Submitted to: Catena
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/1/2004
Publication Date: 6/20/2005
Citation: Ritchie, J.C., Nearing, M., Nichols, M., Ritchie, C.A. 2005. Patterns of soil movement on Lucky Hills Watershed, Walnut Gulch Arizona. Catena 61(2-3):122-130. Interpretive Summary: Soil erosion rates and patterns were estimated for the Lucky Hills Watershed, a subwatershed of the Walnut Gulch Experimental Watershed in southeastern Arizona, from measurements of the distribution of fallout Cesium-137. Net soil loss had occurred at 54 of the 74 sample sites or approximately 73% of the watershed showing wide spread soil loss on the watershed. Soil erosion rates were significantly correlated the percent of rock fragments in the surface 25-cm soil layer with soil erosion increasing as rock fragments decreased. This study supports earlier research on Walnut Gulch Experimental Watershed that showed the importance of rock fragments in estimating soil loss. Vegetation cover at a sample site was not related to soil erosion at the site. The study shows the importance of understanding soil surface properties (i.e., rock fragments, cover) for determining soil erosion patterns. With such information managers will be better able to design plans to slow soil degradation in arid and semiarid rangelands.
Technical Abstract: Degradation of semiarid and arid rangelands is a major concern and is usually described in terms of soil erosion and changing plant communities. The purpose of this paper was to determine the patterns and rates of soil erosion and redistribution from measurement of the distribution of fallout Cesium-137 on the Lucky Hills Watershed, a semiarid rangeland watershed in southeastern Arizona. Soil redistribution ranged from the soil loss of '9.8 mt/ha/yr to soil deposition of +7.0 mt/ha/yr- Net soil loss occurred at 54 of the 74 sample sites or approximately 73% of the watershed. Soil erosion rates were significantly correlated to the percent of rock fragments in the surface 25-cm soil layer but were not correlated with vegetation cover at the sample site. This study supports earlier research on Walnut Gulch Wathershed that showed the importance of rock fragments in estimating soil loss.