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Symphylans and Salinity:. Management of the Greenhouse. Penn State AgroEcology Internship. Maureen Copeland Summer, 2003. Problems at Sonnewald Farm. Plants suffering in Old Greenhouse during 2002 Thought to be caused by symphylans. Symphylans: Overview.
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Symphylans and Salinity: Management of the Greenhouse Penn State AgroEcology Internship Maureen Copeland Summer, 2003
Problems at Sonnewald Farm • Plants suffering in Old Greenhouse during 2002 • Thought to be caused by symphylans
Symphylans: Overview • Food: Organic matter (e.g. plant roots, sprouting seeds) • Migrate vertically through the soil; found in depths up to one meter deep
Hypothesis • Lower organic matter will reduce the symphylan population- less food • Lower salinity will improve plant growth & provide a better habitat for predators, reducing symph population
The Treatments • Control (greenhouse soil) • Intermediate soil (1:1 greenhouse to outside soil) • Most diluted soil (2:1 ratio) • Low salinity
Plot Setup Low Saline 2:1 1:1 2:1 Control 1:1 Low Saline Low Saline 1:1 Control 2:1 Control Replicate 1 Replicate 2 Replicate 3
What I did • Set aside one bed in the Old Greenhouse for experiment • Planted with Ermosa lettuce in each plot after taking initial soil samples • Took 2 types of samples on 3 days • June 16, July 13, and July 30
Methods • Symph bait • use beet slices under a container for 24 hours to collect soil arthropods From: http://www.seedswestgardenseeds.com/beetsindex.html
Methods • Berlese Funnel: take small soil samples and place in a funnel with light on top • Light drives organisms downward into vial of alcohol
Results • One symph found in all the samples taken • Where did they go?
2:1= 2parts outside soil : 1 part greenhouse soil 1:1= 1part outside soil : 1 part greenhouse soil Most diluted soil= more organisms?
More Results Difference between control and most diluted soil is significantly different
Further considerations • Temperature: • Earlier samples- higher abundance • Leaching out salts: leach out nutrients? • Low OM is still high compared to “typical farms”
Interpretations • Possible that symphs migrated downward during warmer summer season • Supported by evidence that deep soil samples had more symphs than any other samples • Does not explain some things…
Are Symphylans really the problem? • This season- pepper plants in new greenhouse are struggling • no symphs found • Measured EC
Salinity & Bugs • Salt level appears to be affecting diversity of soil dwelling organisms From: http://www.laters.com/insects/springta.htm
How does high salinity occur? • Manure inputs: • Compost with manure had higher level of salts than plant-only compost • Manure compost= 1.47mmhos/cm • Plant-based compost= 0.29mmhos/cm • Lack of rain: salts are not leached
What this means • Possible that symphs were causing some of last years damage. However… • More likely that combination of high salinity & symphylans stressed greenhouse crops