生长期紫穗槐含水量和生长量变化规律及与土壤水分的关系

Water content of Amorpha fruticosa and its relationships with soil moisture in different growth stages

以试验地种植的3年生紫穗槐为研究对象，运用烘干方法，测定其不同生长期的茎、叶、株含水量、单株地上生物量以及土壤含水量。结果表明，紫穗槐茎、叶含水量平均为57．49％、64．10％，具有很强的吸水性和保水性；生长初期鲜干比较高，为2．07～4．70，适口性好，刈割作为青饲料较好，生长后期鲜干比低为1．86，刈割宜晒制干草；茎叶比逐月递增，从6月初0．74增加到9月初1．71；茎、叶及整株含水量、鲜干比、茎叶比之间存在一定的相关性；紫穗槐茎、叶鲜干重均随生长期逐渐增加，叶和茎的干物质分别在7、8月，7、9月迅速积累；紫穗槐单株地上茎、叶以及总生物量与不同深度土壤含水量呈显著的负相关关系。

3 years old Amorpha fruticosa planed in experimental field was used to study the water content and its relationships with soil moisture in different growth stages. The results showed that average water con tents of stem and leaf（57.49% and 64. 10%）were much higher than soil moisture in different depths（5.31% , 5.59% and 5.28%）,so it had a strong water absorption and water holding capacity;the GW/DW ratio was high and GW/DW ratio was low, which suggested that Amorpha frulicosa was suitable for green fodder in early growth stage and hay making in late growth stage;the stem/leaf ratio increased monthly from 0.74 in early June to 1.71 in early September; there was a certain correlation among water content of stems, leaves anti whole plant,the GW/DW ratio and the stem/leaf ratio; both fresh and dry weight of stems anti leaves were increased with the growth period,dry matter of leaf and stem accumulated rapidly from July to August and July to Sep tember respectively; regression analysis indicated that stems, leaves and total aboveground biomass per plant showed a significant negative correlation with soil moisture in different depths.