Monthly Measurement and Long Term Erosion on Bare Ground, Putnam County, Tennessee

Abstract

Cropland, much of which is bare ground, loses an estimated 10 million hectares of soil due to erosion each year.  Soil erosion occurs at rates 10 to 40 times greater than soil development by natural processes.   Soil loss is generally a slow-onset hazard and thus may go unnoticed when compared to more dramatic erosional processes such as landslides. The purpose of this study is measure erosion rates in an area of bare soil in Putnam County, Tennessee.  Erosion pins consisted of 40-cm-long rebar stakes that were placed into the ground. Forty erosion pins were placed on a plot of land along highway 111 with no vegetation. The distance from the top of each pin to the land surface was measured each month over a 10 month period.  The study site is located on a 30-degree slope and pins were located 2 m apart at both the  bottom of the slope and in the middle of the slope. Along one of the ridges, pins were placed closer together in order to conduct a micro-study where each part of a hill is being examined. Results show that pins near the top of the hill has a 2.5 mm/month erosion rate and the change at the bottom of the hill depends on how much rain has fallen. The results could help other scientists in their study of soil erosion on bare ground.