喀斯特山区不同生态恢复模式土壤盐基离子的交换及分布特征  

Exchange and Distribution Characteristics of Soil Base Ions Under Different Ecological Restoration Pattern in the Karst Mountainous Area

作　　者：陈忠柳 舒英格[1] 周鹏鹏 CHEN Zhongliu;SHU Yingge;ZHOU Pengpeng(College of Agricultural, Guizhou University, Guiyang 550025)

机构地区：[1]贵州大学农学院,贵阳550025

出　　处：《水土保持学报》2020年第4期304-311,319,共9页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(31460133)。

摘　　要：为了解喀斯特山区生态恢复模式对土壤盐基离子的交换及分布特征的影响,以喀斯特山区典型黄色石灰土为对象,研究了耕地、草地、林草间作地、退耕还草地生态恢复模式下土壤阳离子交换量(CEC)和盐基离子的分布规律。结果表明:该区土壤CEC为26.52~44.90 cmol/kg,且基本随土层深度的增加逐渐减小;各土壤层次阳离子交换量均表现为退耕还草地显著低于其他生态恢复模式(P<0.05);在0—10,10—20 cm土层中林草间作地的CEC最高。交换性盐基离子的含量呈现出Ca2+>Mg2+>K+>Na+的规律,且以Ca2+、Mg2+为主(占TEB的比例平均为91.92%,6.04%),K+、Na+所占TEB比例较低(平均为1.03%,1.01%);盐基离子中交换性K+、Na+、Mg2+含量具有表聚性,基本随土层深度的增加而逐渐下降;不同生态恢复模式下,退耕还草地各盐基离子含量显著低于林草间作地、耕地和草地(P<0.05),但各盐基离子含量随土层深度不同存在较大差异。土壤交换性盐基总量(TEB)在剖面层次上的分布规律不明显,不同生态恢复模式土壤TEB大小顺序随着土层深度的加深有所不同,在0—10,10—20 cm土层和40—60 cm(母岩)层均表现为草地最高,退耕还草地最低。土壤盐基饱和度(BS)为42.58%~65.02%,且随土层深度的增加逐渐增大,各土壤层次BS均表现为草地>耕地>林草间作地>退耕还草地;相关分析表明,CEC、盐基离子含量与有机质、全氮和碱解氮均呈极显著正相关。冗余分析表明,土壤理化因子仅能解释45.3%的阳离子交换作用变化,土壤阳离子交换作用变化除了受土壤基本理化因子的影响外,还受其他因素的影响。总体而言,退耕还草地在供肥保肥和缓冲能力上显著低于其他恢复模式,土壤供肥保肥和缓冲性能在恢复初期退耕还草阶段有所下降,但随着生态恢复的进程会逐渐得到改善。In order to understand the influence of ecological restoration models on the exchange and distribution of soil base ions in the karst mountain area,the typical yellow rendzina was taken as study object and the effects of ecological restoration pattern,which including arable land(AL),Grassland(GL),the intercropping system of forest and grass(ICS),and the grassland converted from cropland(CGL),on the cation exchange capacity(CEC)and the exchangeable base contents were studied.The results showed that the CEC vary between 26.52 and 44.90 cmol/kg and decreased with the increase of profile depth.CEC of each soil layer was significantly lower in CGL than in ICS,GL,and AL(P<0.05).The CEC of ICS was the highest in 0—10 cm and 10—20 cm soil layers.The size order of exchangeable base cations was Ca2+>Mg2+>K+>Na+,and Ca2+,Mg2+were the major exchangeable bases,because Ca2+,Mg2+,K+,and Na+accounts for 91.92%,6.04%,1.03%,and 1.01%of the total content of exchangeable bases,respectively.The contents of Mg2+,K+,and Na+were higher in the surface layer than those in deeper layers and decreased with the increase of soil depth regardless of restoration patterns.Under different ecological restoration modes,the content of each base ion in CGL was significantly lower than in ICS,Al and GL(P<0.05),but the content of each base ion varied with the soil depth.The distribution rule of soil total exchangeable base(TEB)was not obvious at the soil depth.The order of soil TEB in different ecological restoration modes was different with the increase of profile depth,in 0—10 cm,10—20 cm soil layer,and 40-60 cm(mother rock)layer,GL was the highest and CGL was the lowest.The soil base saturation(BS)in this area changed between 42.58%and 65.02%and gradually increased with the increase of soil depth.BS were the largest in GL,and followed by those in AL,ICS,and CGL.Correlation analysis showed that CEC,base ion content and organic matter,total nitrogen and alkaline nitrogen were all significantly and positively correlated.Redundancy analysis(RDA)

关 键 词：喀斯特山区 生态恢复模式 土壤盐基离子 剖面分布 

分 类 号：S153.61[农业科学—土壤学]