西宁盆地4种草本和灌木植物降盐效应试验研究

以西宁盆地长岭沟流域自建试验区为研究区,筛选出适宜当地气候条件下生长的2种灌木植物柠条锦鸡儿(Caragana korshinskii Kom.)、霸王[Zygophyllum xanthoxylon(Bunge)Maxim.]和2种草本植物细茎冰草(Agropyron trachycaulum cv.Slender)、紫花苜蓿(Medicago sativa Linn.)作为试验供试种,在试验区对4种植物采用单一种植和组合种植方式,探讨2种种植条件下植物根系在边坡地表以下垂直方向土体中K^+、Ca^2+、Na^+、Mg^2+、SO4^2-、Cl^-、HCO3^-、CO3^2-等8种易溶盐离子含量及其变化特征,评价了区内2种草本和2种灌木植物降低边坡土体盐分的能力。结果表明:单一种植细茎冰草、紫花苜蓿、柠条锦鸡儿、霸王对边坡土体中SO4^2-、Ca^2+、Na^+具有显著降低作用,草本与灌木组合Ⅰ(柠条锦鸡儿+紫花苜蓿+细茎冰草组合)和草本与灌木组合Ⅱ(霸王+紫花苜蓿+细茎冰草组合)对边坡土体中SO4^2-、Ca^2+、Mg^2+、K^+、Na^+表现出显著降低作用;紫花苜蓿的降盐效果相对较为显著、其次为柠条锦鸡儿和细茎冰草,霸王的降盐效果不及前者显著;草本与灌木组合Ⅱ的降盐效果相对显著于草本与灌木组合Ⅰ。

Soil Salt Reduction Effect of Four Herbaceous and Shrubby Species in the Xining Basin,Qinghai Province

In this study,two shrubby species Caragana korshinskii Kom.and Zygophyllum xanthoxylon(Bunge)Maxim.and two herbaceous species Agropyron trachycaulum and Medicago sativa L.adaptive to the natural conditions in the Xining Basin were screened out to experimentally plant in the Changling Gully in the basin.In the research area,the four species were planted by means of single planting and assembled planting.The contents and variations of eight soluble salts including K^+,Ca^2+,Na^+,Mg^2+,SO4^2-,Cl^-,HCO3^-and CO3^2-in different soil layers and plant stems and roots under the two different planting conditions were discussed.The capabilities of two herbaceous and two shrubby species in reducing total salt content in slope soil were evaluated.The test results revealed that,under single planting of these four species,their effect in reducing the contents of SO4^2-,Ca^2+and Na+was significant,and that of herbaceous and shrubby assemblageⅠ(C.korshinskii+M.sativa+A.trachycaulum)and assemblage II(Z.xanthoxylon+M.sativa+A.trachycaulum)in reducing the contents of SO4^2-,Ca^2+,Mg^2+,K^+and Na^+in slope soil was significant.The salt reduction effect of M.sativa was relatively more significant,and then that of C.korshinskii and A.trachycaulu,but that of Z.xanthoxylon was not significant.The salt reduction effect of the herbaceous and shrubby assemblage II was significantly higher than that of the herbaceous and shrubby assemblage I.