|
|
seeKSpace >
中国西部环境和生态科学研究计划 >
2002年资助项目 >
长江上游山地冲沟格局发生演化对土地利用变化的反应 >
科学论文 >
Please use this identifier to cite or link to this item:
http://hdl.handle.net/2239/1680
|
| Title: | 强度耕作对~(137)Cs、~(210)Pb_(ex)和有机质剖面分布的影响 |
| Authors: | Li, Yong(李勇)
Bai, Lingyu(白玲玉)
Zhang, Xingchang(张兴昌)
Lindstrom M L
Bork H R |
| Keywords: | 137Cs(~（137）cesium （~（137）Cs）)
210Pbex(unsupported ~（210）lead （ ~（210）Pb_（ex））)
土壤有机质(soil organic matter)
剖面变异(profile variation)
耕作侵蚀(tillage erosion) |
| Issue Date: | Sep-2003 |
| Publisher: | 《水土保持学报》2003，17（3）：1-4. |
| Abstract: | [中文摘要]：很少有关于直接测定强度耕作侵蚀引起土壤退化过程的报道。我们的目的是确定应用137Cs和210Pbex直接定量评价耕作侵蚀对土壤有机质(SOM)坡面运移影响的可能性。我们在黄土高原陡坡耕地上进行了50次犁耕活动,并将与其相临的另一块陡坡耕地作为对照。在对照坡地不同坡位,137Cs浓度均匀分布于上部0～30cm土层,而210Pbex浓度在坡上部和坡中部随土层深度增加呈现线性递减,在坡下部呈指数函数递减。0～30cm土层中土壤有机质含量显著大于30cm深度以下土层,并在坡中部和坡下部呈现与210Pbex类似的土壤剖面分布特征。与对照坡地比较,50次犁耕活动导致坡上部、坡中部0～45cm土层的SOM含量分别降低了38%和47%,坡下部0～100cm土层中的SOM含量却提高了18%。坡上部土壤剖面中137Cs浓度的加权平均值从1.48Bq/kg降低到0.29Bq/kg,坡中部从2.53Bq/kg减少到0.33Bq/kg,坡下部从1.48Bq/kg提高到2.81Bq/kg。210Pbex浓度的剖面加权平均值在坡上部从27.71Bq/kg下降到6.15Bq/kg,在坡中部和坡下部分别从35.46Bq/kg和25.53Bq/kg降低到1.57Bq/kg和19.40Bq/kg。137Cs和210Pbex的剖面分布与SOM在p<0.001水平呈显著相关,相关系数R2值在对照坡地为0.81～0.86,在犁耕实验坡地为0.86～0.91。实验结果表明,环境放射性核素137Cs和210Pbex在黄土高原陡坡地遵照同一物理运移机理,可直接应用于定量评价耕作侵蚀与土壤质量的关系。
[英文摘要]：Few direct measurements have conducted to investigate the dynamic process of soil degradation as affected by intensive tillage at the field level. Our objective is to test the potential of 137Cs and 210Pbexfor directly assessing the movement of SOM on the slope land as affected by tillage operations. We conducted 50 plowing operations over a 5day period using a donkeydrawn moldbordplow on steep backslope of the Chinese Loess Plateau. Profile variations of 137Cs, 210Pbex and SOM contents were measured at upper, mid, and lower portion of the slope after 50 plowing operations. Intensive tillage effects on 137Cs, 210Pbex and SOM contents were determined from a control slope adjacent to experimental slope. 137Cs concentration was uniformly mixed in the upper 0~30 cm of soil whereas 210Pbex showed a linear decrease at upper and mid portion, and an exponential decrease with depth on the lower portion of the control slope. SOM contents of 0~30 cm layers were much higher than the soil layers below 30 cm on the control slope, and show ed a similar decrease pattern to profile pattern of 210Pbex on the m id and lower portion of the control slope. Fifty 50-plowing operations resulted in a decrease of SOM content (g/kg) by 38% and by 47% for the soil layers of 0～45 cm at upper portion and mid portion, respectively. How ever, the lower position showed an increase of SOM content by 18% in the soil layers of 0～100 cm after 50 p lowing operations. Weighed mean values of 137Cs concentrations decreased from 1. 48 Bq/kg to 0. 29 Bq/kg at upper position, from 2. 53 Bq/k g to 0. 33 Bq/k g at m id position, and increased from 1. 48 Bq/k g to 2. 81 Bq/kg at lower position. Weighed mean values of 210Pbex concentrations decreased from 27. 71Bq/k g to 6. 15Bq/kg at upper position, from 35. 46Bq/k g to 1. 57Bq/k gatm id position, and from 25. 53 Bq/kg to 19. 40Bq/k gat lower position. Profile concentrations of 137Cs and 210Pbex are significantly correlated with SOM contents with R 2 values of 0. 81～0. 86 for control slope, and 0. 86～0. 91 for experimental slope. Our results suggested that fallout 137Cs and 210Pbex could be used directly for quantifying soil quality-soil redistribution relationship as affected by tillage erosion. |
| URI: | http://seekspace.resip.ac.cn/handle/2239/1680 |
| Appears in Collections: | 科学论文
|
Files in This Item:
| File |
Description |
Size | Format |
|---|
| 强度耕作对～137Cs～210Pb_ex和有机质剖面分布的影响.PDF | | 239Kb | Adobe PDF | View/Open |
|
All items in DSpace are protected by copyright, with all rights reserved.
|
