Abstract: Soil erosion is one of the most serious environmental problems in China, which has brought  huge impact on ecology and human development. Owing to the close correlation between 137Cs redistribution in soil and soil erosion migration, this paper took it as a tracer and studied the soil erosion and accumulation to calculate the soil erosion rate, space distribution, and also the spatial distribution of soil erosion and spatial distribution of soil migration. This paper adopted 137Cs tracer technology to study soil erosion in Tong Mountain area, and further explored the effects of soil erosion on soil nutrients. The background value of 137Cs in the study area was 1 732.48 Bq/m2. With the increase of soil depth, the mass concentration of 137Cs decreased logarithmically. The 137Cs content in the study area ranged from 787.62 Bq/m2 to 2 380.96 Bq/m2. Soil deposit and soil erosion occurred in the study area at the same time. The 137Cs content in forest land was the highest, followed by bamboo grove and tea plantation. The distribution of TN, TP and SOC in different types of land was also different. There was a very significant linear positive correlation between SOC and 137Cs, but there was no significant correlation between 137Cs and TN and TP. Erosion had the most significant effect on soil surface. Compared with the background area, the 137Cs and SOC at soil surface layer (0~5 cm) both in the erosion and deposition areas had obvious losses, reaching 31%, 17% and 45%, 29%, respectively. The results showed that the soil erosion resistance of woodland was stronger than that of tea garden and bamboo forest. In the process of soil erosion, distribution of SOC, TN and TP would be influenced by soil redistribution with different degrees. Influence on SOC was the strongest. The effect of soil erosion at soil surface layer was the most obvious, the upper soil layer was usually the most concentrated place for nutrient. Therefore, soil erosion would cause soil nutrients loss and pollute down stream and rivers. Many agricultural and environmental problems were worthy of attention.

Key words: isotopic trace, soil organic matter, total nitrogen, total phosphorus

摘要： 土壤侵蚀是中国最严重的环境问题之一，给生态和人类发展带来极大的影响。137Cs在土壤中的再分配和侵蚀小区土壤的运移之间紧密相关，用它做示踪剂可推算出土壤侵蚀的速率和空间分布，以及研究土壤侵蚀的空间变化和土壤迁移的空间分配。采用137Cs示踪技术对铜山地区的土壤侵蚀进行了研究，并进一步探讨了土壤侵蚀对土壤养分造成的影响。研究区137Cs的背景值为1 732.48 Bq/m2，随着土壤深度的增大，137Cs质量浓度呈对数下降的趋势。该研究区137Cs含量的范围是787.62~2 380.96 Bq/m2，土壤沉积和土壤侵蚀同时发生在研究区内，林地中137Cs含量最高，其次是竹林和茶园。TN、TP和SOC在不同用地类型中的分布也有差异。SOC与137Cs呈极显著的线性正相关，而137Cs与TN、TP之间相关性不显著。侵蚀运动对于土壤表层的影响最为显著，与背景区相比，侵蚀区和沉积区土壤表层（0~5 cm）的137Cs和SOC都有明显的损失，分别达到了31％、17％和45％、29％。研究结果表明：①林地抵抗土壤侵蚀的能力相较于茶园和竹林更强；②土壤侵蚀过程中土壤再分配对SOC、TN和TP的分布都会产生不同程度的影响，其中对于SOC的影响最强烈；③土壤侵蚀对于土壤表层的影响最为显著，土壤上层通常是养分最为集中的地方，因此土壤侵蚀造成的土壤养分的流失以及富集养分的径流污染下游河流，引起很多农业环境问题都值得被关注。

关键词: 同位素示踪, 土壤有机质, 全氮, 全磷