Arthropod Diversity Arthropod Diversity and Cover Cropsand Cover Crops

By Jeffrey TaylorBy Jeffrey Taylor

August 11,2003August 11,2003

Pennsylvania State UniversityPennsylvania State University

Arrival of the StudyArrival of the Study

Land owner Steve Land owner Steve Groff is interested Groff is interested to see what the to see what the benefits of long-benefits of long-term cover term cover cropping arecropping are

HypothesisHypothesis Fields with the least disturbance and a Fields with the least disturbance and a

cover crop would have the greatest cover crop would have the greatest diversity and abundance of arthropodsdiversity and abundance of arthropods

Study AreaStudy Area

Most DisturbedMost Disturbed

-Long term no-till ~20 years-Long term no-till ~20 years

Least DisturbedLeast Disturbed

-Pasture and then 7 years in no-till-Pasture and then 7 years in no-till

www.countryside-management.org.uk/ heathland/grazing.htm www.oznet.ksu.edu/notill/ images/nf_corninmay2.jpg

Study AreaStudy Area

Sixteen plotsSixteen plots– 4 Long term no-till with a cover crop4 Long term no-till with a cover crop– 4 Long term no-till without a cover crop4 Long term no-till without a cover crop– 4 Short term no-till with a cover crop4 Short term no-till with a cover crop– 4 Short term no-till without a cover crop4 Short term no-till without a cover crop

Study AreaStudy Area

Study AreaStudy Area

2003: Field corn in a rye cover crop2003: Field corn in a rye cover crop 2002: Soybeans in a rye cover crop2002: Soybeans in a rye cover crop

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Methods of CollectionMethods of Collection

Pitfall TrapPitfall TrapCatches surface insects

Tullgren Traps

Catches soil insects

Methods of CalculationMethods of Calculation

AbundanceAbundance

-Addition of all insects caught-Addition of all insects caught DiversityDiversity

-Shannon index-Shannon index

-D=--D=-ΣΣppiilogplogpii

FactorsFactors

Diversity Diversity AbundanceAbundance HerbivoreHerbivore Predators Predators DetritivoresDetritivores

Collection DatesCollection Dates

Tullgren: July 15, Tullgren: July 15, 20032003

July 28, July 28, 20032003

Pitfall: July 15-17, Pitfall: July 15-17, 20032003

July 28-30, July 28-30, 20032003

What was FoundWhat was Found

In The PitfallsIn The Pitfalls

Orthoptera-cricketsOrthoptera-crickets Hymenoptera-antsHymenoptera-ants Isopoda-pill bugsIsopoda-pill bugs Araneae-spidersAraneae-spiders

Ant

Pill bug

Cricket

In the Tullgren TrapsIn the Tullgren Traps

MitesMites Collembola-Collembola-

springtailsspringtails Diptera-fliesDiptera-flies

springtail

Mesostigmatid mite

Mesostigmatid mite

ResultsResults

treatments do not differ significantly at p> 0.05

aa

ResultsResults

a, b indicate treatments that differ significantly at p< 0.05

a a

b

b

aaa

a

b

b

ResultsResults

Total Total AbundanceAbundance

OrganicOrganic

MatterMatterLong term no-till Long term no-till with no cover with no cover cropcrop

32.7732.77 2.8%2.8%

Long term no-till Long term no-till with cover cropwith cover crop

29.6329.63 3.0%3.0%

Short term no-till Short term no-till no cover cropno cover crop

19.1419.14 3.6%3.6%

Short term no-till Short term no-till with cover cropwith cover crop

13.5213.52 4.7%4.7%

ConclusionConclusion

Only the tullgren traps were studied in-depthOnly the tullgren traps were studied in-depth Population may be migrating between plotsPopulation may be migrating between plots Abundance of Arthropods was greater in the Abundance of Arthropods was greater in the

long term no-till fieldslong term no-till fields

soils.usda.gov/sqi/SoilBiology/ ATLAS103_LR.jpg

ConclusionConclusion

Michael Hutson studied that diversity may Michael Hutson studied that diversity may decrease as fertility of soil increases decrease as fertility of soil increases

-competitors completely dominate fertile -competitors completely dominate fertile environmentsenvironments

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