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Assessment of erosion rates and patterns from spatial variability of cesium-137
Abstract
Soil erosion predictions and mapping of erosion patterns are important for developing the corresponding management strategies to deal with soil erosion. This research was conducted; (i) to determine cesium sorption and desorption characteristics in soils, (ii) to develop a depth dependent model for predicting soil erosion from $\sp{137}{\rm Cs}$ activity, and (iii) to define erosion patterns from measurements of the spatial distribution of $\sp{137}{\rm Cs}$ within the field. Cesium sorption was more in soils with high clay or low sand content and neutral pH than soils with low clay or high sand content and having relatively acidic soil reaction. A significant relationship was also found between the sorption of Cs and soil organic-C content. Results indicate that Cs is strongly retained against exchange with Ca and Na in soils, but this degree of retention against exchange with K depends on the type of dominant clay mineral. A depth dependent model, polynomial method, was developed and used to predict soil erosion from the research field. The model accounts for initially higher rates of $\sp{137}{\rm Cs}$ loss due to heterogeneity in mixing of $\sp{137}{\rm Cs}$ in tillage layer for the first several years of cultivation. Furthermore, erosion rates estimated by the polynomial method do not depend on the depth of tillage, thus intermittent changes in cultivation practices and tillage depth do not influence erosion predictions. Annual estimated erosion rate using the polynomial method was 47.5% lower than the proportional method, but equivalent to the USLE. Mapping of soil erosion patterns from the spatial variability of $\sp{137}{\rm Cs}$ indicated that greater than 97% of this field had eroded at a rate 2.5 times the soil loss tolerance for at least 27 years. Resulting erosion patterns can provide useful information that can contribute to our understanding of soil erosion processes. Subsequently this data can be used to help refine erosion control guidelines which influence the selection of a vast array of management practices by an agricultural producer including; tillage, fertilizer application, crop rotation, plant population, and structures.
Subject Area
Agronomy|Agricultural engineering|Statistics
Recommended Citation
Oztas, Taskin, "Assessment of erosion rates and patterns from spatial variability of cesium-137" (1993). ETD collection for University of Nebraska-Lincoln. AAI9415988.
https://digitalcommons.unl.edu/dissertations/AAI9415988