基于Le Bissonnais法的石漠化区桑树地埂土壤团聚体稳定性研究

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 基于Le Bissonnais法的石漠化区桑树地埂土壤团聚体稳定性研究 DOI: 10.5846/Stxb201305070977 作者: 作者单位: 西南大学资源环境学院,西南大学蚕学与系统生物研究所,西南大学资源环境学院,西南大学动物科技学院,重庆市水土保持生态环境监测总站,西南大学资源环境学院,西南大学资源环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 三峡建设委员会(三峡水库生态屏障区典型经果林生态功能建设与评价研究 2012-2015);国家农业综合开发水土保持重点科技项目(2013);农业部(现代农业产业技术体系专项(CARS-22-ZJ0503)) Study on soil aggregates stability of mulberry ridge in Rocky Desertification based on Le Bissonnais method Author: Affiliation: College of Natural Resources and Environment,Institute of Soil and Water Conservation and Eco-environment,Southwest University,Institute of Sericulture and Systems Biology,Southwest University,College of Natural Resources and Environment,Institute of Soil and Water Conservation and Eco-environment,Southwest University,Faculty of Animal Science and Technology,Southwest University,,College of Natural Resources and Environment,Institute of Soil and Water Conservation and Eco-environment,Southwest University,College of Natural Resources and Environment,Institute of Soil and Water Conservation and Eco-environment,Southwest University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:石漠化区独特的水土流失作用使该区土壤严重退化,地埂植物作为一种独特的农林复合模式对石漠化区土地质量改善和坡耕地土壤生态修复作用明显,能有效保证坡耕地的生态条件和生产性能。选取石漠化区3种不同管理方式的桑树地埂为研究对象,采用传统湿筛(Cаввинов法)和Le Bissonnais法测定土壤团聚体分布与稳定性特征。结果表明:基于Cаввинов法测定的土壤团聚体稳定性以天然林最好,桑埂自然生草地和清草地相对居中,桑埂农地最差;3种管理方式的桑树地埂土壤团聚体稳定性指数(ASI)随地埂距离均表现为ASI90cm > ASI60cm > ASI30cm,主要原因在于桑树地埂对坡耕地土壤团聚体影响的作用范围主要集中在距株30 cm以内,而在地埂30 cm以外田面农耕活动对土壤团聚体结构影响较大,而受桑树地埂影响作用较小。基于Le Bissonnais法快速湿润(FW)处理后土壤团聚体集中分布在0.5-0.25 mm之间,慢速湿润(SW)和湿润振荡(WS)处理后团聚体主要分布在5-1 mm之间。Le Bissonnais法处理后土壤团聚体稳定性表现趋势与Cаввинов法一致,3种处理后的团聚体分形维数D、MWD和GMD均表现为FW < SW < WS。Le Bissonnais法FW和SW处理后团聚体稳定性指标与Cаввинов法达到极显著相关,说明Le Bissonnais法测定石漠化区土壤团聚体稳定性是可行的;石漠化区土壤团聚体稳定性与有机质和粘粒含量呈显著正相关(0.586 ≤ R ≤ 0.864),这说明石漠化区土壤团聚体稳定性是以上两种土壤胶结物质的黏聚作用形成的,且两种土壤胶结物质对土壤消散作用和粘粒膨胀作用引起的团聚体破坏抵抗性强烈,而对低强度机械干扰引起的团聚体破碎没有明显抵抗性,研究结果对石漠化区坡耕地土壤保持具有重要指导意义。 Abstract:Soil aggregate is the basic unit of soil structure, and its stability is closely related to soil erosion-resistance. Soil and water loss makes the soil degradation severer in the specific rocky desertification area. Ridge plant, one of the special agroforestry pattern, plays important roles in improving soil quality and ecological restoration of slope land in rocky desertification area. Qianjiang is a typical rocky desertification area in Chongqing, where mulberrywas widely planted and becomes one of the main economic forest and ridge plants. In order to explore the stability mechanism of soil aggregate, mulberry ridges with three different management modes were selected in this study. The distribution and stability of soil aggregates were measured by traditional Cаввинов method and Le Bissonnais method. The results showed that the stability of soil aggregates based on Cаввинов methods was the best in natural forest land, followed by natural grassland and weeded land, and was the worst in farmland. The aggregate stability index (ASI) followed the order of ASI90cm > ASI60cm > ASI30cm in the three management models. The R0.25 water stable aggregate increased with increasing distances from ridge, while the aggregate destruction rate (PAD) decreased. The possible reason might be as follows: The effects of mulberry ridge on soil aggregates mainly cover areas within 30 cm, while the agricultural cultivation greatly influenced soil aggregates structure in areas beyond 30 cm with little effect from the ridge. Based on Le Bissonnais methods, the majority of aggregates were broken down to small aggregates by fast wetting (FW) treatment. The distribution of soil aggregates was in the category of 0.5-0.25 mm with diameter after FW, and 5-1 mm after SW and WS. The fractal dimensions (D) of aggregates was the highest (2.53) after FW and the lowest after WS (2.33). The changes of soil aggregates stability with Le Bissonnais and Cаввинов method were similar. The fractal dimensions (D), mean weight diameter (MWD) and geometrical mean diameter (GMD) presented the trend of FW < SW < WS, which indicates that the collapse mechanism of soil aggregates was the air pressure dissipation after fast wetting, followed by clay expansion, and the mechanical vibration in rocky desertification area. MWD with Le Bissonnais method was positively correlated with ASI, R0.25, MWD and GMD from Cаввинов method and negatively correlated with PAD and Dwet-dry values. The results indicated that Le Bissonnais method was feasible in measuring soil aggregates stability in rocky desertification area. The soil aggregates stability was positively correlated with the contents of clay and soil organic matter in rocky desertification area (0.586 ≤ R ≤ 0.864), indicating that the soil aggregates stability might be formed by cohesive forces of the soil cementing matters. The cementing matters had strong resistance to the collapse process of soil aggregates caused by soil dissipation and clay expansion, while had no obvious resistance to the collapse process caused by mechanical vibration. Therefore, in ecological restoration and agricultural activities, plant species should be chosen according to the criteria of improving soil organic carbon, soil texture and increasing clay content in short period in rocky desertification area. The results had important roles in conserving cultivated soils in rocky desertification area. 参考文献 相似文献 引证文献