TITLE:
Soil Organic Carbon Dynamics in Eroding and Depositional Landscapes
AUTHORS:
Kenneth R. Olson, Mahdi Al-Kaisi, Rattan Lal, Larry Cihacek
KEYWORDS:
Soil Organic Carbon, Erosion, Monitoring
JOURNAL NAME:
Open Journal of Soil Science,
Vol.6 No.8,
August
31,
2016
ABSTRACT: As a requisite to determining management practice effects on stored soil
organic carbon (SOC) stock in a landscape unit, the baseline SOC stock with
depth must be determined and the land use, management practices and erosion-induced
changes measured periodically or over a period of time. The SOC loss and
additions due to soil erosion, transport and deposition must be accounted for
or be quantified when determining the real impact of the management practices
on net SOC stock over time. Quantifying the SOC loss due to erosion will help
avoid over estimation of the management practice performances. Appropriate soil
sampling designs and sampling procedures are needed to establish a SOC stock
baseline and to monitor and verify new SOC storage or sequestration as a result
of a management practice. The Dinesen Prairie landscape in western Iowa, USA
was sampled to provide a SOC stock baseline and then the adjacent cropland was
sampled to determine the past impact of land use change, management practices
and erosion on SOC stock retention. After 100 to 150 years of farming, the
entire cropland landscape retained only 49% of the baseline prairie SOC stock.
Only the cropland toe-slope (TS) retained more SOC stock than the prairie TS as
a result of the erosion, transport and deposition of SOC rich sediment on the
TS.