The estimation of erosion and sediment delivery rates in tropical mountain watersheds is dicult and most of the methods widely used for estimating soil erosion over large areas have serious limitations. The 137 Cs approach has potential for quantifying soil erosion because it can provide retrospecti
Caesium-137 estimates of erosion in agricultural areas
β Scribed by R. A. Sutherland
- Book ID
- 102861899
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 784 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0885-6087
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β¦ Synopsis
Abstract
Sediment redistribution within nearβlevel agricultural fields in the Gray Wooded soil zone of Saskatchewan was studied using the artificial environmental tracer caesiumβ137 (^137^Cs). the objective of this study was to estimate erosion rates caused by wind erosion, and land clearing techniques (i.e. bulldozing). Net rates of erosion and deposition were quantified over the past 30 years on three fields. Wind erosion was estimated to be approximately 1.0 t ha^β1^ y^β1^ on a nearβlevel field, with 50 per cent of the sampling sites having erosion rates in excess of soil formation. Bulldozing produced median net sediment flux values of between 40 and 90 t ha^β1^ y^β1^. in addition, between 65 and 85 per cent of the sampling sites had erosion rates in excess of the maximum tolerable limit (i.e. 11.0 t ha^β1^ y^β1^). These results indicate significant accelerated erosion results from land clearing techniques used in central Saskatchewan. Bulldozing of the fields removed the LFHβhorizon and exposed the underlying mineral horizon. Bulk densitites of the 0 to 15 cm layer in the cleared fields were 27 to 55 per cent greater than the comparable depth increment within the undisturbed forest site. Organic carbon concentrations within the 1930s, 1979, and 1987 fields were decreased by 47, 42, and 37 per cent, respectively following cultivation and bulldozing. Decreases in total nitrogen for the cultivated fields ranged from 33 to 38 per cent.
π SIMILAR VOLUMES
## Measurements are reported of the distribution of "'Cs within a 6.6 ha drainage basin on cultivated black earth soils located near Merriwa in New South Wales (N.S.W.). The results were used to estimate net loss as well as accumulation of soil. The losses of "'Cs from the catchment slopes were as