Friday, August 8, 2008

PS 87-153: Evaluation of the restoration at East Jester’s Creek: Soil nutrients

Japhia M. Jacobo and Jere Boudell. Clayton State University

Background/Question/Methods
Clayton County, Georgia is acknowledged as a rapidly urbanizing area which was subjected to poor agricultural techniques used during the cotton farming era. The plant communities inhabiting the riparian ecosystems in Clayton County are degraded.  In 200, the Clayton County Water Authority initiated a Stream Improvement Program which prioritized and designed improvements for the degraded stream systems.

To determine the potential success of the East Jester’s Creek restoration project, we conducted a comparison between East Jester’s Creek and Little Falling Creek located in Jasper and Jones County, GA. Little Falling Creek, our reference site, is the only functioning low order Piedmont stream that is not wholly eroded.  To better understand the soil characteristics of East Jester’s Creek, we evaluated the amounts of available Nitrogen, Phosphorous, and Potassium. We stratified East Jester’s Creek into 3 communities –field, bank, and active channel. We selected 6, 100m2 sites per community and randomly selected three plots per site for study. We compared soil characteristics amongst communities.

Results/Conclusions
Some nutrients varied amongst communities at East Jester’s Creek. Potassium levels were significantly higher in the field and bank than in the active channel sites. Phosphorous levels were significantly different between the field and the active channel sites, but no significant difference was found between the active channel and the bank sites or the bank and the field sites. No significant difference was found between the communities in nitrogen levels, but the total pounds per acre of nitrogen were lower in all three communities than the potassium and phosphorous levels.

Soil nutrient levels between the communities can be affected by the environmental conditions found in impacted stream systems. The significant difference in phosphorous and potassium levels between the field and the active channel sites suggests that the constant movement of water near the stream bank causes a change in the amount of mineral nutrients available; this difference has been found in other studies. Lower amounts of nitrogen in comparison to amounts of phosphorous and potassium may be caused by nitrogen leeching. Because nitrogen readily bonds to water, run-off at East Jester’s Creek may decrease overall nitrogen levels. This early assessment of East Jester’s Creek restoration project suggests that project success may be impacted by on-going problems with run-off and soil erosion.