中文摘要：

选取江西余江县小流域的旱耕地与水稻田作为研究区，利用137^Cs技术示踪红壤耕地的土壤侵蚀。由于耕作措施的混合作用，137^Cs均匀分布在耕层深度内，且绝大部分含量集中在旱耕地和水田表层的18和27cm以内;采用了杨浩的土壤侵蚀模型得到了50a以来不同土地利用方式下的土壤侵蚀速率。结果表明，非耕地土壤侵出速率为2953t·km^-2·a^-1〉旱耕地960t·km^-2·a^-1〉水稻田840t·km^-2·a^-1;水田比旱耕地更有利于水土保持，微地貌是影响研究区内部土壤侵蚀的主要因素;利用周维芝模型和杨浩模型得到的结果基本一致，都能反映土壤侵蚀的强度和空间分布。137^Cs技术不仅用来示踪不同土地类型上50a来的土壤侵蚀速率和空间分布，而且为评价不同水土保持措施提供一种很好的方法。

英文摘要：

The soil erosion rates on agricultural land in the red soil were evaluated using 137^Cs technique, two sites under different land use （dry farmland and paddy field） in Yujiang County, Jiangxi Province, Southern China, were sampled to reveal the spatial variation of soil erosion. The total 60 sampling points were collected to estimate soil redistribution rates from measurement of the 137^Cs inventories of soil samples at the two sites using Mass Balance Model. The depth distribution of 137^Cs within the soil profiles was shown uniform due to tillage measurement, and the majority of 137^Cs was constrained in the top 18 and 27 cm of the soil profiles, respectively. Soil erosion rates on different lands were as follow： 2 953 t·km^-2·a^-1 on uncultivated land〉960 t·km^-2·a^-1 on dry farmland〉840 t·km^-2·a^-1 on paddy field since 1954.Terrace was a more effective measurement of soil conservation than dry farmland. Micro-topography was a major factor affecting erosion rates in the interior of catchment. The results determined by models of ZHOU Weizhi and YANG Hao were similar and could reflect the intensities and distribution. The 137^Cs technique provided not only the average soil erosion rates on different land use and spatial distribution during 50 years, but also provided a good method for assessing different soil conservation measurements in southern China.