土壤干旱对黄土高原4个乡土禾草生长及水分利用特性的影响  

Effect of soil drought on growth and water use efficiency characteristics of four native gramineous grasses in Loess Plateau

作　　者：郭颖[1] 韩蕊莲[2] 梁宗锁[1,2] 

机构地区：[1]西北农林科技大学生命科学学院,陕西杨凌712100 [2]西北农林科技大学中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《草业学报》2010年第2期21-30,共10页Acta Prataculturae Sinica

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-YW-443);中国科学院西部行动计划项目(KZCX2-XB2-05-01)资助

摘　　要：应用盆栽试验,人工控制土壤水分含量对黄土高原4个乡土禾草长芒草、冰草、无芒隐子草、白羊草的生长及水分利用特性进行了研究。结果表明,随干旱胁迫程度加剧,各草种耗水量明显减少;不同草种单株耗水量差异明显,表现为:白羊草>冰草>无芒隐子草>长芒草,最高日、旬、月耗水量差异明显,中度和重度水分亏缺下的最高耗水日比适宜水分下的提前10 d左右。1 d中的最大耗水高峰随着土壤含水量的降低有提前的趋势。4个草种株高生长和单叶叶面积明显受土壤水分含量影响,均表现为:适宜水分>中度干旱>重度干旱,土壤干旱下长芒草和无芒隐子草受抑制程度显著大于冰草和白羊草;随干旱胁迫程度的加剧和干旱时间的延长,长芒草和无芒隐子草的叶片组织含水量和叶片相对含水量明显降低,冰草和白羊草则一直能维持较高含水量,且下降幅度小,稳定性好;长芒草和无芒隐子草的水分利用效率(water use efficiency,WUE)随干旱加剧而降低,两者属于低耗水、低WUE草种,冰草和白羊草在中度干旱下WUE最高,相比白羊草,冰草属于低耗水、高WUE草种,白羊草属于高耗水、高WUE草种。The growth and water use efficiency characteristics of four native grasses in Loess Plateau were studied under different soil water contents.The results showed that water consumption of those species decreased with the increase of soil drought stress,and water consumption of those grasses was different： Bothriochloa ischaemumAgropyron cristatumCleistogenes songoricaStipa bungeana.The highest water consumption in one day,ten-day and one month were different.The highest water consumption day of medium and severe drought stress occurred about 10 days earlier than the adequate soil water content.The time of day when the greatest water consumption occurred arrived early with the decrease of soil water contents.The growth of plant height and single leaf area of the four native grasses were the fastest under adequate soil water contents,and were the lowest under severe drought.Under drought condition,the growth of four grasses was all inhibited,especially for S.bungeana and C.songorica.The leaf water content of different species decreased with the increase of soil water stress.The leaf water content of A.cristatum and B.ischaemum were higher than that of S.bungeana and C.songorica obviously.Water use efficiency of S.bungeana and C.songorica decreased with the decrease of soil water content,they had lower water consumption and low WUE characteristics.A.cristatum and B.ischaemum had the highest WUE under medium drought treatments,respectively.A.cristatum had low water consumption and high WUE characteristic,B.ischaemum had high water consumption and high WUE characteristic.

关 键 词：黄土高原 乡土草种 耗水特性 生长 水分利用效率 干旱胁迫 

分 类 号：S54[农业科学—作物学]