of one year, we found:

Higher correlations of elements and elevation during spring when soil has been minimally disturbed.

After the wettest two consecutive months recorded in Vermont, there was no correlation on such a small scale.

Individual treatments did not have a significant effect on soil fertility. However, when considering success of cover crop, outcomes differed between plots with established and unestablished cover crops.Preliminary results indicate that elevation in field position significantly affected fertility and corn growth, suggesting that cover crops need to be managed with respect to field position.

Case Study #2: Do Cover Crops Effect Soil Fertility?

Conclusion Acknowledgements

Six treatments were planted in October 2012. Soil samples from May 2013 were analyzed. Here’s what we found: Effect on Ca, Fe, Mn, P, and

S can be grouped as positive or negative by success of cover crop.

Treatments did not fall is such groupings for K, Mg, and Al.

Special thanks to: Alan HowardAlison BrodyJonathon GonzalezPurdue University Agronomy Department for right topmost picture of corn: http://www.agry.purdue.edu/ext/corn/news/articles.98/p&c9825.html

Flooding, Soil Quality, and Cover Crops: Two Case Studies

Lindsey Ruhl*, Josef Görres

*contact: lruhl@uvm.eduWebsite: www.floodedsoils.wordpress.org

Case Study #2: Does Elevation in Field Location Affect Soil Fertility?

Correlation of Elements with Elevation by Sampling Date

*based on .05>p-value

May 3, 2012 Oct. 18, 2012 April 9, 2013 June 21, 2013

Al YES (-) NO NO NO

Ca NO NO NO NO

Fe YES (-) NO NO NO

K YES (-) NO YES (+) NO

Mg NO NO NO NO

Mn YES (-) NO NO NO

P YES (-) NO YES (+) NO

Picture Date: May 7th ,2012 Picture Date: Oct. 9, ,2012

Picture Date: May 27th, ,2013

Al

M

g`

K CaM

nS

PFe

Mycorrhizae Colonization in Root Wall

4.2 4.3 4.4 4.5 4.6 4.7 4.80

102030405060

Number of Ears on Plants X Average Position

Number of Ears on PlantsLinear (Number of Ears on Plants)

4.2 4.3 4.4 4.5 4.6 4.7 4.80

20406080

100120140

Average Corn Height X Av-erage Position

Average HeightLinear (Average Height)

4.2 4.3 4.4 4.5 4.6 4.7 4.80

5

10

15

20

Average Leaf Biomass X Av-erage Position

Average Leaf BiomassLinear (Average Leaf Biomass)

Significant Correlations Between Al, Ca, Fe, S with Field Position

In May 2013, soil samples were taken from over wintered cover crop stands. We found: Fe, Mg, Mn, and moisture significantly

correlated with elevation in field position.

In late summer 2013, corn biomass and height were measured. Data shows: Elevation in field position has a statistically

significant impact on corn growth. Lower elevations in field positions have

lower plant growth than higher positions.4.2 4.3 4.4 4.5 4.6 4.7 4.8

0.00

5.00

10.00

15.00

20.00

25.00

Total Fresh Weight of Ears X Average Position

Fresh WeightLinear (Fresh Weight)

4.2 4.3 4.4 4.5 4.6 4.7 4.80

0.2

0.4

0.6

0.8

1

1.2Fe

4.2 4.3 4.4 4.5 4.6 4.7 4.810

12

14

16

18

20

22Mg

4.2 4.3 4.4 4.5 4.6 4.7 4.81

1.21.41.61.8

22.22.42.62.8

Mn

4.2 4.3 4.4 4.5 4.6 4.7 4.81517192123252729

Moisture

KM

gAl

Effect of Establishment Success: Ca, Mn, S

Effect of Establishment Success: P and Fe

Effect of Establishment Success: K, Mg, Al

Picture Date: March 29th, 2013