|Hao, Y - OHIO STATE UNIVERSITY|
|Lal, R - OHIO STATE UNIVERSITY|
|Izaurralde, R - PACIFIC NW NATIONAL LAB|
Submitted to: Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 10, 2001
Publication Date: N/A
Interpretive Summary: This study shows that land use has a significant impact on soil and soil organic carbon (SOC) erosion. By using fallout radioactive Cs-137 to estimate soil erosion a retrospective measurement of soil and SOC erosion can be estimated for different land treatments. If we assume that predictions of soil and SOC erosion is best done by the sedimentation method involving long-term measurement using a flume and water stage recorder, then erosion estimated by the Cs-137 method (1 to 3 times higher than the sedimentation method) can be a good estimator retrospectively. In this study, erosion rate predicted by RUSLE was 3 to 14 times the sediment measurements. Therefore, long-term soil erosion rates estimated using the Cs-137 method can provide a valuable resource for understanding soil and SOC erosion where other data are not available.
Technical Abstract: The effect of agricultural land use on soil and soil organic carbon (SOC) erosion was assessed at the North Appalachian Experimental Watershed Research Station for the period from 1951 to 1998. The agricultural land use included plow till corn-wheat-meadow-meadow (CWMM) rotation from 1951 to 1970, plow till continuous corn (CC) from 1971 to 1975, meadow (M) from 1976 to 1983, and no till corn-soybean (CS) rotation from 1984 to 1998. Soil erosion was assessed by long term sediment collection, the Revised Universal Soil Loss Equation (RUSLE), and the Cesium-137 method. The SOC erosion was computed as a product of the soil erosion multiplied by the SOC content of 1.51% in the surface soil, and by the SOC enrichment ratio of 1.71. Sediment measurements indicated that the annual soil and SOC erosion (Mg/ha/yr) were, respectively, 1.55 and 0.040 for CWMM, 5.88 and 0.15 for CC, 0.63 and 0.016 for CS, 2.34 and 0.060 for all the corn years, 0.35 and 0.009 for the plow till CWMM wheat-year, and essentially zero for all the meadow years. The annual soil and SOC erosion (Mg/ha/yr) for the cropping rotation periods were, respectively, 0.50 and 0.013 for CWMM, 5.88 and 0.15 for CC, 0.63 and 0.016 for CS, and 1.02 and 0.026 for the entire study period. In comparison with the measurement of soil and SOC erosion by the sedimentation method, the estimates were 3 to 14 times higher by the RUSLE, 10 to 55 times higher by the proportional equation using Cs-137, and 1 to 3 times by the revised exponential equation using Cs-137.