氮素供应和pH值对玉米根系形态的影响  

Effect of Nitrogen Supply and Solution pH on Maize Root Morphology

作　　者：肖长新[1] 刘壬双[1] 陈范骏[1] 米国华[1] 

机构地区：[1]中国农业大学资源与环境学院,北京100193

出　　处：《玉米科学》2013年第5期113-116,共4页Journal of Maize Sciences

基　　金：国家自然科学基金(30171852;30771289)

摘　　要：实验设正常供氮（0.5 mmol/L NO3-）和高氮（10 mmol/L NO3-）处理,研究不同pH值水平下（4.5~8.0）氮素供应对玉米根系生长的影响。结果表明,氮供应与溶液pH值对玉米根系的影响不存在互作效应。高氮供应不影响地上部与根的干物质积累;pH值提高有利于促进干物质向地上部分配,向根的分配比例相对下降,根冠比下降。高氮使单株根系总长度平均下降,降幅为34.5%,主要是轴根和侧根长度下降,轴根数和侧根密度受影响较小。在两个氮水平下,总根长、轴根长、侧根长均随pH值的上升表现增加的趋势,高pH值主要增加侧根密度。研究表明,在酸性土壤上,不能通过大量施用硝态氮肥缓解氢离子对根系生长的抑制作用。The effect of high N treatments on maize root growth was investigated under varied pH（from 4.5 to 8.0） value in the culture solution supplied with either high（10 mmol/L） or normal（0.5 mmol/L） N.The results showed that there was not an interaction between the effect of N supply and solution pH value.Dry matter accumulation was not altered by high N treatment.High pH decreased dry matter allocation from shoot to root and therefore resulted in a lower root to shoot ratio.High N reduced total root length by 34.5% across different pH levels,which were mostly contributed by the decrease in the length of axial roots and lateral roots.Whereas the number of axial roots and lateral roots were not affected.Under both N levels,total root length,axial root length and lateral root length increased with increasing solution pH.It seems unable to alleviate the adverse effect of low pH on root growth in acidic soils by increasing N input.

关 键 词：玉米 根系 NO3- PH值 

分 类 号：S513.062[农业科学—作物学]