ORCID
- Blake, Will: 0000-0001-9447-1361
Abstract
Land use conversion is generally accompanied by large changes in soil organic carbon (SOC). SOC influences soil erodibility through its broad control on aggregate stability, soil structure and infiltration capacity. However, soil erodibility is also influenced by soil properties, clay mineralogy and other human activities. This study aimed to evaluate soil organic carbon as proxy of soil erosion risk in the Nyumba ya Mungu (NYM) catchment in Northern Tanzania. Soil organic carbon (SOC) was measured by an AgroCares scanner from which the soil organic matter (SOM) was derived using the conversional van Bemmelen factor of 1.72. A regression analysis performed between the measured loss on ignition (LOI) values and SOM from the AgroScanner showed a strong positive correlation in all land use classes (LOIFL R2 = 0.85, r = 0.93, p < 0.0001; LOICL R2 = 0.86, r = 0.93, p = 0.0001; LOIGL R2 = 0.68, r = 0.83, p = 0.003; LOIBS R2 = 0.88, r = 0.94, p = 0.0001; LOIBL R2 = 0.83, r = 0.91, p = 0.0002). This indicates that SOC from the soil scanner provided a good representation of the actual SOM present in soils. The study also revealed significant differences in the soil aggregate stability (WSA) and SOM stock between the different land use types in the Upper Pangani Basin. The WSA decreases approximately in the following order: grassland > forest land > bare land > cultivated > bush land. Land use change can thus potentially increase the susceptibility of soil to erosion risk when SOC is reduced. Since WSA was directly related to SOM, the study indicates that, where formal measurements are limited, this simple and inexpensive aggregate stability test can be used by farmers to monitor changes in their soils after management changes and to tentatively assess SOC and soil health.
DOI
10.3390/earth2040045
Publication Date
2021-10-15
Publication Title
Earth
Volume
2
Issue
4
Embargo Period
2022-02-16
Organisational Unit
School of Geography, Earth and Environmental Sciences
First Page
764
Last Page
780
Recommended Citation
Amasi, A. I., Wynants, M., Kawala, R., Sawe, S., Blake, W., & Mtei, K. (2021) 'Evaluating Soil Carbon as a Proxy for Erosion Risk in the Spatio-Temporal Complex Hydropower Catchment in Upper Pangani, Northern Tanzania', Earth, 2(4), pp. 764-780. Available at: https://doi.org/10.3390/earth2040045
