Abstract: The Biomass and root vertical distribution of Atriplex canescens(Pursh) Nutt.under different cutting frequencies were studied in the field.The results show that cutting frequency had significant effects on the aboveground and underground biomass allocation and root vertical distribution of A.canescens(P<0.01).Firstly,with the increasing of cutting frequency,the aboveground biomass increased at the beginning and then decreased with highest accumulated biomass of 14.26 g plant^-1 under two cutting times and the contents of crude protein,crude fat,ash,and N-free extract were always increased,but the crude fibre decreased gradually.Secondly,as the cutting frequencies increased,the taproot diameter,root system volume,root system biomass,and rude root percentage were decreased significantly(P<0.05),the root distribution in soil layer of 40 to 70 cm was reduced,and that in shallow soil layer of 0 to 20 cm increased significantly.The characteristic parameters(H⁰) of root vertical distribution under all cutting treatments were smaller than that of the control and decreased gradually along with the increasing of cutting frequency.

Key words: Atriplex canescens(Pursh) Nutt., Cutting frequencies, Biomass, Root vertical distribution

摘要： 为科学指导四翅滨藜(Atriplex canescens(Pursh)Nutt.)在我国西北沙区的生产和利用,研究不同刈割处理下四翅滨藜生物量变化及其根系垂直分布。结果表明:刈割频度对四翅滨藜的地上、地下部分生物量积累均有极显著影响(P<0.01),地上生物量随刈割频度增大而先增大后减小,2次刈割生物量最大,单株均值高达14.26g;粗脂肪、粗蛋白、粗灰粉及无氮浸出物百分比随着刈割频度的增大而增大,而粗纤维则逐渐减小;当刈割次数逐渐增加时,主根直径、根系体积、根系生物量及粗根百分比均显著减小(P<0.05),根系在土壤深层(40~70cm)中的分布也减少,而在浅土层中(0~20cm)的分布明显增大;4组刈割处理的根系垂直分布特征参数β的值均小于对照(H₀),并随刈割频度增大其值逐渐减小。

关键词: 四翅滨藜, 刈割频度, 生物量, 垂直分布