耕作对河套黄灌区典型盐碱土水稳定性团聚体及有机碳和全氮含量的影响  

Effects of cultivation on water-stable aggregates and their organic carbon and nitrogen in typical saline-alkali soil of Hetao Yellow River irrigation region

作　　者：章征程 林启美[1] 李谟志[1] 李贵桐[1] 赵小蓉[1] ZHANG Zhengcheng;LIN Qimei;LI Mozhi;LI Guitong;ZHAO Xiaorong(College of Resources and Environment,China Agricultural University,Beijing 100193,China)

机构地区：[1]中国农业大学资源与环境学院,北京100193

出　　处：《南京农业大学学报》2018年第6期1085-1092,共8页Journal of Nanjing Agricultural University

基　　金：国家重点研发计划项目(2016YFC0501306)

摘　　要：[目的]本文旨在探讨耕作对河套灌区典型盐碱土水稳定性团聚体及其有机碳和全氮含量的影响。[方法]选择河套黄灌区典型的5种盐碱土,用Yoder湿筛法测定水稳定性团聚体,再用元素分析仪测定有机碳和总氮含量。[结果]河套黄灌区典型盐碱土主要是53～10μm团聚体,占55.84%～79.72%,平均68.10%;其次是250～53μm团聚体,占11.79%～29.18%,平均17.95%;而>250μm和<10μm团聚体平均不超过5.21%,但不同盐碱土差异非常大。耕作增加了53～10μm团聚体数量,减少了>250μm和250～53μm团聚体数量。>250μm和<10μm团聚体的有机碳和全氮含量比较高,有机碳含量平均分别为8.38和6.81 g·kg^(-1),全氮含量平均分别为0.98和1.04 g·kg^(-1),但由于这部分粒级团聚体的质量分数较高,有机碳和全氮主要分布在53～10μm团聚体中。大团聚体质量分数与土壤有机碳和全氮含量呈显著正相关关系,而小团聚体质量分数与EC、pH及Na+、SO2-4、Cl-和CO2-3呈显著正相关关系。[结论]耕作降低了大部分土壤中各粒级团聚体有机碳和全氮含量,促进了有机碳和全氮从大团聚体向小团聚体转移。盐分决定盐碱土小团聚体的数量,而有机物质在大团聚体形成中起重要的作用。河套地区盐碱土改良,应在降低盐分的同时加大有机物质投入量。[Objectives]This study was aimed to explore the effects of cultivation on water-stable aggregates and their organic carbon and totalnitrogen contents of the typical saline-alkaline soils in Hetao Yellow River irrigation region.[Methods]Five typical saline-alkali soils in this area were selected in this study.Different waterstable aggregates were separated by Yoder’s wet sieve method.The organic carbon and total nitrogen in the obtained soil aggregates were determined using a Elemental Vario ELⅢanalyzer.[Results]The results showed that the typical saline-alkali soils in Hetao Yellow River irrigation region were dorminant in 53-10μm aggregates,accounting for 55.84%-79.72%,with an average of 69%;following by 250-53μm aggregates,accounting for 11.79%-29.18%,with an average of 17.95%.Both>250μm and<10μm aggregates were evenly less than 5.21%,quite different among the tested saline-alkali soils.Cultivation induced increases of 53-10μm aggregates but reduction in both>250μm and 250-53μm aggregates.Both>250μm and<10μm aggregates contained high organic carbon and total nitrogen,8.38 g·kg^-1 and 6.81 g·kg^-1 organic carbon,and 0.98 g·kg^-1 and 1.04 g·kg^-1 total nitrogen on average respectively.However,due to their high mass fraction,the 53-10μm aggregates contributed most organic carbon and total nitrogen in the wholes.There was a significant positive correlation between the mass fractions of macroaggregates and soil organic carbon and total nitrogen,while the mass fractions of micro-aggregates were positively correlated with the values of EC,pH and Na^+,SO^2-4,Cl^-,and CO^2-3.[Conclusions]Cultivation results in reduction of organic carbon and total nitrogen of all the aggregates from most soils and promoted the transfer of organic carbon and total nitrogen from macroaggregates to microaggregates as well.Salinity determines the aggregation of small aggregatesin saline-alkali soils while organic matter may play an important role in the formation of large aggregates.Therefore,reducing salt content together

关 键 词：河套黄灌区 盐碱土 耕作 水稳性团聚体 有机碳 全氮 

分 类 号：S152.4[农业科学—土壤学]