7/30/2019 Shantel King- Proposal Abstract1

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Microbial Diversity and Enzyme Activity in

Organic Farming vs. Conventional Farming

Shantel L. King

Major Advisor: Dr. Ramble O. Ankumah

Over the last twenty years organic farming acreages have increased as an alternative solution to

the traditional or modern agriculture which practice is heavily dependent on inorganic fertilizersand other agricultural chemicals (pesticides, herbicides, fungicides and insecticides). These

practices have been associated with loss of soil fertility, soil erosion, and ground water pollution

which in turn can affect the ability of soils to process nutrients and waste, and can also affect

ecosystem processes. Understanding the effects of organic farming on soil functions as compared

to conventional agriculture is important in protecting soils from degradation and improving

ecosystem processes in soils. These land uses have also been reported to impact soil microbial

and biochemical properties. Soil enzyme activity and microbial community assessment have been

suggested as possible measures of the soil ecosystems function. Among soil enzyme activity

measurements reported to correlate with soil biological activity are dehydrogenase, alkaline

phosphatase, arylsulfatase, and phosphodiesterase. For example alkaline phosphatase activity has

been correlated with microbial respiration, biomass, and soil organic matter, and

phosphodiesterase activity has been associated with breakdown of nucleic acid. Recent reports

have also indicated that measurement of microbial community composition and shifts in response

to disturbances in the soil may offer insight and opportunities in quantifying the effect of land use

and environmental influences on a soils ability to function properly. This in turn may help in the

search for general indicators, which could be used to assess soil quality. This study seeks to

examine the impact of organic farming and conventional farming systems on soil quality using

soil enzyme quality and microbial diversity as measures of soil quality. The specific objectivesare: to evaluate the effects of organic and conventional farming on microbial diversity (ii) soil

enzyme activity and iii) compare these with soil chemical and physical parameters (organic

matter, pH and bulk density). Soil samples will be collected from two long term organic and non-

organic farming plots located in Roanoke, PA. Microbial diversity will be determined by whole

DNA extraction followed by DGGE. Soil enzyme activity will be measured using the

phosphomoesterases and phosphodiesterase as a measure of enzyme activity. In addition to these

measurements, soil organic carbon, pH and bulk density will be measured. Results from

community measurements will be compared with organic matter content, and soil enzyme

activities. A relationship of how these parameters are influenced by the two farming systems will

then be evaluated. It is hypothesized that the organic farming plots will have higher organic

matter, microbial diversity and soil enzyme activity compared to the conventional tillage plots.

. References:

1. Esperschutz J., Gattinger, A., Mader, P., Schloter, M. and FleiBach, A. (2007)Response of soil

microbial biomass and community structures to conventional and organic farming systems under identical

crop rotations. FEMS Microbiology Ecology. 61 26-37.

2. Anna K. Bandick and Richard P. Dick. 1999. Field management effects on soil enzyme activities. SoilBiology and Biochemistry.31:1471-1479.

3. Bo, L., Cong, T., Shuijin, H., Gumpertz, M., Ristaino, J.B. 2007. Effect of organic, sustainable, and

conventional management strategies in grower fields on soil physical, chemical, and biologicalfactors and the incidence of Southern blight. Applied Soil Ecology. 37:202-214.

http://www.sciencedirect.com/science/journal/00380717http://www.sciencedirect.com/science/journal/00380717http://www.sciencedirect.com/science/journal/00380717http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235163%231999%23999689988%23114774%23FLA%23&_cdi=5163&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0fb8bac478d1fdf0e11a2e2bb7319dcchttp://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235163%231999%23999689988%23114774%23FLA%23&_cdi=5163&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0fb8bac478d1fdf0e11a2e2bb7319dcchttp://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235163%231999%23999689988%23114774%23FLA%23&_cdi=5163&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0fb8bac478d1fdf0e11a2e2bb7319dcchttp://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235163%231999%23999689988%23114774%23FLA%23&_cdi=5163&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0fb8bac478d1fdf0e11a2e2bb7319dcchttp://www.sciencedirect.com/science/journal/00380717http://www.sciencedirect.com/science/journal/00380717http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235163%231999%23999689988%23114774%23FLA%23&_cdi=5163&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0fb8bac478d1fdf0e11a2e2bb7319dcc