不同土地利用方式对红壤坡地土壤阳离子交换量及交换性盐基离子的影响

摘要

With the red soil developed from quaternary red clay as the research object, this paper studied the distribution of soil cation exchange capacity (CEC) and exchangeable base cations under different land use patterns, including krasnozem waste land (WL), upland ( UL) , orchard ( OR) and tea garden ( TG) in the sloping farmland of red soil, and the influencing factors on soil cation ex-change capacity ( CEC) and exchangeable base cations were discussed.Result showed that:(1) The soil CEC in the study area ranged from 13.48 to 16.31 cmol・kg-1 , indicating that its nutrient-holding capability was at a moderate level;there was no significant differ-ence in soil cation exchange capacity ( CEC); the soil clay had a great contribution to soil cation exchange capacity ( CEC) ( p>0.05).(2) The total exchangeable base (TEB) content ranged from 1.73 to 5.01 cmol・kg-1, and the size order of exchangeable base cations was Ca2+>Mg2+>K+>Na+;the content of exchangeable base cations differed significantly under different land use pat-terns (p<0.05), and their content was higher in upland and orchard than in that of tea garden and krasnozem waste land;except for orchard 0~10 cm soil layer, exchangeable Ca2+and Mg2+content was lower than that of 10 cm~40 cm soil layer and exchangeable K+and Na+showed an opposite trend;soil clay was the major factor contributing to exchangeable Ca2+and Mg2+, and soil organic matter and clay had a little influence on exchangeable K+and Na+.(3) The base saturation percentage ( BSP) ranged from 4.33 to 19.86%, illustrating that soil fertility level was lower;the base saturation percentage ( BSP) was different significantly among land use patterns ( p<0.05);the base saturation percentage ( BSP) had no significant effects on pH value ( p>0.05) .%文章以第四纪红粘土母质发育的红壤为研究对象，研究了红壤荒坡地（ WL）、红壤旱地（ UL）、红壤坡地茶园（ TG）和红壤坡地果园（ OR）4种土地利用方式下红壤坡地土壤土壤阳离子交换量（ CEC）和交换性盐基离子的分布规律，并初步探讨了土壤CEC和盐基离子的影响因素，结果表明：（1）研究区土壤CEC介于13．48 cmol・kg－1～16．31 cmol・kg－1，保肥能力中等；不同土地利用方式下土壤CEC差异不显著（ p＞0．05）；土壤粘粒对土壤CEC贡献较大。（2）该区土壤交换性盐基总量（ TEB）介于1．73 cmol・kg－1～5．01 cmol・kg－1，交换性盐基离子的含量呈现出Ca2＋＞Mg2＋＞K＋＞Na＋的规律；不同土地利用方式下土壤交换性盐基离子的含量差异显著（p＜0．05），以红壤旱地和红壤坡地果园整体较高，红壤坡地茶园最低；除红壤坡地果园外，土壤交换性Ca2＋、 Mg2＋含量均表现为0～10 cm低于10 cm～40 cm土层，而土壤交换性K＋、 Na＋具有一定的表聚性；土壤粘粒对土壤交换性Ca2＋、 Mg2＋含量的贡献较大，而对土壤交换性K＋、 Na＋的影响较小。（3）该区土壤盐基饱和度（BSP）介于4．3％～19．9％，土壤肥力水平较低；不同土地利用方式下土壤BSP差异显著（p＜0．05）；土壤BSP对pH影响不显著（ p＞0．05）。图2，表2，参20。