ANOVA, p < 0.0370

• Variation likely due to grower management practices as there is not trend by crop type

• Several sites are below 500 ppm active carbon which may indicate a constraint on the production system

Grower Driven Rotations and On-Farm Test

Fall data reveals significant variation for permanganate oxidizable carbon (POXC)

Nematode Collection Methods

Top 0-6 inches

Bottom 6-12 inches

Mix

Mix

Extract nematodes from soil

Count by size• Small- bacterial feeders• Large- pathogenic

Baermann funnel

Bottom

Significant variation for total nematode counts

• Significant variation in nematode numbers by crop type.• Barley increases nematode numbers—in both depths

Spring Fall

Top

Spring Fall

• Small and large nematodes increase on barley• Large nematodes increase across all the crops but more so in Barley

Small and large nematodes are increased in barely

Top Bottom Top Bottom

Top 0-6 inches

Bottom 6-12 inches

Mix

Mix

Extract Microbe DNA

Barcoded ampliconsequencing

• ITS2 - Fungi•V4 - Bacteria•18s - Nematodes

Characterizing changes in microbial communities

Sequencing depth and core microbial communities – Spring 2017

• Average depth 10,000x• 517 OTUs• 217 - core community

distributed across most fields

Bacterial communities

• Average depth 15,000x• 278 OTUs• 149 - core community

distributed across most fields

Fungal Communities

OTU – operational taxonomic unit

Significant difference between top and bottom soils for both bacterial and fungal communities

Non-metric multidimensional scaling (NMDS)

Circles represent the 95% confidence

intervals within a group. Objects that are

more similar to one another are ordinated

closer together.

Fungal Communities

Bacterial Communities

Stress = 0.012

Stress = 0.005

Similarity among

bacterial communities

in top soils

Bacterial Communities – Top Soils

Stress = 0.015

Clustering by cover crop

among fungal communities

in top soils

Fungal Communities – Top Soils

Stress = 0.014

Some clustering by

cover crop among

bacterial communities in

bottom soils

Bacterial Communities – Bottom Soils

Stress = 0.009

Clustering among fungalcommunities

in bottom soils

Fungal Communities – Bottom Soils

Stress = 0.018

0

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nsi

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B B B B T T T T

Fusarium

Alternaria

Colletotrichum

Leptosphaeria

Verticillium

Alternaria (Early Blight)

Fusarium (Dry Rot)

Collectotrichum(Black Dot)

Verticillium (Wilt)

Leptosphaeria(Blackleg)

Top Soils

Pathogenic Fungi

Bottom Soils Top Soils

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ads

Beneficial Fungi

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B B B B T T T T

Mortierella

Tetracladium

Arthrobotrys

Penicillium

Mortierella

Tetracladium

Arthrobotrys Top SoilsBottom Soils Top Soils

Nu

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of

read

s

Significant differences in communities

Cover crop comparison - FungiDf Variance F Pr(>F)

crop 3 0.0563 8.7217 0.001 depth 1 0.0328 15.1266 0.001 crop:depth 3 0.0173 2.6650 0.001Residual 181 0.39262

Cover crop/grower - FungiDf Variance F Pr(>F)

plot 9 0.1421 9.2373 0.001depth 1 0.0328 19.1964 0.001plot:depth 9 0.0356 2.3175 0.001Residual 169 0.288928

Cover crop/grower - BacteriaDf Variance F Pr(>F)

field 9 0.06893 6.8853 0.001depth 1 0.04506 40.5329 0.001field:depth 9 0.02357 2.3561 0.001Residual 170 0.18902

Cover crop comparison - BacteriaDf Variance F Pr(>F)

crop 3 0.02359 5.8050 0.001depth 1 0.04506 33.2600 0.001depth:field 3 0.01128 2.7768 0.001Residual 182 0.24662

Permutation based multivariate analysis of Anova (MANOVA)

Differences in microbial communities driven by both grower field and cover crop

Next steps:

• Make comparisons between years (within a field)– Waiting for data for Fall (2017), will collect (Fall 2018)

• Analyze nematode genetic soil data, along with nematode count data– Waiting for data Spring and Fall (2017), will collect

• Examine pathogen pressure over time/change in cover crop

Summary and Take Homes

1. Interesting trends on yield and rotational crops

2. Rich fertility data with lots of leads to begin to follow

up

3. Nematodes increased on barley and likely pathogenic

to barley as well

4. Cover crops change the microbial community

composition and will change through time

Grower Input and Questions

Special thanks to:Jim Ehrlich

Potato Research Board

Kristen OttoJorge Ibarra