不同水分条件下3种灌木幼苗的耗水及生长特征

目的]研究岳武高速公路填方边坡3种绿化灌木幼苗在不同土壤水分条件下的耗水特征及生长表现,为该地区边坡早期植被恢复和护坡植物维护提供参考。方法]选取马棘、二色胡枝子、紫穗槐幼苗为试验材料,采用盆栽称重法测定其在不同土壤水分处理下〔田间持水量(FC)的30%~45%,45%~60%,60%~75%和75%~90%〕的阶段耗水特征及生长变化。结果]3种灌木幼苗的日耗水变化曲线均呈单峰型特征,峰值出现在中午时分;月耗水量、总耗水量均随土壤含水量的升高而增大,且差异显著;不同水分条件下灌木幼苗的株高、地径、生物量增量差异显著,马棘长期处于30%~45%FC、二色胡枝子和紫穗槐长期处于30%~45%FC,45%~60%FC水分条件下其幼苗生长受到抑制;土壤水分含量对灌木幼苗的水分利用效率影响较大,75%~90%FC和30%~45%FC均会降低幼苗的水分利用效率。结论]综合考虑灌木幼苗的耗水量及生长特征,认为马棘幼苗土壤含水量维持在45%~60%FC、胡枝子和紫穗槐维持在60%~75%FC时能够实现幼苗正常生长,同时又能实现水分的高效利用。

Water Consumption and Growth Characteristics of Three Shrubs Seedlings Under Different Soil Water Conditions

Objective] The water consumption characteristics and growth performances of three shrubs seed lings on the embankment slope of Yuexi-Wuhan highway under different soil water conditions were studied to provide a theoretical basis for the local slope vegetation restoration and plants maintenance of slope protection.Methods] Three shrubs,Indigo f era pseudotinctoria,Lespedeza bicolor and Amorpha f ruticosa were cultivated using pot method.Water consumption and seedlings growth of them were measured under four different water treatments 30％～45％,45％～60％,60％～75％ and75％～90％ of the field watercapac ity(FC)of pot soil].Results] Result indicated that the diurnal variation of water consumption of the three shrub seedlings presented an unimodal shape.The peak values appeared in the noon.The monthly water consumption and total water consumption increased significantly with the increase of soil moisture.There ex isted significant differences in height,basal diameter and biomass increment for all of the three shrub seedlings among different soil water content.The growth of Indigofera pseudotinctoria in long time of 30％ ～45％ FC,and the growths of Lespedeza bicolor and Amorpha fruticosa in long time of 30％～45％ FC and 45％～60％ FC,respectively were inhibited.Soil water content had a great influence on the water use efficiency of three shrubs seedlings.Soil water conditions of 75％～90％ FC and 30％～45％ FC reduced the water use efficiency(WUE).Conclusion] If seedlings water consumption and growth characteristics were both considered,soil moisture of Indigofera pseudotinctoria should maintain at 45％ ～60％ FC,Lespedeza bicolor and Amorpha fruticosaat 60％～75％ FC.On these conditions of soil moisture,they can grow at normal rate with relative efficient uses of water.